Caterpillar Cat 621F WHEEL SCRAPER (Prefix 9NL) Service Repair Manual Instant Download.pdf

Service Repair Manual
Models
621F WHEEL SCRAPER

Shutdown SIS
Previous Screen
Product: WHEEL SCRAPER
Model: 621F WHEEL SCRAPER 9NL
Configuration: 621F Wheel Tractor-Scraper 9NL00001-UP (MACHINE) POWERED BY 3406C Engine
Disassembly and Assembly
3406C DIESEL ENGINES FOR CATERPILLAR BUILT MACHINES
Media Number -SENR6409-02 Publication Date -01/07/2006 Date Updated -19/05/2015
SENR64090008
Governor
SMCS - 1264-016; 1264-015
Disassemble Governor
*Part of 6V4095 Pump and Governor Reconditioning Tool Group.
IN
Start By:
a. remove fuel injection pump housing and governor
b. remove fuel transfer pump
NOTE: If it is desired to only remove the governor so the fuel injection pump housing can be
disassembled, do only steps 1, 2, 3, 16, 22, 25, 26, 27, 28, 32, 34 and 37.
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https://127.0.0.1/sisweb/sisweb/techdoc/techdoc_print_page.jsp?returnurl=/sisweb/sisw...

1. Put the fuel injection pump housing and governor in position on Tool (A).
2. Remove the bolts, fuel ratio control (1) and shutoff solenoid (2) from rear governor housing (3).
3. Remove the bolts, rear governor housing (3) and the gasket from the front governor housing.
4. Remove governor spring (4), the two wave washers, one flat washer and the seat from the guide
in the rear governor housing.
5. Remove bolt (5) that holds lever assembly (6) to the shaft assembly.
NOTE: There is a key in the slot groove of the shaft assembly that must be removed before the
shaft assembly is removed from the rear governor housing.
6. Remove shaft assembly (7), lever (6) and lever (8) from the rear governor housing.
NOTE: Put an alignment mark on lever (9) for correct assembly purposes.
7. Remove bolt (10), lever assembly (9) and spring (11) from shaft assembly (7).
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8. Remove plug (12) and lip-type seal (13) from the housing.
NOTE: Spacers (14) and (16) are different sizes. Make sure they are assembled in the correct
position.
9. Use needle nose pliers, and remove the shaft. Remove spacer (14), lever (15) and spacer (16)
from the governor housing.
10. Remove two setscrews and locknuts (17) if necessary.
11. Release spring (18) from the notch in the housing. Remove snap ring (19), and remove shaft
(20) from the housing. Remove lever (21) and spring (18).
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12. Remove liptype seal (22) from the housing.
13. If necessary, remove the screws, cover (23) and the gasket from the governor housing.
14. Remove high idle cover (24) and three O-ring seals (25).
15. Remove liptype seal (26), dashpot valve (27), fitting (25), insulator and high idle adjustment
(28) from the rear housing.
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16. Remove two bolts (29), housing (30) and the gasket from the fuel pump housing.
17. Remove bolts (31), and remove torque control group (32) from the block.
NOTICE
Depending on the different engine applications, torque control groups
will vary. Inspect all parts for wear and damage, and make a note of
the correct sequence of the parts for assembly purposes.
NOTE: For additional information, see Specifications Manual SENR6470.
18. Remove the bolts and block (33) for the full load stop from the housing.
19. Remove the bolt that holds collar (35) to bolt (36).
20. Remove collar (35) and spring (34) from bolt (36). Remove bolt (36) from the block.
21. If necessary, remove the stop screw and the power setting screw from collar (35).
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NOTE: It may be necessary to turn the piston to remove the servo from the rack.
22. Remove the three bolts and governor servo (37) from the fuel injection pump housing.
23. Remove lockring (43), seat (42), spring (41) and sleeve (40) from valve (39). Remove lockring
(38) from the groove in the center of valve (39).
24. Remove sleeve (44), valve (45) and piston (46) from the governor servo. Remove O-ring seal
(50) from sleeve (44). Do not remove pin (47). If pin (47) and lever (48) or cylinder (49) are worn
or damaged replace the assembly.
25. Use Tool (C) to hold spring (51) under compression so the ring on the governor shaft can be
removed.
26. Remove the ring, and carefully remove Tool (C).
27. Remove bearing (52), the sleeve and spring (51) from the governor shaft.
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28. Remove ring (53) and dashpot assembly (54) from the governor shaft.
