Automobile Braking System Fault Diagnosis and Troubleshooting

• • Automatic braking system of judging and elimination of

Failure:
(1) motor cars and the use of brake, the car can not slow down or stop
(2) the use of one or more brake, the brake suddenly does not work
1, first of all, observe whether the pressure barometer instructions to check whether the compressed gas storage barrel. Barometer instruction is zero, no compressed gas storage barrel. Check the status of the press belt, if belt fracture, should be replaced; if belt slippage, should adjust its tightness. Removed the press out of the trachea, starting the engine, check the air pressure conditions, if the compressor does not push gas compressor valve seal shows bad or broken springs, and loose pressure valve failure, should be replaced. If the compressor pressure gas well, check the pipeline between the pump and the reservoir is leaking, if the trachea loose joints leak, should tighten. If the tracheal rupture, should welding repair or replacement. Such as the barometer instruction is zero, gas storage cylinder with compressed air, indicating to the brake reservoir pump pipeline leaks and should overhaul. Such as the barometer directed normal, gas storage cylinder with compressed air, indicating failure in the brake control device.
2, if the above examinations are normal, check the brake pedal and the brake arm is pulled out of line, if out of line should be re-installed.
3, depresses the brake pedal test
(1) barometer reading is low or falling down. Check brake pedal free travel, if the free path is too large, indicating brake not open the inlet valve should be adjusted. Check brake pull arm activities, if the pull arm does not move, indicating brake stuck putting should be dismantled maintenance reasons. (2) The falling barometer reading, and there is sound leakage. ① Check brake valve is leaking, if the leak shows that brake diaphragm rupture, should be replaced. ② check the brake to the brake pipe is leaking gas chamber, if the leak shows that brake diaphragm rupture, should be replaced. ③ check the brake to the brake pipe is leaking gas chamber, if the leak shows that brake chamber diaphragm rupture, should be replaced.
4, raised his brake pedal to check brake is leaking, if the leak shows that brake into the valve seat Mifengbuyan or card should be replaced.
5, after the above-mentioned examinations are normal, depresses the brake pedal, if the barometer readings drop to normal, should be demolished seized the wheel brakes, check the brake gap is too large, the brake shoe anchor pin whether the rust die and so on.

• • Automatic brake and elimination of bad judgments
  Failure

(1) motor cars and brake, the brake acceleration of small
(2) Automotive emergency braking, the braking distance is too long, stop after the inspection, the wheel no tire drag, or delay printing printing too short

1, start the engine, so that one-speed running 4min, observe whether the barometer reading to the required value.
① If the barometer reading is low and the engine stop switch is not obvious after the pressure dropped, indicating slower air compressor pressure should be checked. Check the compressor belt is too loose or oil and slip, if the belt too loose or oil, should be adjusted or cleaned. Check whether the compressor to the gas storage bobbin Road, rupture, leakage, if leakage should be welded repair or replacement. Remove the compressor out of the trachea and the relief valve piping, hand-block compressor outlet tests, check the air pressure conditions. If the low pressure gas pressure, indicating compressor failure, there should be checks the disintegration of the intake valve is Mifengbuyan or spring break, compressor piston, piston ring and cylinder wear and tear over whether the very and so on, according to inspection, replacing the corresponding parts. If the air pressure and normal pressure, indicating pressure regulating valve to adjust improper or too soft spring should be adjusted or replaced. ② If the barometer direction normal pressure in the engine stalling after declining the engine flameout, no foot brake pedal, check whether there is leakage to listen to sound, indicating brake valve leakage, or reservoir to the brake pump piping leakage. If the brake valve leakage, indicating brake valve into the valve seat Mifengbuyan or card should be repaired or replaced; if the reservoir between the pump to the brake pipe leakage should be welding repair or replacement.
2, if the barometer indicated value to meet the requirements, will step on brake pedal pressure, after declining in the end, should check here to listen to leakage. ① If the pressure tube leak should be welding repair or replacement; ② If the brake chamber leakage, indicating brake chamber diaphragm rupture, should be replaced; ③ If the brake valve leakage, indicating brake diaphragm rupture, should be replacement.
3, if depresses the brake pedal, no sound leak. ① Check brake pedal free travel is to meet the requirements, if the free path is too large, should be adjusted; ② check the brake pressure if the maximum output to meet the requirements, if the maximum output pressure is too low, should be adjusted. ③ Check brake friction brake drum and brake shoe is the gap between films meet the requirements, if the brakes between the barrier is too large, should be adjusted.
4, branch from wheels, brake wheels were opened. ① Check brake cam shaft and the stent is Songkuang or movement blocked, if blocked Songkuang large or movement, should maintenance or lubrication. ② Check the status of brake shoe friction film, if oil should be cleaned; if they break or wear-off or rather, should be replaced. ③ check the brake shoe on the rotation in the bearing pin is flexible, if it blocked the phenomenon of movement should be lubricated. ④ Check brake drum inside a round face, if a serious groove, or roundness error is too large to be boring.

