2-2 GROUP 2 - BRAKESTABLE 1-Disc Brake Trouble Symptoms and Possible Causes TROUBLE SYMPTOMS u rn e; - - .- e B.a -2 .- w Possible Causes of - : c" n .z - e Trouble Symptoms U 2 :. = E "na= r.~, u h = = - al h h g = u QJ - .- e - 51 = w a -, r" L Un ~ a n z -&B2 c.- e; a : .- n w n Ma g a O Y x al al C m Y Y Y cum Z LShoe and Lining Knock-back after violent cornering or rough road travel XPiston and Shoe and Lining Assembly Not Properly Seated or Positioned X XAir Leak or Insufficient Fluid in System or Caliper X X
PART 2- 1 - GENERAL BRARE SERVICE 2-3TABLE 2-Drum Brake Trouble Symptoms and Possible Causes Possible Causes of Trouble Symptoms Sticking Booster Control Valve I
GROUP 2 -BRAKESBRAKE BOOSTER TROUBLE DIAGNOSIS GUIDE If the preliminary tests show that leaking or collapsed condition. Re- the booster is inoperative or if a pair or replace parts as necessary. hard pedal condition still exists after If the foregoing procedure does eliminating the causes of Hard not eliminate the trouble, remove Pedal listed in Table 2, the trouble the booster from the car. Separate may be caused by vacuum leakage. the booster body from the end plate, BOOSTER INOPERATIVE- Disconnect the vacuum line (two and check the bellows, booster body, HARD PEDAL lines if equipped with an automatic and diaphragm assembly for damage transmission) at the booster, remove that would cause leaks. When assem- the vacuum manifold and check bling, be sure that the diaphragm as- valve assembly, and look for a stick- sembly is properly positioned. Im- ing or faulty check valve. Check all proper location could cause leakage vacuum connections for leakage or between the vacuum and atmos- obstruction. Check all hoses for a pheric sides of the diaphragm. If the brakes still drag or grab assembly. Remove and disassemble BRAKES DRAG OR GRAB after eliminating the causes listed in the booster. Clean, inspect, and re- Table 1, the condition is probably place parts as necessary. caused by a sticking valve plunger SELF APPLICATION Remove and disassemble the seated atmospheric valve. Clean, in- O F BRAKES W H E N booster. Check the diaphragm for spect, and replace parts as necessary. ENGINE STARTS being out of locating radii in the Be sure that the diaphragm is prop- housing. Check for a sticking or un- erly located when assembling. COMMON ADJUSTMENTS AND REPAIRSPARKING BRAKE pedal one notch from its normal that the end of the screw just touchesLINKAGE ADJUSTMENT released position. the inner edge of the slot in the 3. Raise the car. gauge. Do not set up side forces onMUSTANG 4. Loosen the equalizer lock nut the push rod. Side forces may break Check the parking brake cables and turn the adjusting nut forward the valve plunger.when the brakes are fully released. against the equ&zer-until a mod- This is an approximate adjustmentIf the cables are loose, adjust them erate drag is felt when turning the only. The push rod should not moveas follows: rear wheels (Fig. 2). Tighten the more than 0.015 inch as it contacts 1. Fully release the parking brake lock nut. the master cylinder piston. No move-by turning the handle counterclock- 5. Release the parking brake, ment (exact contact) is ideal.wise and pushing it inward. and make sure that the brake shoes . 2. Pull the parking brake handle return to the fully released position. HYDRAULIC SYSTEMoutward to the third notch from its BLEEDINGnormal released position. POWER BRAKE MASTER When any part of the hydraulic 3. Raise the car. CYLINDER PUSH ROD system has been disconnected for re- 4. Turn the locking adjustment nut ADJUSTMENT pair or replacement, air may getforward against the equalizer (Fig. The push rod is provided with an into the lines and cause spongy pedal1) until a moderate drag is felt when adjustment screw to maintain the action. Bleed the hydraulic systemturning the rear wheels in the direc- correct relationship between the after it has been properly con-tion of forward rotation. booster control valve plunger and nected to be sure that all air is 5. Release the parking brake, and the master cylinder piston. Failure expelled from the brake cylindersmake sure that the brake shoes to maintain this relationship will pre- or disc brake calipers, and lines.return to the fully released position vent the master cylinder piston from The hydraulic system can be bledand no drag is felt when turning the completely releasing hydraulic pres- manually or with pressure bleedingrear wheels. sure and can cause the brakes to equipment. drag, or cause excessive brake pedal With disc brakes, more pumpingCOMET-FALCONFAIRLANE travel. of the pedal is required and more Check the parking brake cables T o check the adjustment of the frequent checking of the master cyl-when the brakes are fully released. screw, fabricate a gauge of the di- inder may be necessary while bleed-If the cables are loose, adjust them mension shown in Fig. 3. Then place ing.as follows: the gauge against the master cylin- On a car with disc brakes, remove 1. Fully release the parking brake der mounting surface of the booster the front wheels and tires to gainpedal. body as shown in Fig. 4 or 5. The access to the bleeder fitting on the 2. Depress the parking brake push rod screw should be adjusted so disc brake calipers.
PART 2-1 -GENERAL BRAKE SERVICE 2-5 FRONT CABLEFIG. 1-Parking Brake Linkage-Mustang ADJUSTMENT NUT LOCKNUT r #16 G A U G E SHEET STEEL EQUALIZER H 1405-AFIG. 2-Parking BrakeLinkage Adjustment Comet-Fairlane-Falcon FIG. 4-Push Rod AdjustmentMANUAL BLEEDING -Midland-Ross Bleed the longest lines first. Keepthe master cylinder reservoir filled 1. Position a bent %-inch boxwith new Rotunda R-103-A (B7AZ- wrench on the bleeder fitting on the19542-A) brake fluid during the rieht rear brake wheel cylinder (Fig.bleeding operation. 14,208-B 6; Attach a rubber drain tube to Never use brake fluid which has the bleeder fitting. The end of thebeen drained from the hydraulic sys- FIG. 3-Push Rod Gauge tube should fit snugly around the -tem. Dimensions bleeder fitting.