29. Use Tool (B), and remove ring (60) from seat (57).
30. Remove ring (59) and spool (58) from seat (57).
31. Remove seat (57), and spring (56) from shield (55).
32. Remove spring (62), if equipped, and riser (61) from the governor shaft.
33. Remove ring (63), races (64) and bearing (65) from the riser.
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34. Remove the bolts and carrier assembly (66) from the fuel injection pump housing.
35. Remove dowels (68) and flyweights (69) from the carrier assembly.
36. Remove dowel (67) from the governor shaft, and remove the governor shaft from the carrier
assembly.
37. Remove races (70) and (72) and bearing (71) from the camshaft in the fuel injection pump
housing.
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Assemble Governor
*Pump and Governor Reconditioning Tool Group
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1. Put the fuel injection pump housing in position on Tool (A). Install race (3), bearing (2) and
race (1) on the end of the camshaft in the fuel injection pump housing.
2. Put flyweights (5) in position on carrier assembly (4), and install dowels (6) to hold the
flyweights in place. The flyweights must move freely on the dowels and have 0.010 to 0.230 mm
(.0004 to .0090 in) end play.
3. Install governor shaft (7) on carrier assembly (4).
4. Install dowel (8) in governor shaft (7), and slide carrier assembly (4) down on the governor
shaft until dowel (8) fits into the slot in the carrier assembly.
5. Install carrier assembly (4) on the end of the camshaft.
6. Install race (12), bearing (11), race (10) and ring (9) on riser (13).
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7. Install riser (13) and spring (14), if equipped, on the governor shaft.
8. Install spool (18) and ring (19) on seat (17), and use Tool (B) to install ring (20) to hold them in
position.
9. Install seat (17) on spring (16) and spring (16) on shield (15).
10. Install dashpot assembly (21) on the governor shaft.
11. Install ring (22) in the groove on the governor shaft. Install sleeve (23), spring (25), the sleeve
and bearing (24) on the governor shaft.
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12. Use Tool (C) to hold spring (25) under compression, and install the ring in the groove on the
governor shaft.
13. Install O-ring seal (26) on sleeve (27). Install piston (29) and sleeve (27) in the governor servo
as shown.
14. Install valve (28) in the governor servo as shown.
15. Install lockring (33) in the groove near the center of valve (28). Put sleeve (34), spring broken
link spring (35) and seat (36) in position on valve (28), and install lockring (37) to hold them in
place.
16. Put governor servo (30) in position on the fuel injection pump housing with piston (29)
engaged over the rack. Make sure the lever is engaged in the slot groove of riser (13).
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17. If dowel (43) was removed, install it in block (44) 31 ± 0.5 mm (1.22 ± .02 in) above the
outside surface of the block.
18. Install bolt (45) in block (44) and spring (38) on bolt (45).
19. Install stop screw (40) and the locknut on collar (42). Install power setting screw (41) and the
locknut on the collar.
20. Install collar (42) on bolt (45). Make an alignment of the hole in the collar with the notch in
bolt (45), and install bolt (39).
21. If the dowels that align block (44) with the front governor housing were removed, install them
4.0 ± 0.5 mm (.16 ± .02 in) above the outside surface of the front governor housing.
22. Put block (44) in position on the front governor housing with the holes in the block in
alignment with dowels in the front governor housing.
23. Install dowels (46) in the front governor housing 6.0 ± 0.5 mm (.24 ± .02 in) above the outside
surface of the front governor housing.
24. Assemble torque spring group (47) in the correct sequence, and install it on the block.
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To avoid possible personal injury and damage to the engine when front
governor housing (48) is installed on the fuel injection pump housing,
make sure the flange on bolt (45) is behind the shield of the dashpot. If
the flange on the bolt is installed on the wrong side of the shield, the
riser in the governor will be held in the maximum fuel delivery position.
25. Install the gasket and front governor housing (48) on the fuel injection pump housing. Make
sure the flange on bolt (45) is behind the shield of dashpot (21).
26. Check the seal on dashpot valve (51) for damage or wear, and make a replacement if
necessary.
27. Install dashpot valve (51), insulator (49), fitting (50) high idle screw (52) and the locknut in
rear governor housing (53). Tighten insulator (49) to a torque of 4.5 ± 0.5 N·m (40 ± 4.4 lb in).
