With no service interval in the owner manual, customers question why the technician recommended a brake fluid change.
Each of these reasons will be covered in the up coming slides
It is very important to do a good flush. This means getting all of the old fluid out. 1 minute drain at each wheel allowing enough brake fluid to pass through the system.
What ISBRAKE FLUID?
Polyethylene Glycol Based (Not Oil Based) PEG Products Laxatives, Eye Drops, Skin Creams Tooth Paste, Printer Ink Solvent Spandex, Foam Cushions, Paint Ball FillAll Start life as ethylene glycol--ANTIFREEZE
MAP was created to protect the interests of AutoRepair Industry Vehicle OwnersMAP’s mission is to insure consistency ininspections of vehicles and communication ofthat inspection to the customer.
Uniform Inspection and Communication Standards.Shops needed uniformity in repairrecommendationsCustomers needed more informationto make an educated decision
MAP BRAKE FLUID TASK COMMITTEEWHY CHANGE BRAKE FLUID? Some say every 24,000 miles Others say every 36 months It’s Hygroscopic and absorbs moisture Technicians say replace if color is dark Its just a good thing to do (very unscientific) WHAT’s RIGHT???
Information Sources National Institute of Standards and Technology NIST , Ricker, R.E., Fink, J.L., Shapiro, L.C., and Schaefer, R.J., Preliminary Investigation Into Corrosion in Anti-Lock Braking Systems SAE International Congress & Exposition, SAE Intl Jackson, G.L., Levesque, R. and Wagner, F.T., Improved Methods for Testing the Durability of Corrosion Protection in Brake Fluids. National Highway Traffic Safety Administration NHTSA Person, G.H., Boyd, R., Demeter, K., Tests on Kelsey Hayes EBC4 Antilock Brake Systems, Vehicle Research and Test Center The Institute of Mechanical Engineers Jacobson, M.A., Corrosion of Motor Vehicles: Safety and Environmental Factors: The User’s View, Corrosion of Motor Vehicles. FMVSS 116 Motor Vehicle Brake Fluids Code of Federal Regulations , Title 49- Transportation, Chapter V-National Highway traffic Safety Administration (DOT), Part 571-Federal Motor Vehicle Safety Standards, B. Swidal Ed, Office of Federal Register, Washington, DC, 1995, 6. Anon., in SAE Handbook, SAE International. NY, 1995
Brake Fluid DOT Standard FVMSS116TESTS INCLUDE: Wet and Dry Boiling Point Corrosion Other tests Viscosities, evaporation, effect on rubber
HygroScopic Absorbs moisturemoIsture lowers the boiling point
Wet & Dry Boiling Point STANDARD 116 DRY BOIL WET BOIL add 3.7% waterPEG DOT 3 401F 284FPEG DOT 4 446F 311FSilicone DOT 5 500F 356FPEG DOT 5.1 518F 374F DOT 4 & 5.1 Borate Esters are added to raise the boiling point.
Brake Fluid Boiling Point• Very rare today (Private studies)• OE Fluids have higher boiling points• System design changesSAE 2001-01-0947Hoses with rubber inner layers did not resistmoisture as well as today’s hoses with EPDMinner layers.
MAP as of 11/01/2003 While moisture is an issue with brake fluids The measurement of moisture that is detrimental to brake fluid performance has not been found. In addition No specification exists for an in-use brake fluid boiling point. Therefore no recommendation for replacement based on moisture content can be made with confidence.
Color Does NOT Prove Contamination New fluid specification is colorless to amber. Dye from seals and hoses may cause the brake fluid to turn a darker color. New vehicles have been found to have dark fluid even before being driven.
O.E.M. Service Intervals GM FORD CHRYSLER Do NOT have SERVICE INTERVALS Most Imports service interval is 24 to 36 months / 1000 miles
Corrosion InhibitorsBuffering Amines Reduces the acid levelFilming Amines Protective film on metalsNote: Flush brake fluid when replacing calipers.
2 Functions of BRAKE FLUID1. Apply hydraulic pressure to brake components to slow the vehicle2. Protect the Brake System from CORROSION
Copper Is the first metal to corrode Direct relationship to depleted corrosion inhibitors
Office of Defect Investigation (ODI)National Institute of Standards and Technology (NIST) to study ABS MODULES
ABS and CorrosionNIST STUDYABS systems have increased brake fluid mixing results in the corrosion inhibitor concentration decreasing faster.ABS systems use close tolerance valves that must operate quickly and more concisely than conventional braking systems.ABS systems are more susceptible to degradation in performance due to corrosion or deposits.”
Braking ProblemNHTSA investigated sudden increasedpedal travel due to a leak in the modulatordump valve. Their findings of the cause ofvalve leakage was “very small particles ofpure copper present in the area of thevalves dump seat and sealing surfaces.”
Copper Is…. Early Warning for iron corrosion Indicator of lossed buffering capability Causes iron to corrode rapidlySAE, Jackson, “After 30 months of service copper reached 200ppm”.NIST, Ricker, “The hypothesis that the large surface area of copper inthe brake lines corrodes slowly during normal service resulting in theaccumulation of copper ions in the brake fluid that can be transported toother parts of the braking system and cause corrosion of ferrous alloys,once the corrosion inhibitors become depleted”.
Copper vs Iron400350300250 Copper200 Iron15010050 0 0 10 20 30 40 50 60 70 80 90 100 110 MonthsTABLE 1. Copper and iron levels versus the age of brake fluid. Each pair ofiron/copper symbols represents a single vehicle
Component : Brake Fluid At or beyond OEM service interval Suggest service Brake fluid type incorrect Require flushing Contaminated Require flushing Corrosion inhibitors depleted Require flushing A copper content of 200 ppm or greater indicates a depletion of corrosion inhibitors in the brake fluid Hydraulic component overhaul or replacement Suggest flushing
TEST Don’t Guess Gives the customer confidence Attach the BrakeStrip to the repair order making an informed customer Increase brake fluid flush sales Use BrakeStrip on every inspection
Reasons to suggest a Brake Flush: Beyond service interval (There are NO service intervals for domestic OE!) Brake fluid type incorrect Contaminated with moisture (RARE and hard to prove Contaminated with oil (Spongy rubber parts) Contaminated with corrosion (Copper)
Brake Fluid FlushingPRESSURE IS THE BEST METHOD1 Apply brakes a few times to suspend contaminants in brake fluid.2 Remove old brake fluid and contaminants from reservoir.3 Add new brake fluid to reservoir.4 Hold down brake pedal 1 inch to allow fluid to escape from master cylinder chamber.5 Perform OE bleeding instruction including correct sequence.6 Use at least 1 quart to ½ gallon of new brake fluid to pass through system. (1 minute flow at each bleeder).
Testimonials “The test strips are great and most of our brake flushes come from the test strips. The guys love to use them and it makes them extra money. “The brake flush strips have increased flush system sales 70% at our location over the previous year.” “Test strips work great and increase the trust factor in the relationships with my customers.”
Brake Flush Profit Price of the Service $70.00 Quart Brake Fluid -$5.00 Technician’s labor -$15.00 Profit $50.00
How many can you do in a Month? 10 20 30 Services?
Do What’s Right Make sure everyone in your shop is on the same page. TEST for COPPER