GROUP 2 - BRAKES 4. When the fluid is completely sealed o n the master cylinder o r free of air bubbles, close the bleeder leakage will occur. fitting and remove the drain tube. 3. Position a %-inch box wrench 5. Repeat this procedure o n the on the bleeder fitting on the right brake cylinders o r disc calipers at rear brake wheel cylinder (Fig. 6). each wheel in order: left rear, right Attach a rubber drain tube to the front, and left front. Refill the mas- bleeder fitting. The end of the tube ter cylinder reservoir after each should fit snugly around the bleeder brake cylinder is bled and when the fitting. bleeding operation is completed. T h e 4. Open the valve o n the bleeder fluid level should be within 3/8 inch tank to admit pressurized brake fluid of the top of the reservoir. T h e dia- to the master cylinder reservoir. phragm-type gasket should be prop- 5. Submerge the free end of the erly positioned in the reservoir cap tube in a container partially filled before the cap is installed. with clean brake fluid, and loosen 6. On a car with disc brakes, the bleeder fitting. pump the brake pedal until the front 6 . When air bubbles cease to ap- brake pistons are returned to their pear in the fluid at the submerged normal positions and that the shoe end of the drain tube, close the and lining assemblies are properly / seated. bleeder fitting and remove the tube. FIG. 5-Push-Rod Adjustment- 7. Before driving the car, check 7. Repeat this procedure on the Bendix the operation of the brakes and be brake cylinder o r disc caliper at each sure that a firm pedal is obtained. wheel in order: left rear, right front, APPROXIMATELY 45" and left front. Refill the master cyl- PRESSURE BLEEDING inder reservoir after each brake cyl- Bleed the longest lines first. Never inder is bled. use brake fluid which has been 8. When the bleeding operation is drained from the hydraulic system. completed, close the bleeder tank The bleeder tank should contain valve and remove the tank hose from enough new heavy-duty brake fluid the adapter fitting. to complete the bleeding operation, 9. ~ k m o v ethe adapter cap, re- and it should be charged with 10-30 fill the master cylinder reservoir to pounds of air pressure. within %-inch from the top of the FIG. 6-Brake Bleeder Wrench reservoir. Be sure that the dia- 1. Clean all dirt from the master 2. Submerge the free end of the cylinder reservoir cap. phragm-type gasket is properly po- tube in a container partially filled 2. Remove the master cylinder sitioned in the reservoir cap, and then with clean brake fluid. Loosen the reservoir cap, install an adapter install the cap. bleeder fitting approximately % turn. I cap to the reservoir, and attach the 10. On a car with disc brakes, 3. Push the brake pedal down bleeder tank hose to the fitting on pump the brake pedal until the front slowly through its full travel. Close the adapter cap. brake pistons are returned to their the bleeder fitting, then return the An adapter cap can be fabricated normal positions and the shoe and pedal to the fully-released position. byecutting a hole in the center of a lining assemblies are properly seated. Repeat this operation until air reservoir cap and smoldering a fitting + 11. Before driving the car, check bubbles cease to appear at the sub- at the hole. T h e adapter cap must the operation of the brakes and be merged end of the tube. b e , securely seated and completely sure that a firm pedal is obtained. CLEANING AND INSPECTIONIII DISC BRAKES 1. Remove the wheel and tire, 3. With the shoe and lining as- semblies installed, insert a feeler 4. T o check rotor runout, first eliminate the wheel bearing end play caliper splash shield, and the shoes gauge between the lining and rotor. by tightening the adjusting nut. and linings as outlined in Part 2-2, If the clearnace is not within 0.002- After tightening the nut make cer- Section 2. 0.010-inch, check for shoe and lining tain that the rotor can still be ro- 2. Make three thickness measure- assemblies not being properly seated tated. ments with a micrometer across the on the caliper bridges, for a piston 5. Clamp a dial indicator to the middle section of the shoe and lin- pushed back in the cylinder bore, for caliper housing so that the stylusi ing. T a k e one reading a t each side a seized piston, o r for malfunction contacts the rotor at a point approxi- and one in the center. If the assem- of a piston seal. mately 1 inch from the outer edge. bly has worn to a thickness of Ordinarily, the clearance should Rotate the rotor and take an indica- 0.195-inch (shoe and lining together) be 0.002-0.010 inch. However, if the tor reading. If the reading exceeds at any one of the three measuring lo- car was stopped by a brake applica- 0.0025 inch total indicator runout, cations, replace all (4) shoe and lin- tion just prior to checking the clear- replace the rotor. D o not attempt to ing assemblies on both front wheels. ance, the brakes may drag slightly. refinish a rotor that indicates runout
PART 2-1 - GENERAL BRAKE SERVICEin excess of specification. When the 3. Inspect the brake shoes for ex- and replace any that are worn orrunout check is finished be sure to cessive lining wear or shoe damage. damaged.adjust the bearings as outlined in If the lining is worn to within 132 7. Inspect the brake drums and,Group 3, in order to prevent bearing inch of the rivet heads or if the if necessary, refinish. Refer to Partfailure. shoes are damaged, they must be re- 2-2, Section 4 for refinishing. 6. Check the rotor for scoring. placed. Replace any lining that hasMinor scores can be removed with been oil saturated. Replace the lin- BOOSTER UNITSa fine emery cloth. If the rotor is ing in axle sets. Prior to replacement Disassembled views of the brakeexcessively scored, replace it. of the lining, the drum diameter booster are shown in Figs. 40, 49 and 7. Visually check the caliper. If it should be checked to determine if SO, Part 2-2.is cracked it should be replaced. If oversize linings must be installed. After disassembly, immerse allleakage o r seized pistons is evident, 4. Check the condition of the metal parts in a suitable solvent.disassemble and repair the caliper as brake shoes, retracting springs, and Use-only alcohol on rubber parts o rrequired. drum for signs of overheating. If the parts containing rubber. After the 8. If upon disassembly the caliper shoes have a slight blue coloring, or parts have been thoroughly cleanedis found to be distorted or damaged, if the springs show a change in free and rinsed in cleaning solvent, theor if the cylinder bores are scored length, indicating overheating, re- metal parts which come in contactor excessively worn, replace the as- placement of the retracting and hold with hydraulic brake fluid or rub-sembly. down springs is necessary. Over- ber parts should be rewashed in The two halves of the caliper as- heated springs lose their force and clean alcohol before assembly. Usesembly should never be separated. could cause the new lining to wear an air hose to blow dirt and cleaningDamage or failure of one requires prematurely if they are not replaced. fluid from the recesses and internalreplacement of both as a unit. 5. If the car has 30,000 or more passages. When overhauling a power miles of operation on the brake lin- booster, use all parts furnished in theD R U M BRAKES ings, or signs of overheating are repair kit. Discard all old rubber 1 Remove the wheel from the . present when relining brakes, the parts.drum, and remove the drum as out- wheel cylinders should be disassem- Inspect all other parts for damagelined in Part 2-2, Section 2. Wash bled and inspected for wear and dirt or excessive wear. Replace damagedall the parts except the brake shoes in the cylinder. The cylinder cups or excessively worn parts. If the in-in a cleaning fluid and dry with com- and other parts contained in the side of the booster body is rustedpressed air. overhaul kit should be replaced, or corroded, polish it with steel wool 2. Brush all dust from the carrier thus avoiding future problems. or fine emery cloth.plate and interior of the brake drum. 6. Inspect all other brake parts