28. Use Tool (D), and install seal (54) with the lip of the seal down as shown. Put clean engine oil
on the lip of the seal. Install high idle screw cover (55) and O-ring seal (56).
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29. Install the liptype seals in housing (53) with Tool (D) as shown.
30. Install the gasket and cover (57) in the governor housing.
31. Put clip (60) in position on shaft (61), and install shaft (61) into the housing through spring
(59) and lever (58). Put the key in the lever in alignment with the keyway in the shaft.
32. Install clip (62) on the shaft, and install screw (63) and the locknut on the lever. Put the end of
the spring in position in the notch in the housing as shown.
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33. Install screws (64) and locknuts (65) on lever assembly (66). Tighten locknuts (65) to a torque
of 1.70 ± 0.25 N·m (15 ± 3 lb in).
34. Install shaft (68) in the housing. Install long spacer (67), lever assembly (66) and the short
spacer on shaft (68).
35. Check the condition of the O-ring seal on the plug. Lubricate the O-ring seal with clean engine
oil, and install the plug to hold shaft (68) in position.
36. Install lever assembly (72) on shaft assembly (73). Be sure the alignment marks on the
components are in alignment with each other.
37. Install shaft assembly (73) into the housing. Put washer (71) and lever (74) in position on the
shaft assembly. Put key (70) in the key slot on shaft assembly (73), and install lever (69) over the
key on the shaft assembly. Align the bolt hole in lever (69) with groove (75) in the shaft assembly,
and install the bolt.
38. Install seat (76), wave washer (78), washer (79), wave washer (80) and spring (81) on guide
(77).
To avoid possible personal injury and damage to the engine when rear
governor housing (53) in installed on the fuel injection pump housing,
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make sure the flyweights are toward the fuel injection pump housing. If
the flyweights are extended out too far, the riser in the governor will be
held in the maximum fuel delivery position.
39. Install gasket (82) and rear governor housing (53) on the front governor housing.
40. Make the governor adjustments. See the topic "Fuel Ratio Control & Governor Check" in the
System Operation Testing & Adjusting Manual, Form No. SENR6471.
41. Put fuel ratio control (83) in position. Make sure the flange on the end of the fuel ratio control
is behind the slot in lever assembly (66). See Illustration B88652P1.
42. Hold the control lever in the fuel off position, and install shutoff solenoid (84).
43. Make an adjustment to the fuel ratio control. See the topic "Fuel Ratio Control And Governor
Check" in the System Operation Testing & Adjusting Manual, Form No. SENR6471.
End By:
a. install fuel transfer pump
b. install fuel injection pump housing and governor
Fri Mar 19 17:13:06 UTC+0800 2021
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Shutdown SIS
Previous Screen
SENR64090009
Fuel Injection Pumps
SMCS - 1251-012; 1251-017; 1251-011
Remove Fuel Injection Pumps
Start By:
a. remove fuel injection lines
1. Remove the plug, and move the race until Tool (A) can be installed to hold the rack in the center
position. The rack must be in the center position to remove the fuel injection pumps.
To prevent possible personal injury carefully follow the steps below.
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2. Put Tool (B), except for the 8T5287 Wrench, in position on the fuel pump housing as shown.
Lower the handle to center the adjusting screw with the fuel line seat. With the handle down in the
locked position, the adjusting screw must just be in contact with fuel line seat (1). If force is needed
to lower the handle or there is a gap, remove the tooling, and make an adjustment to the screw.
3. Loosen bushing (2) 1/4 of a turn.
4. Put Tool (B) in position on the pump housing with the handle down in the locked position as
shown.
5. Remove bushing (2) from the pump housing.
6. Carefully and slowly lift the handle to release the spring force. Remove the tooling.
7. Install Tool (C) on fuel pump (4) as shown.
8. Remove seal (3) and fuel pump (4) from the fuel pump housing.
9. Remove spacers (5) from the pump housing.
NOTE: There must be a pump installed on either side of the pump to be removed to install Tool (B).
If there is no pump, take a pump already removed, and remove the spring so there will be no spring
force, and install it in the pump housing. See Install Fuel Pump.
NOTE: Spacers (5) are the same thickness for each fuel injection pump so they can be mixed. The
fuel injection pump plungers and barrels are sets and cannot be mixed.
Install Fuel Injection Pumps
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1. Install spacers (5) in the fuel pump housing.