• • Automatic brake deviation of the judgments and exclusion
  Failure phenomenon:

(1) brake, the car driving to the side of the partial
(2) The brake must seize the steering wheel in order to keep the vehicle moving straight.
1, in a good road, the vehicle emergency braking tests, if the wheels are basically the same drag and India. ① Check the tire pressure around the wheel, tread and wear, if the tire pressure is inconsistent, should be required to tire inflation. If the tire tread or a side of a tire wear will not be serious, should be replaced. ② Check the status of the front suspension springs, break or stretch if not equal, should be replaced; ③ check the before and after the bridge, wheelbase, if the before and after the bridge is not parallel, indicating a broken suspension spring dislocation or fixed bolts loose, should be replaced or solid. ④ Check the frame from time to time deformation, if deformation, should be corrected.
2, if the test of tires dragging India, especially in India and inconsistent about 2 trailer. When they find a wheel brake not working, or delay printing a shorter one person can step on brake pedal movement, and the other person to inspect the wheel brake chamber and brake status. ① check whether the leak to listen to the phenomenon, if leakage, indicating brake chamber diaphragm rupture, trachea, or connector leakage, it should be replaced or repaired. ② Check brake chamber telescopic putter, and if putting bending or card should be repaired. ③ shore up the wheels, remove the brakes to view the manhole covers observation, if the brake gap is too large, should be adjusted; if the brake shoe friction film on oil should be cleaned. ④ brakes were opened. Check friction plate condition, if the friction film had very worn, hardened, or rivets are exposed and should be replaced. Check brake shoe return spring conditions, break or stretch if weakened, should be replaced. Brake drum measuring roundness and cylindrical-degree if it has been ultra-poor, should be boring. Check the brake arm and brake shoe rotation is flexible, if card phenomenon, should be lubricated.
3, if the brake in the car when suddenly the left deviation, suddenly has the right deviation. ① Check measurement of front wheel toe, if the anterior bundle of non-compliance should be adjusted. ② check turned horizontal, straight ball head pin is Songkuang, if Songkuang shows ball pin adjustment too loose or too worn or rather, should be adjusted or replaced.

• • Automatic braking lag judgments and exclusion
  Failure phenomena:

(1) Auto start difficulties, inability to drive
(2) motor cars and, after a certain mileage, brake drum heat, sliding distances have been shortened
1, first, the vehicle road test, road test, we should wish to use the brakes, while driving, after a certain mileage, parking brake drum wheel to check the temperature. ① If it is found the individual brake drum fever, stating that the wheel braking lag. ② If it is found all the brake drum heat, indicating the entire vehicle braking lag.
2, If it is found the individual brake drum fever, may be a continuous in-cab ride, the lift brake pedal, the other person at the wheel brake chamber were observed the action of putting. ① If the putter back to bit slower, indicating putter bending, card, or a broken spring brake chamber, brake oil air indoors serious and should be repaired or cleaned. If at this time putting back to normal subjects, indicating brake arm camshaft lubrication poor, should bear grease. If the putter back to normal subjects, indicating brake arm camshaft lubrication poor, should bear grease. ② If at this time putting bits back to normal, then the branch from the wheel. Check brake clearance, if the gap is too small, should be adjusted. Axial push-pull wheel test, should be feeling Songkuang shows that the wheel hub bearings Song Kuang, should adjust the bearing preload degrees. ③ check the brake shoe back to bit the situation, if the brake shoes back bit slow or not to return to places, indicating a broken brake shoe return spring, or elastic weakened, brake shoes and the bearing pin lubrication bad, should be replaced or lubrication.
3, if it found that all brake drum fever, should check the status of brake control mechanism. ① shit, lift brake pedal, brake pedal return observation of places, if the brake pedal can not be completely back to places, indicating even the rods and brake pedal shaft lubrication card or bad, should be repaired or lubrication. ② Check whether the brake riding free trip to meet the requirements, if the free path is too small, indicating brake through the small opening of the exhaust valve should be adjusted. ③ depresses the brake pedal and quickly looked up, checking to listen to the sound system, the exhaust valve. If the exhaust brake rapidly, indicating failure in the wheel brakes, should be comprehensively examined. If the exhaust brake slowly, and the delay time is too long, indicating poor exhaust valve exhaust, brake inspection should be demolished, check the exhaust exhaust valve clearance, exhaust valve return spring is broken, elastic too valve surface with small or gum, etc., according to adjusted or replaced.