PART BRAKE SYSTEM .Section Page Section Page 1 Description and Operation . . . . . . . . . . . . . . . . ..2-8 Hydraulic Lines . . . . . . . . . . . . . . . . . . . . . . . . .2-24 Hydraulic Self-Adjusting Brake System . . . . . . .2-8 Brake Tube Replacement . . . . . . . . . . . . . . . . .2-24 Disc Brake Assemblies . . . . . . . . . . . . . . . . . . .2-8 . Brake Hose Replacement . . . . . . . . . . . . . . . . . ..2-24 Booster System-Bendix . . . . . . . . . . . . . . . . . .2-11 3 Removal and Installation . . . . . . . . . . . . . . . . .2-24 Booster System-Midland-Ross . . . . . . . . . . . .2-13 Master Cylinder-Standard Brakes . . . . . . . . .2-24 Parking Brake . . . . . . . . . . . . . . . . . . .: . . . . . .2-14 . Master Cylinder-Power Brakes . . . . . . . . . .2-24 2 In-Car Adjustments and Repairs . . . . . . . . . . ..2-16 . Booster Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-25 Brake Shoe Adjustments . . . . . . . . . . . . . . . . ..2-16 Brake Pedal-Manual Shift Transmission ... .2-25 Front Brake Drum . . . . . . . . . . . . . . . . . . . . . . . .2-17 Brake Pedal-Automatic Transmission . . . . . .2-27 Rear Brake Drum . . . . . . . . . . . . . . . . . . . . . . ..2-17 Parking Brake Control Assembly . . . . . . . . . . . .2-27 Brake Shoes and Adjusting Screw . . . . . . . . . . .2-17 . Parking Brake Equalizer to Control Cable . . . .2-27 Disc Brake Shoe and Lining Replacement . . . .2-18 Parking Brake Equalizer to Rear Wheel Cable .2-30 Disc Brake Caliper Assembly . . . . . . . . . . . . .2-19 4 Major Repair Operations . . . . . . . . . . . . . . . . .2-3 1 Front Wheel Hub and Rotor Assembly-Disc Brake Drum Refinishing . . . . . . . . . . . . . . . . . ..2-3 1 Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19 Brake Shoe Relining . . . . . . . . . . . . . . . . . . . . .2-3 1 Disc Brake Rotor Splash Shield . . . . . . . . . . . . .2-20 Master Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . .2-3 1 Proportioning Valve . . . . . . . . . . . . . . . . . . . . .2-20 Disassembly of Bendix Type Booster . . . . . . . . .2-33 Wheel Cylinder Repair . . . . . . . . . . . . . . . . . . ..2-21 Assembly of Bendix Type Booster . . . . . . . . .2-34 Wheel Cylinder Replacement . . . . . . . . . . . . . . .2-2 1 Disassembly of Midland-Ross Type Booster . . .2-35 Brake Carrier Plate Replacement . . . . . . . . . . . .2-24 Assembly of Midland-Ross Type Booster . . . . .2-36 DESCRIPTION AND OPERATION Disc brakes are available as op- ondary brake shoe by means of the gressively wear.tional equipment for the front wheels cable guide. The adjuster spring is With the car moving forward andon Mustang 8-cylinder cars. The hy- hooked to the primary brake shoe the brakes applied, the secondarydraulic brake system employs duo- and to the lever. The automatic ad- shoe is against the anchor pin andservo single anchor, internal expand- juster operates only when the brakes the primary shoe is moved towarding and self-adjusting drum brake as- are applied while the car is moving the drum.. Therefore, the adjustersemblies on the rear wheels of cars rearward and only when the second- does not operate.with disc brakes, and of front and ary shoe is free to move toward the The rear brake assembly is basic-rear wheels of all others. drum beyond a predetermined point. ally the same as the front brake. A vacuum booster is available as With the car moving rearward The conventional parking brakeoptional eqipment on all models ex- and the brakes applied, the wrap- lever, link, and spring are used incept Mustangs equipped with disc around action of the shoes follow- the rear brake.brakes. ing the drum forces the upper end The anchor pins on all brakes are The master cylinder converts phys- of the primary shoe against the fixed and are non-adjustable.ical force from the brake pedal anchor pin. The action of the wheel(and booster if so equipped) into cylinder moves the upper end of thehydraulic pressure against the pistons secondary shoe away from the an- DISC BRAKE ASSEMBLIESin the calipers (disc brakes) or in chor pin. The movement of the sec-the wheel cylinders (drum brakes). ondary shoe causes the cable to pull RELATION AND FUNCTION OFThe pistons in turn convert hy- the adjusting lever upward and COMPONENT PARTSdraulic pressure back into physical against the end of a tooth on the The disc brake is a fixed caliper,force at the brake shoes. adjusting screw star-wheel. The up- opposed piston, non-energized, venti- ward travel of the lever increases as lated disc type, actuated by a hy-SELF ADJUSTING D R U M lining wear increases. When the lever draulic system (Fig. 3). There is noBRAKE ASSEMBLIES can move upward far enough, it lateral movement of either the disc The self-adjusting brake mecha- passes over the end of the tooth and (rotor) or the caliper. The calipernism consists of a cable, cable guide, engages the tooth. When the brakes assembly consists of two caliperadjusting lever, and adjuster spring are released, the adjusting spring housings bolted together with each(Fig. 1 and 2). The cable is hooked pulls the lever downward causing the half containing two cylinder boresover the anchor pin at the top and is star-wheel to turn and expand the of l1jllc; inch diameter. Each cylinderconnected to the lever at the bottom. shoes. The star-wheel is turned one bore contains a piston with an at-The cable is connected to the sec- tooth at a time as the linings pro- tached molded rubber dust boot to
PART 2-2 - BRAKE SYSTEM 2-9 ,RKING B A E RK fER RETAINING RKlNG B A E RK REAR BRAKE FRONT BRAKE H 1323-AFIG. I-Self-Adjusting Brake Assemblies-9 lnch Drum C B E ANCHOR AL PARKING B A E L V R R K EE RETAININGCLIP WaCUFP PARKING B A E LINK RKFG I. 2-Self Adjusting Brake Assemblies-10 lnch Drumseal the cylinder bore from contami- 2. They return the pistons to re- draulically by means of internal pas-nation. (Fig. 4). Square-section rub- leased position, when hydraulic pres- sages in the caliper housing and anber piston seals are positioned in sure is released. external transfer tube between thegrooves in the cylinder bores. 3. They maintain the shoes in cor- two halves of the caliper assembly. The piston seals perform three im- rect adjustment at all times (com- One bleeder screw and fluid inletportant tasks: parable to the automatic adjusters in fitting is provided on each caliper 1. They provide hydraulic sealing drum-type brakes). assembly.between the cylinders and pistons. The cylinders are conneced hy- The shoe and lining assemblies are