2. Move the rack until Tool (A) can be installed to hold the rack in the center position. The rack
must be in the center position to install the fuel injection pumps.
3. Install a fuel pump without its spring so that Tool (B) can be installed. See Step 5 for correct fuel
pump installation.
4. Install Tool (C) on the bonnet of the fuel pump as shown.
5. Install the fuel pump in the pump housing with the saw cut (slot) (9) in the gear in alignment with
small pin (6) in the lifter assembly and groove (8) in the barrel in alignment with large pin (7) in the
pump housing.
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6. Install the seal and bushing (2) on the fuel pump.
7. Put Tool (B) in position on the fuel pump housing as shown.
8. Lower the handle slowly and carefully. If the fuel pump is not installed correctly, the handle will
not go all the way down. Do not try to use force on it. Remove and install the tooling and the fuel
pump again.
9. Make sure the seal is in its correct position, and start to tighten bushing (2). Remove the tooling,
and tighten the bushing to a torque of 260 ± 15 N·m (190 ± 10 lb ft). Back off 180 degrees and
tighten the bushing again to a torque of 260 ± 15 N·m (190 ± 10 lb ft).
Typical Example
10. After each fuel pump has been installed, follow the steps below to check total race travel to
make sure each pump has been installed correctly.
a. Install Tool (D) on the fuel pump housing as shown and zero the dial indicator.
b. Remove Tool (A) from the fuel pump housing.
c. Move rack (10) in and out of the fuel pump housing to measure rack travel. Rack travel is
approximately 9.62 mm (.379 in) in the plus (full fuel) direction and 10.40 mm (.410 in) in the
minus (shutoff) direction. If this measurement is not obtained, center the rack, install Tool (A), and
remove and install the fuel pump again.
NOTE: One tooth off and rack travel is approximately 6.35 to 6.82 mm (.250 to .269 in) in the plus
direction and 7.02 to 7.05 mm (.276 to .278 in) in the minus direction.
End By:
a. install fuel injection lines
Disassemble & Assemble Fuel Injection Pumps
See SMHS8378 for the correct tool usage.
Start By:
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a. remove fuel injection pumps
NOTICE
Be careful when the injection pumps are disassembled. Do not damage
the surfaces of the plungers, barrels and bonnets. Any scratches will
cause leakage inside the fuel injection pump. The plunger and barrel
for each pump are made as a set. Do not put the plunger of one pump
in the barrel of another pump. If one part has wear, install a complete
new pump assembly. Be careful when the plunger is put into the bore
of the barrel.
NOTE: Do not remove the gear from the plunger. The gear and plunger are assembled and adjusted
at the factory.
1. Pull plunger (4) and washer (3) out of barrel (1) and spring (2).
2. Remove spring (2) from barrel (1).
3. Use the following procedure to put the fuel pump in position on Tool (A):
a. Select the correct turret position.
b. Place a barrel assembly into the turret.
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c. Loosen the nut on the clamp.
d. Adjust clamp end (6) until the bonnet is almost touching the barrel when the clamp handle is in
the locked position.
e. Tighten the nut on the clamp.
4. Use Tool (B) to expand ring (5), and carefully lift it off the fuel pump.
5. Slowly release the clamp handle of Tool (A), and remove the lockring.
6. Remove bonnet (7), spring (8) and valve (9) from barrel (1).
NOTE: The following steps are for assembly of the fuel injection pumps.
NOTICE
Put clean fuel on all parts during assembly.
7. Put spring (8) and valve (9) in bonnet (7).
8. Put bonnet (7) barrel (1) and ring (5) in position on Tool (A).
9. Put the barrel assembly in position on Tool (A). Lower the handle on Tool group (A) to hold the
fuel pump together.
10. Use Tool (B), and lower ring (5) on to the barrel and the bonnet to hold them together.
11. Remove the barrel assembly from Tool (B).
12. Install spring (2) on barrel (1).
13. Install washer (3) on plunger (4). Make sure the spring seat on the washer is away from the gear
on the plunger.
14. Install plunger (4) in barrel (1). Make sure spring (2) is engaged in the spring seat on washer (3).
End By:
a. install fuel injection pumps
Copyright 1993 - 2021 Caterpillar Inc.
All Rights Reserved.
Private Network For SIS Licensees.
