Brake Fluid Exchange

Transcription

1 Brake Fluid Exchange OJT / Practice DTOG Proficiency Exam Date: Trainee: Trainer: Service Center: Brake Fluid Exchange 1. Prepare for service Wear proper Personal Protective Equipment Recommended PPE: Safety glasses with side shields or goggles Nitrile gloves for most of service / Work gloves when using air impact wrench Dark colored work shoes with slipresistant soles and oil-resistant uppers Bump hat when working under vehicle Do NOT wear: Loose hanging objects (necklaces, bracelets) Loose clothes (shirt not tucked) Prepare tools Brake bleeding equipment Auto-refill kit and adapters for cap Brake bleeder wrenches Penetrating oil Shop towels, brake cleaner fluid, and water to clean spill of brake fluid Torque wrench for lug nuts DTOG Brake Fluid Exchange 1

2 1. Prepare for service (continued) Identify vehicle manufacturer specifications for brake fluid and service procedures Use POS, ALLDATA or authoritative source Type of brake fluid Volume of brake fluid Default: 1 quart for average passenger car Proper torque for lug nuts Sequence in which to bleed brakes Default: begin at farthest from master cylinder and work towards closest Proper torque for lug nuts 2. Prepare the vehicle Ask customer how their brakes are working Identify anything that could cause trouble during test drive Gather information about problems Test drive vehicle Develop road test course that allows acceleration, braking, right turns, left turns Test for brake noise, brake pulsation, pulling when braking, pulling when not braking Note pedal condition and unusual conditions including unusual noises associated with stopping the vehicle such as grinding or squealing. Test parking brake operation Check for drivability concerns Engine miss, sputter Check suspension, pulling, noise (tires, wheel bearings) Check engine, warning lights Listen for any unusual noises, etc DTOG Brake Fluid Exchange 2

3 2. Prepare the vehicle (continued) Drive vehicle into bay Call/Response Specialist: Car coming in, Bay # LBT: Thank you, Bay # Raise hood, install fender covers 3. Inspect the brake system Record the brake fluid level Record brake fluid level upon arrival (so that it can be reset to this level upon conclusion of the Exchange service) Note: Not necessary if the brakes are being replaced. Inspect master cylinder Check seals for swelling and potential contamination Lift vehicle / Remove all 4 wheels Follow appropriate procedures for lifting a vehicle Call/Response Specialist: Clear to raise lift, Bay #? LBT: Clear to raise lift, Bay # Specialist: Raising lift, Bay #. LBT: Thank you, Bay # Specialist: Lift is locked, Bay #? LBT: Thank you, Bay # DTOG Brake Fluid Exchange 3

4 3. Inspect the brake system (continued) Inspect hydraulic lines Inspect from master cylinder to brake calipers / wheel cylinders Look for leaks or signs of leakage Look for kinks, cracking, crimping, dents, excessive deterioration/corrosion, or abrasion Inspect brake hoses for signs of fraying and excessive deterioration Note: Do not flex rubber components during inspection Visually inspect pads / shoes Disc brake pads should be at least as thick as the backing plate Use feeler or tread depth gauge to verify that drum shoes are at least 2/32 thick If brake pads and shoes are below minimum standards for a visual inspection, recommend a complete brake inspection to the customer Crack bleeder valves Spray with penetrating oil to loosen rust Clean area around bleeder valve to prevent contaminants from entering brake hydraulic system Remove bleeder valve rubber boot Don't try to open frozen bleeder because they could snap off If any bleeder valves cannot be opened, bring this to customer's attention before continuing service Note: Service should not be continued unless the caliper or the wheel is replaced as appropriate. Close bleeder valve DTOG Brake Fluid Exchange 4