GROUP 2 - BRAKES CALIPER TOROTORCLEARANCE I TRANSFER TUBE CALIPER HOUSING PISTON DUST BOOT RETAINING GROVE PISTON SEAL CALIPER DUST BOOT RETAINER BLEEDER SCREW / CALIPER ASSEMBLY I CALIPER SPLASH-SHIELD H1369-A FIG. 4-Typical Caliper Assembly-Sectional ViewFIG. 3-Typical Disc Brake OPERATION matic adiustment is achieved bv theAssembly pistons sliding in the seals outward As the brake pedal is depressed, from the cylinder bores. The piston hydraulic pressure from the master gradually changes its position rela-located between parallel machined cylinder forces the pistons out of theabutments within the caliper, and tive to the seal as the lining wears caliper bores against their respective and, thus, maintains the correct ad-are supported radially by tabs on the shoe and lining assemblies. Theouter ends of the shoe assemblies justment location at all times. force of the pistons against the shoes When the brakes are in the un-(Fig. 35). The shoes slide axially in moves the linings against both sidesthe caliper abutments by means of applied position, there is no hydrau- of the revolving rotor to effect brak- lic pressure to the calipers becausethe tabs which ride on machined ing action.ledges (bridges) when hydraulic pres- the fluid source at the master cvlin-sure is applied to the piston (Fig. During brake application, the rub- der by-passes the resid"a1 check19). A shoe and lining assembly con- ber seal on each piston stretches as valve.sists of friction material bonded to a the piston moves against the shoe A warning sound feature is incor-metal plate called the shoe. It is re- (Fig. 5). When the hydraulic pres- porated in the design of the brakeplaced as a unit. Brake torque is ab- sure against the piston is released, shoes. Metal tabs on the ends ofsorbed by the mating of the shoe end the seal relaxes or rolls back. This the shoes create an audible metallic,against the caliper abutments (Fig. roll-back action pulls the piston scraping noise, when the linings be-35). A splash shield is attached to away from the shoe approximately come worn enough to allow the tabsthe top of the caliper to retain the 0.005 inch to relieve the force of to contact the rotor. This metal-to-shoe and lining assemblies and re- the lining against the rotor and, metal contact warns the driver thatduce contamination. The caliper as- thereby, provide the required run- the shoes need replacing and is notsembly is mounted to a bracket lo- ning clearance. Also, inherent rotor detrimental to the function of thecated between the spindle and rotor runout contributes to the mainte- disc brake.splash shield, to the front of the nance of running clearance. Auto- A proportioning valve located be-wheel vertical centerline. The cast iron disc is of the venti- PISTONlated rotor type incorporating fortyfins and is staked to, and rotateswith, the wheel hub. The outsidediameter of the rotor is 11.375 F inches and the inside diameter is7.375 inches. This type of design increases cooling area and permits circulation of air through the rotor resulting in more rapid cooling of the brake. A splash shield bolted to the spindle is used primarily to pre-vent r6ad contaminants from con- DUST BOOT tacting the inboard rotor and liningsurfaces (Fig. 20). The wheel pro- BRAKES APPLIED * BRAKES RELEASED H1370-B 1vides protection for the outboard surface of the rotor. FIG. 5-Function of Piston Seal
BART 2-2 - BRAUE SYSTEMtween the master cylinder and the rear shell. A synthetic rubber seal site end has a piston head whichrear brake wheel cylinders provides is used between the valve hub and enters the diaphragm plate. A seal,balanced braking action between the the rear shell. The seal and the valve located in the front shell, seals thefront and the rear brakes under a hub are protected from dirt by a opening between the hydraulic pushwide range of braking conditions. rubber guard connected between the rod and the shell.(Fig. 21). By regulating the hydrau- air filter at the end of the hub and Engine manifold vacuum is sup-lic pressure applied to the rear wheel a flange on the rear shell. The con- plied to the booster through acylinders, the valve limits rear brak- trol valve assembly fits into the hub vacuum check valve located in theing action when high pressures are and is connected to the brake pedal front shell. Air is admitted throughrequired at the front brakes. In this by the valve operating rod. The con- the air filter located at the end ofmanner, premature rear wheel skid trol valve assembly consists of a the valve hub. The hydraulic pushis prevented. The proportioning plunger, a valve body which supports rod is actuated by pedalvalve is serviced as an assembly and a single poppet of flexible rubber, assisted by the diaphragm, which de-is never adjusted or overhauled. and two return springs. When the rives power from the pressure differ- brake pedal is in the released posi- ential existing between the vacuumBOOSTER SYSTEM-BENDlX tion the valve return spring holds on its front side and atmosphericTYPE the valve assembly and operating rod pressure on its rear side. A passage away from the diaphragm plate. In in the diaphragm plate permits The diaphragm type brake booster this position, the poppet on the valve vacuum to pass from the front tois a self contained vacuum-hydraulic body is off the vacuum port seat the rear side of the diaphragm whenbraking unit mounted on the engine which is a part of the diaphragm the vacuum port opens as the brakesside of the dash panel. plate. The poppet return spring l i k e are released. The vacuum power chamber con- wise holds the poppet against thesists of a front and rear shell locked atmospheric port seat which is a parttogether. Within the vacuum cham- RELEASED POSITION of the plunger.ber are the rubber diaphragm and The hydraulic master cylinder With the engine running and thethe integral valve hub and diaphragm which contains all of the components brakes released (Fig. 7), vacuumplate. The rubber diaphragm fits of the conventional master cylinder from the intake manifold is adrnit-over the plate, and the outer bead is bolted to the booster front shell. ted through the check valve to theof the diaphragm is locked between The hydraulic push rod forms the front (constant vacuum) chamber ofthe front and rear shells (Fig. 6). link between the master cylinder pis- the power unit. Zn the released posi-The diaphragm return spring is lo- ton and the vacuum power dia- tion (no pressure applied to the brakecated between the diaphragm plate phragm assembly. The end of the pedal), the valve operating rod andand the front shell. push rod, that enters the master cyl- valve plunger are held to the rear The valve hub section of the dia- inder piston, is equipped with a self- in the valve hub by the valve returnphragm plate protrudes from the locking adjusting screw. The oppo- spring to CLOSE the atmospheric REAR SHE1MASTER CYLINDER FRONT S H E L L /F G 6-Cutaway View of Vacuum Booster-Bendix-Type I.