Fri Mar 19 17:14:01 UTC+0800 2021
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Shutdown SIS
Previous Screen
SENR64090010
Fuel Injection Pump Housing
SMCS - 1253-015; 1253-016
Disassemble Fuel Injection Pump Housing
Start By:
a. disassemble governor
b. remove fuel injection pumps
1. Remove the six lifters from the fuel pump housing.
2. Remove rack (1) and camshaft (2) from the fuel pump housing. If necessary, use a soft hammer
to push the camshaft out the governor end.
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3. Use Tool (A) and remove the three camshaft bearings from the fuel pump housing.
4. Remove rack bearing (4) and the other rack bearing from the fuel pump housing.
5. Remove dowel (3) from the fuel pump housing.
6. Remove bolts (6), cover (5) and the gasket from the fuel pump housing.
Assemble Fuel Injection Pump Housing
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1. Install gasket (7) and cover (5) on the side of the fuel pump housing.
2. Use Tool (B) and install the D shaped rack bearing into the governor and fuel pump drive side
of the fuel pump housing 87.0 ± 0.5 mm (3.42 ± .02 in) from outside surface (X).
3. The inside flat diameter after assembly must be 11.178 ± 0.050 mm (.440 ± .002 in) and the
inside large diameter must be 12.767 ± 0.058 mm (.503 ± .002 in).
4. Install dowel (3) in the fuel pump housing 6.0 ± 0.5 (.24 ± .02 in) above the outside surface.
5. Use Tool (C) and install the rack bearing into the fuel pump housing 7.16 ± 0.13 mm (.282
± .005 in) below the surface of the pump housing.
6. The inside diameter of the bearing after assembly must be 12.746 ± 0.045 (.502 ± .002 in).
7. Use Tool (A) and install the three camshaft bearings in the fuel pump housing with the oil holes
in the bearings 30 ± 3 degrees from the horizontal center line toward the plugged holes in the fuel
pump housing.
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8. The inside diameter of all three bearings after assembly must be 68.399 ± 0.038 mm (2.6905
± .0015 in).
9. Make sure bearing (8) on the governor and fuel pump drive is installed 1.0 ± 0.5 mm (.04 ± .02
in) below surface (Y).
10. Make sure middle bearing (9) is 218 ± 0.3 mm (8.6 ± .01 in) below surface (Y).
11. Make sure bearing (10) governor side is 1.00 ± 0.25 mm (.040 ± .010 in) below the outside
surface.
12. Remove the plugs from the side of the fuel pump housing. The oil holes in the bearings must
in alignment with holes (11) in the fuel pump housing. If the bearings are not in alignment,
remove them and install again.
13. Make an alignment of rack (1) and install it in the fuel pump housing.
14. Install the six lifters in the fuel pump housing. Make sure the pins in the lifter are on the same
side as the dowels in the fuel pump housing.
End By:
a. install fuel injection pumps
b. assemble governor
Fri Mar 19 17:14:57 UTC+0800 2021
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Shutdown SIS
Previous Screen
SENR64090011
Fuel Ratio Control
SMCS - 1278-010; 1278-017
Remove & Install Fuel Ration Control
1. Disconnect air line (1) from the fuel ratio control.
2. Remove wire seal (4) from the bolts.
3. Remove bolts (3) that hold fuel ratio control (2).
4. Remove the fuel ratio control by pulling down and out from the collar.
NOTE: The following steps are for the installation of the fuel ratio control.
5. Put fuel ratio control (2) in position on the governor. Make sure the valve head of the fuel ratio
control is connected in the groove of the collar.
6. Install bolts (3) that hold the fuel ratio control to the governor. Connect air line (1) to the fuel ratio
control.
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Suggest:
If the above button click is invalid.
Please download this document
first, and then click the above link
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7. To make an adjustment to the fuel ratio control, see the topic "Governor Adjustment For The Air
Fuel Ratio Control" in, Testing & Adjusting Manual SENR6471.
8. Install wire seal (4) on the bolts with Tool (A).
Disassemble & Assemble Fuel Ratio Control
Start By:
a. remove fuel ratio control
1. Put Tool (A) in a vise so that the station being used is not over the vise jaw. Place the fuel ratio
control over the pins in Tool (A). Remove bolts (3) and remove cover (26) and gasket (24).
NOTICE
There is spring force behind cover (7). Hold cover (7) in position, and
slowly remove the bolts that hold it to release the spring force.
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Caterpillar Cat 621F WHEEL SCRAPER (Prefix 9NL) Service Repair Manual Instant Download.pdf

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