5 3. Inspect the brake system (continued) If necessary, note inspection results on the invoice If brake pad or shoe thickness is r below minimum standards, the results must be discussed with the customer before you can continue with the service 4. Evacuate brake fluid from master cylinder Clean area around master cylinder cover Use shop towel and brake cleaner fluid Prevent dirt/debris from falling into Remove cover and screen If cover has gasket, remove gasket with cover Remove screen if equipped Attach vacuum pump to air supply Evacuate fluid from Remove as much fluid as possible from Leave a little fluid to prevent air from entering master cylinder Remove as much sediment from bottom of as possible Immediately clean any spills of brake fluid Use rags when removing hoses from Use water to clean painted surfaces DTOG Brake Fluid Exchange 5

6 5. Install automatic fluid refill system Verify adapter on auto-refill system fits Install brake fluid delivery system to Adaptors are available for pints, quarts and ½ gallon containers Use a fresh bottle of brake fluid specified by vehicle manufacturer Open valve to allow brake fluid to flow Adjust height to keep filled Normally set at Max line Do not allow brake fluid to drain out of during service 6. Exchange brake fluid at each wheel Follow recommended sequence Follow vehicle manufacturer recommended sequence for which wheels to bleed first This information can typically be found in ALLDATA under Brake Bleeding Attach bleeder valve wrench to valve Connect vacuum hose to bleeder valve If the hose does not seal securely, hold the hose with fingers to maintain tight fit If you need to create a better seal, use teflon tape or a silicone-based grease around the threads of the bleeder Turn vacuum pump on Open bleeder valve to allow fluid to flow Use bleeder valve wrench Allow enough fluid to flow to assure that fluid between master cylinder and wheel has been exchanged Check amount of fluid evacuated in of suction equipment May be able to see difference in fluid when new fluid emerges Close valve and remove suction hose Use bleeder valve wrench to close valve DTOG Brake Fluid Exchange 6

7 6. Exchange brake fluid at each wheel (continued) Turn off vacuum pump Replace bleeder valve cap Verify fluid in master cylinder is at originally recorded level If necessary, empty canister from vacuum machine Proceed to next wheel in sequence and repeat process Reset fluid level to that notated at the start of the exchange (only if no brake service is performed) Explain to customer why fluid was set to this level JL uses the fluid level as an indicator for determining brake wear Follow local regulations for disposal of used brake fluid As you get closer to master cylinder, the need to bleed less brake fluid may result 7. Remove automatic refill system Close valve on auto-refill system Remove auto-refill system from Use rags when removing hoses from to avoid drips Immediately clean any spills of brake fluid Adjust fluid in master cylinder to originally recorded level Adjust fluid level to that notated at the start of the exchange (only if no brake service is performed) If not adjusted to Max line, explain to customer why fluid was set to this level JL uses the fluid level as an indicator for determining brake wear Reinstall master cylinder cap DTOG Brake Fluid Exchange 7

8 8. Test brakes Pump brake pedal to determine that it feels the same as it did upon arrival Turn ignition to the RUN position and check for red and amber brake lights illuminations Pedal usually goes to the floor on first pump, but should become firm after several pumps Check for leaks around master cylinder Check for brake fluid leaks at each wheel Check for leaks around bleeder valves Use flashlight to make sure bleeder is dry Check for fluid on rotors Clean rotors with brake clean spray and shop towels Reinstall wheels Perform quality inspection of lug nuts Second technician checks torque on all lug nuts Lower vehicle Follow appropriate procedures for lowering a vehicle Call/Response Specialist: Clear to lower lift, Bay #? LBT: Clear to lower lift, Bay # Specialist: Lowering lift, Bay #. LBT: Thank you, Bay # Remove fender covers and lower hood Test drive vehicle Follow previous procedures for test drive If the amber ABS light illuminates, it should extinguish after a few seconds If it doesn't extinguish, a Diagnostic Trouble Code (DTC) will need to be retrieved from the ABS control module and diagnosed DTOG Brake Fluid Exchange 8

9 9. Complete service Dispose of used brake fluid according to applicable laws and regulations DTOG Brake Fluid Exchange 9