GROUP 2 - BRAKES push rod and master cylinder piston forward to close the compensating port and force hydraulic fluid under pressure through the residual check valve and brake tubes into the brake wheel cylinders. As hydraulic pres- sure is developed in the brake master cylinder, a counter force (to. the rear) acting through the hydraulic push rod, sets up a reaction force against the power diaphragm assem- bly and valve plunger through the rubber reaction disc (located at the end of the hydraulic push rod). The rubber reaction disc acts similar to a column of fluid to distribute the pressure between the vacuum power diaphragm assembly and the valve plunger in proportion to their re- spective contact areas. The pressure acting against the valve plunger and valve hub assembly to close off the the valve plunger slightly to the rear in relation to the diaphragm and valve hub assembly to close off the H1325-A atmospheric port. The driver is thus assured a feel of the brake, sinceFIG. 7-Booster in Released Position-Bendix-Type part of the counter force reactsport and OPEN the vacuum port. admit atmosphere through the air through the plunger, p-With the valve in this position, the cleaner and passages in the dia- crating rod* and pedal linkagerear (control vacuum) chamber is phragm plate to the rear side of the against the drivers foot. This re-also open to vacuum through the power chamber. With vacuum action force s in direct proportionporting in the diaphragm and valve present on the front side of the dia- the pressurehug assembly. The diaphragm is then phragm and valve housing and at- the brake ystem.balanced or suspended in vacuum, mospheric pressure present on thesince vacuum is present on both rear side of the diaphragm, a force HOLDING POSITIONsides of the power diaphragm. With is developed to move the vacuum During brake application, the re-the power diaphragm balanced in power diaphragm assembly, hydraulic action force which opposes thevacuum, the diaphragm return springholds the diaphragm and hydraulicpush rod in the fully released posi-tion. With the hydraulic push rod inthis position, the hydraulic compen-sating port in the hydraulic mastercylinder is OPEN. The open portpermits brake fluid to either returnfrom the brake system to the fluidreservoir or enter the brake systemfrom the fluid reservoir to compen-sate for any gain or loss in fluidvolume.APPLIED POSITION When the brakes are applied (Fig.8), the valve operating rod and valveplunger move forward in the valvehub section of the diaphragm plateto compress the valve return springand force the poppet against the vac- IC PORT OPENuum valve seat in the diaphragmplate to CLOSE the vacuum port.Any additional movement of the valve operating rod in the applieddirection moves the valve plungeraway from the poppet valve toOPEN the atmospheric port and FIG. 8-Booster in Applied Position-Bendix-Type
PART 2-2 - BRAKE SYSTEMforce applied by the driver, tends to power brake application may be and vacuum chamber, it is possibleclose the atmospheric port. When made from the vacuum in the to obtain several power assistedboth atmospheric and vacuum ports booster. With the engine off and no brake applications with the engineare CLOSED, the booster is said to vacuum in the power system, the shut off. This arrangement makes abe in the holding position (Fig. 9). brakes can be applied in the conven- vacuum reservoir unnecessary. Wither vacuum from the forward side of the diaphragm or air from the bellows (atmospheric chamber) can be connected to the rear side of the diaphragm through porting in the ,control valve hub and the plunger assembly. APPLYING POSITION As the brake pedal is depressed, the valve operating rod and valve plunger assembly move forward compressing the plunger return spring (Fig. 10). The initial move- ment of the plunger closes the port- ing from the vacuum chamber pre- venting further evacuation of the area back of the diaphragm. Fur- - - ther movement of the plunger forces the atmospheric valve off its seat so that atmospheric pressure from the bellows can enter the hub porting that leads to the rear side of the diaphragm. With vacuum on the front side of VACUUM SOURCE the diaphragm and atmospheric H 1327-A pressure on the back side of the dia-FIG. 9-Booster in Holding Position-Bendix-Type phragm, a force is developed to move the diaphragm, push rod and master cylinder piston forward toWith both valves closed, any degree tional manner by applying moreof brake application attained will be close the compensating port and physical effort to the brake pedal. force hydraulic fluid under pressureheld until either the atmospheric through the residual pressure checkport is reopened by an increase in BOOSTER SYSTEM- valve and brake tubes to the wheelpedal pressure to further increase the MIDLAND-ROSS brakes. As hydraulic pressure is de-brake application or by a decrease The optional power brake booster veloped in the hydraulic system, ain pedal pressure to reopen the vac- is installed on the engine side of the reaction counter-force acts againstuum port to decrease the brake ap-plication. Whenever the pressure ap- dash panel and is connected to the the reaction lever and ring assembly. brake pedal through a lever assem- This reaction lever and ring assem-plied to the brake pedal is held con- bly is designed to transmit the reac-stant for a moment, the valve bly and push rod link. The booster consists of a vacuum tion forces back through the actuat-returns to its holding position. How- chamber, atmospheric valve, control ing control valve assembly to theever, upon reaching the fully applied valve plunger assembly, diaphragm, brake pedal and provide the driverposition the force applied to thebrake pedal overrules the reaction and an atmospheric chamber (Figs. with a resistance that is in propor-force. In this position the valve 10, 11 and 12). tion to the brake hydraulic apply Atmospheric pressure is present at forces. This is the means of provid-plunger and atmospheric valve seatare held away from the valve poppet all times in the atmospheric cham- ing the proper driver feel to theto admit maximum atmospheric pres- ber at the front side of the atmos- power brake unit.sure to the rear chamber. With the pheric valve. The air intake to thefront chamber open to manifold atmospheric chamber is protected by HOLDING POSITIONvacuum, full power application is at- an air filter. The atmospheric cham- When the forward motion of thetained which is referred to as the ber is separated from the vacuum brake pedal is stopped and held, therun-out of the power unit. Any in- chamber by the bellows assembly valve operating rod ceases to movecrease in hydraulic pressure beyond within the vacuum chamber. the control valve plunger forward.this point must be supplied by phys- Vacuum is present at all times in However, the unbalanced forces ofical effort of the driver. that area of the vacuum chamber atmospheric pressure and vacuum on forward of the diaphragm. Vacuum each side of the diaphragm will con-NO POWER CONDITION is supplied through a hose from the tinue to move the outer sleeve of It should be noted that in case of intake manifold to the vacuum mani- the control valve plunger forwardengine failure and consequent loss fold and check valve on the booster keeping the vacuum porting closed.of engine vacuum, at least one full body. With this integral check valve At the same time, the reaction force
GROUP 2 - BRAKES and the hydraulic fluid, to return the master cylinder piston and push rod to the released positioned. With the piston and push rod in the released position, the hydraulic compensating port in the master cyl- inder is open. The open port per- mits fluid to either return from the brake system to the fluid reservoir, o r enter the brake system from the reservoir. PARKING B R A K E L M U S T A N G An independent hand-operated parking brake control actuates the rear wheel brake shoes through a cable linkage. The operating cable is routed from .the parking brake control assembly to the equalizer lever which is attached to the equal- izer assembly. The rear brake cables connect the equalizer assembly to the parking brake.lever at each rear sec- ondary shoe as shown in Figs. 1 and 2. When the hand1e.i~ pulled the pri- mary and secondary brake shoes are forced against the rear brake drums. The handle is held in the applied position by the engagement of a spring loaded pawl with a ratchet. Turning the handle counterclockwise disengages the pawl from the ratchet to release the brakes. PARKING BRAKE COMET, FAIRLANE AND FALCON An independent foot-operated parking brake control actuates theFIG. 10-Booster in Applied Position-Midland-Ross rear wheel brake shoes through a cable linkage. The operating cableacting through the reaction ring and valve closes off the bellows chamber is routed from the parking brakelever assembly will tend to move the from the hub porting that connects control assembly to the equalizer.atmospheric valve to the closed posi- to the rear side of the diaphragm. The rear brake cables connect thetion (Fig. 11). When these combined At the same time, the rearward equalizer assembly to the parkingforces balance, the porting to the movement of the plunger opens the brake lever at each rear secondaryvacuum supply will remain closed porting from the vacuum chamber shoe (Fig. 1).and the atmospheric valve will cut and draws out the air from the rear When the pedal is depressed theoff any further passage of atmos- side of the power diaphragm. With secondary brake shoes are forcedpheric pressure to ..the area behind vacuum on both sides of the dia- against the rear brake drums. Thethe diaphragm. Therefore, the power phragm, the assist force against the pedal is held in the applied,positionassist force acting on the master cyl- master cylinder push rod is elimi- by the engagement of a spring-loadedinder piston will stabilize and the nated. pawl with a ratchet in the controlhydraulic force applying the brakes Also, a pressure differential is cre- assembly (Fig. 29).will be maintained at a constant ated by the presence of vacuum on The parking brake control assem-level. the rear (small diameter) side of the bly is mounted to the cowl inner side valve hub and atmospheric (bellows) panel. The pedal pivots on a station-RELEASED POSITION pressure on the front (large diam- ary pedal mount. A spring-loaded When the pedal pressure is re- eter) side. This pressure differential pawl and a release lever are assem-leased from the valve operating rod moves the valve hub and, with it, bled to the pedal. A ratchet is as-and plunger assembly, the plunger the valve plunger and diaphragm as- sembled to the upper end of thereturn spring moves the plunger sembly back to the released position. pedal. The pawl contacts the rachetaway from the atmospheric valve This releasing action permits the at such an angle that the rachetallowing the valve to seat against the brake shoe retracting springs, acting teeth will slide over the pawl as thehub (Fig. 12). This seating of the through the wheel cylinder pistons pedal is depressed; however, when
PART 2-2 - BRAKE SYSTEM 2-15FIG. 1 1-Booster in Holding Position-Midland-Rossthe applying motion stops and the brakes in the applied position. tion of the lever on the pawl campedal starts to release, the pawl en- When the manual release lever is pin will disengage the pawl from thegages the ratchet and thus locks the pulled back, (Fig. 29), the cam ac- ratchet to release the brakes.
2-16 GROUP 2 -BRAKES FIG. 1 2-Booster in Released Position-Midland-Ross IN-CAR ADJUSTMENTS AND REPAIRS BRAKE SHOE ADJUSTMENTS move the drum and knock-out slug. The hydraulic service brakes are (Install a standard adjusting hole self-adjusting and require a manual cover in the carrier plate when as- adjustment only after the brake sembling). shoes have been relined, replaced, or When adjusting the rear brake when the length of the adjusting shoes, check the parking brake screw has been changed while per- cables for proper adjustment. Make forming some other service opera- sure that the equalizer operates tion. The manual adjustment is per- freely. formed with the drums removed, us- To adjust the brake shoes: ing the tool and the procedure de- 1. Using Rotunda Tool HRE tailed below. 8650, (Fig. 13) determine the inside In case a brake drum cannot be diameter of the drum braking sur- removed in the normal manner, an face. access knock-out slug is provided in 2. Reverse the tool as shown in Fig. 14 and adjust the brake shoe FIG. 13-Measuring Drum the brake carrier plate. Knock the slug out with a punch and then re- diameter to fit the gauge. Hold the ing screw, to prevent burring the lease the brake shoe as detailed automatic adjusting lever out of en- screw slots. Make sure the adjust- under Brake Drum-Removal. Re- gagement while rotating the adjust- ing screw rotates freely. If neces-
PART 2-2 - BRAKE SYSTEM hole in the carrier plate, and disen- gage the adjusting lever from the ad- justing screw. While holding the adjusting lever away from the adjust- ing screw, back off the adjusting screw with the brake adjusting tool (Fig. 15). Be very careful not to burr, chip or damage the notches in the adjusting screw; otherwise, the self-adjusting mechanism will not function properly. If the adjustment was backed off, make sure that the adjuster lever is properly seated in the shoe web. FIG. 14-Measuring Shoes sary, lubricate the adjusting screw 1. Remove the protective. coating threads with a thin, uniform coating FIG. 15-Backing Off Brake from a new drum with carburetor of Cl AZ-19590-B Grease. Adjustment degreaser. 3. Rotate Tool HRE 8650 2. Adjust the brakes as outlined around the brake shoes to be sure under Brake Shoe Adjustments in of the setting. 4. Pull the hub and drum assem- bly off the wheel spindle. this section. 4. Apply a small quantity of high 3. Place the drum over the brake temperature grease to the points assembly and into position. Install where the shoes contact the carrier INSTALLATION the three Tinnerman nuts and tighten plate, being careful not to get the 1 If the drum is being replaced, . them securely. Install the wheel on lubricant on the linings. remove the protective coating from the axle shaft flange studs against 5. Install the wheel on the drum the new drum with carburetor de- the drum, and tighten the attaching and tighten the mounting nuts to greaser. Install new bearings and nuts to specifications. specification. grease retainer. Soak the new grease 6. Complete the adjustment by retainer in light engine oil at least applying the brakes several times BRAKE SHOES AND 30 minutes before installation if re- ADJUSTING SCREW while backing the car. tainer is of a leather composition. 7. After the brake shoes have Rubber seals need not be treated REMOVAL been properly adjusted, check the with oil before installation. Pack the operation of the brakes by making 1. With the wheel and drum re- wheel bearings, install the inner bear- moved, install a clamp over the ends several stops while operating in a ing cone and roller assembly in the forward direction. of the wheel cylinder as shown in inner cup, and install the new grease Fig. 16. retainer. See Part 3-5, Section 4 for FRONT BRAKE DRUM procedure. If the original drum is being in- REMOVAL stalled, make sure that the grease in 1. Raise the car until the wheel the hub is clean and adequate. and tire clear the floor. Remove the 2. Adjust the brakes and install wheel cover or hub cap, and remove the drum assembly as outlined under "Brake Shoe Adjustments" in this the wheel and tire from the drum. section. 2. Remove the drum. If the drum 3. Install the outer wheel bearing, will not come off, knock the access washer and adjusting nut. slug out of the brake carrier plate, 4. Adjust the wheel bearing as using a punch. Insert a narrow outlined in Part 3-5,Section 2, then screwdriver through the slot and install the cotter pin grease cap. In- disengage the adjusting lever from the adjusting screw. While holding stall the wheel and hub cap. FIG. 16-Retracting Spring the adjusting lever away from the Removal-Typical screw, back off the adjusting screw REAR BRAKE DRUM with the brake adjusting tool (Fig. 2. Remove the brake retracting 15). Be very careful not to burr, REMOVAL springs using Tool 2035-N or chip, or damage the notches in the 1. Raise the car so that the wheel 2086-L (Fig. 16). adjusting screws; otherwise the self- is clear of the floor. 3 Disconnect the brake shoe hold- . adjusting mechanism will not func- 2. Remove the hub cap and down springs and remove the brake tion properly. wheel. Remove the three Tinnerman shoe assemblies along with the com- 3. Remove the grease cap from nuts and remove the brake drum. plete automatic adjustment mecha- the hub. Remove the cotter pin, nut 1f the drum will not come off, knock nism. lock, adjusting nut, and flat washer the excess slug out of the brake car- 4. Disassemble the brake shoes. from the spindle. Remove the outer rier plate, using a punch. Insert a 5. On rear brakes, remove the bearing cone and roller assembly. narrow screwdriver through the parking brake link and spring from
GROUP 2 -BRAKESthe brake assemblies. Disconnect 7. Apply a small amount of high- action of the adjuster by pulling thethe parking brake cable from the temperature grease to the threads section of the cable between theparking brake lever. and the socket end of the adjusting cable guide and the adjusting lever 6. After removing the rear brake screw. Turn the adjusting screw into toward the secondary shoe web farshoes disassemble the parking brake the adjusting pivot nut to the limit enough to lift the lever past a toothlever from the secondary shoe by re- of the threads and then back off /2 on the adjusting screw wheel. Themoving the retaining clip and spring turn. lever should snap into position be-washer (Fig., 1 and 2). Interchanging the brake shoe ad- hind the next tooth,, and release of justing screw assemblies from one the table should cause the adjuster side of the car to the other would spring to return the lever to its origi-INSTALLATION nal position. This return action of cause the brake shoes to retract 1. Before installing the rear brake rather than expand each time the the lever will turn the adjustingshoes, assemble the parking brake automatic adjusting mechanism op- screw one tooth.lever to the secondary shoe and se- erated. T o prevent accidental instal- If pulling the cable does-not pro-,cure it with the spring washer and lation of the adjusting screw on the duce the action described, or if theretaining clip. wrong side of the car the socket end lever action is sluggish instead of 2 Apply a light coating of high- . of the adjusting screw is stamped positive and sharp, check the posi-temperature grease at the points with an R or L (Fig. 18). The ad- tion of the lever on the adjustingwhere the brake shoes contact the screw toothed wheel. With the brakebacking plate. in a vertical position (anchor at the 3. Position the brake shoes on the top), the lever should contact thebacking plate and secure them with adjusting wheel 3/16 inch (plus or mi-the hold down springs. On the rear nus Ihz inch) above the centerlinebrake, install the parking brake link of the screw. If the contact point isand spring. Connect the parking below the centerline, the lever willbrake cable to the parking brake not lock oncthe teeth in the adjustinglever. . , screw wheel, and the screw will not Install the cable guide on the be turned as the lever is actuatedsecondary shoe web with the flanged ADJUSTING SCREW by the cable.hole properly fitted into the hole in IDENTIFICATION LINES To determine the cause of this H1143-Bthe secondary shoe web. Install the condition:secondary shoe to anchor spring a. Check the cable end fittings.(Figs. 1 and 2). FIG. 1 8--~djustin~ Screw and The cable should completely fill dr 5. Place the cable eye over the an- Lever ldentification extend slightly beyond the crimpedchor pin with the crimped side to- justing ,pivot nuts can be distin- section of the fittings. If it does notward the backing plate. Install the meet this specification, possible dam- guished by the number of groovesprimary shoe to anchor spring with age is indicated and the cable assem-the tool shown in Fig. 17. machined around the body of the nut. Two grooves indicate .a right- bly should be replaced. hand nut: one groove indicates a left- b. Check the cable length. The hand nut. cable should measure 83/16 inches on 8. Place the adjusting socket on 9 inch brakes or 10% inches on 10 the screw and install this assembly inch brakes from the end of the cable between the shoe ends with the ad- anchor to the end of the cable hook. justing screw toothed wheel nearest c. Check the cable guide for dam- the secondary shoe. age. The cable groove should be parallel to the shoe web, and the 9. Hook the cable hook into the body of the guide should lie flat hole in the adjusting lever. The ad- against the web. Replace the guide justing levers are stamped with an if it shows damage. R or L to indicate their installation on a right or left brake assembly d. Check the pivot hook on the (Fig. 18). lever. The hook surfaces should be square with the body of the lever 10. Position the hooked end of for proper pivoting. Replace theFIG. 17-Retracting Spring the adjuster spring completely into lever if the hook shows damage.Installation-Typical the large hole in the primary shoe web. The last coil of the spring e. See that the adjusting screw socket is properly seated in the notch 6. Thread the cable around the should be at the edge of the hole. in the shoe web.cable guide groove. Connect the loop end of the spring It is imperative that the cable be to the adjuster lever hole (Figs. 1 DISC BRAKE SHOE A N Dpositioned in this groove and not be- and 2). L I N I N G REPLACEMENTtween the guide and the shoe web. 1 . Pull the adjuster lever, cable 1 After any brake service work,Be certain that the cable eye is not and automatic adjuster spring down pump the brake pedal to obtain acocked or binding on the anchor pin and toward the rear to engage the firm pedal before moving the car.when installed. All parts should be pivot hook in the large hole in the Riding the brake pedal (common onflat on the anchor pin. Remove the secondary shoe web. left foot applications) should bebrake cylinder clamp. 12. After installation, check the avoided when driving the car.
PART 2-2 - BRAKE SYSTEM REMOVAL assembly on each side of the rotor hose should be checked for correct 1 Remove the wheel and tire . so that the lining faces the rotor. Be routing.from the hub and rotor assembly. sure that the tabs on the shoe flanges 4. Bleed the brake system as out-Be careful to avoid damage or in- seat fully against the caliper bridges lined in Section 2-1. Check the mas-terference with the caliper splash (Fig. 19). ter cylinder fluid level, and theshield, bleeder screw fitting or bans- 2. Install the caliper splash shield specified brake fluid as required.fer tube. and secure the shield to the caliper 5. Pump the brake pedal several 2. Remove the two bolts that with two retaining bolts (Fig 3). times to actuate the piston seals andattach the caliper splash shield, and 3. Pump the brake pedal several to position the shoe and lining as-remove the shield (Fig. 3). times .until a firm pedal is obtained semblies. 3. T o facilitate removal and in- and the shoe and lining assemblies 6. Install the wheel and tire.stallation of the shoe and lining are properly seated. 7. Road test the car.assemblies, the pistons must be 4. Install the wheel and tire onpushed into their bores. Apply a the hub and rotor assembly. FRONT WHEEL HUB A N Dsteady inward pressure against each 5. Check and refill the master ROTOR ASSEMBLY-DISCshoe and lining assembly toward its cylinder reservoir with specified BRAKESrespective caliper housing on each brake fluid as required.side of the rotor (Fig. 4). Maintain 6 . Road test the car. REMOVALthe pressure for at least a minute. It should not be necessary to bleedIf the pistons will not go in easily, the system after a shoe and lining 1 Remove the wheel and tire .force them in with water pump replacement. from the hub and rotor assemblypliers. (Fig. 20). Be careful to avoid dam- 4. Grasp the metal flange on the DISC BRAKE CALIPER age or interference with the caliperouter end of the shoe with two pairs ASSEMBLY splash shield, bleeder screw fitting orof pliers and pull the shoe out of the transfer tube.caliper (Fig. 19). REMOVAL 2. Remove the caliper assembly 1 Remove the wheel and tire . from the spindle and the rotor. If from the hub and rotor assembly. the caliper does not require servicing, Be careful to avoid damage or in- it is not necessary to disconnect the terference with the caliper splash brake hose or remove the caliper shield, bleeder screw fitting or trans- from the car. Position the caliper fer tube. out of the way, and support it with 2. Disconnect the front brake a wire to avoid damaging the caliper flexible hose from the brake tube at or stretching the hose. Insert a clean the bracket on the frame (Fig. 24). cardboard spacer between the linings 3. Remove the two bolts that to prevent the pistons from coming attach the caliper to the mounting out of the cylinder bores while the bracket. caliper is removed. Take care to avoid loosening the Handle the rotor and caliper as- bridge bolts that hold the two halves semblies in such a way as to avoid of the caliper together. deformation of the rotor and nicking 4. Lift the caliper assembly off or scratching of the brake linings. the rotor. 3. Remove the grease cap from the hub. Remove the cotter pin, nut INSTALLATION lock, adjusting nut, and flat washer 1 Position the caliper assembly . from the spindle. Remove the outer on the rotor, and mate the mounting bearing cone and roller assembly. bolt holes in the caliper with those 4. Remove the hub and rotor as- in the spindle. It may be necessary sembly from the spindle. to push the caliper pistons into the INSTALLATIONFIG. 19-Removing Disc Brake cylinder bores to obtain clearance 1. If the rotor is being replaced,Shoe and Lining Assembly- between the shoe and lining assem- remove the protective coating fromTypical blies and the rotor. The shoe and the new rotor with carburetor de- lining assemblies should be seated greaser. Pack a new set of bearings properly on the bridges. with specified grease, and install theCLEANING AND INSPECTION 2. Install the caliper to mounting inner bearing cone and roller assem- When the shoe and lining assem- bracket attaching bolts and torque bly in the inner cup. Pack greaseblies are replaced, remove the dust to specification. Check to insure that lightly between the lips of a newboots from the pistons. Check the the rotor runs squarely and centrally grease retainer and install the re-condition of the boots, and inspect between the two halves of the cali- tainer (Fig. 20).each piston surface for damage or per. There should be approximately If the original rotor is being in-corrosion. Thoroughly clean each 0.090-0.120 inch clearance between stalled, make sure that the grease indust boot and surrounding area be- the caliper and the rotor outside the hub is clean and adequate, thatfore installing. diameter (Fig. 4). the inner bearing and grease retainer 3. Connect the front wheel brake are lubricated and in good condition,INSTALLATION flexible hose to the brake tube at the and that the rotor braking surfaces 1 Position a new shoe and lining . bracket on the frame (Fig. 24). The are clean.