Car sense

Mini brake system troubleshooting

Brake system is one of the most important safety device, in the event of failure, failure to take timely measures, the consequences would be disastrous. Mini vehicle (such as Changan, songhuajiang) common failures and repair methods of the braking system is as follows:

     a  , poor braking or failure;

1, the brake pipe (joint) leak or blockage, not enough brake fluid, brake oil pressure drop and failure. Should regularly check for leaking brake line, remove, add brake fluid, clear lines.

2, slow brake pipe into the air brake. Brake pipe heating and residual pressure is too small, so that the brake fluid is gasified to make pipeline bubbles, because the gas can be compressed, thus resulting in decreased braking force when the brake. Maintenance when the brake cylinder and air exhaust and add brake fluid as required.

3, improper braking clearance. Brakes working face with wall working face of the brake drum is not braking when the gap is too large, brake, wheel cylinder piston stroke too large, slow and braking, braking force decreases. Fan fully adjust brake clearance for maintenance, that is, using a flat screwdriver to adjust the hole pull ratchet, will brake open, gap eliminated, and ratchet back 3~6 teeth, to get the required clearance.

4, bad contact with the friction of the brake drum, brake drum brake shoes deformed or roundness over 0.5mm above, leads to poor contact with the drum, brake friction declined. If this phenomenon must be boring or repairing. After the boring of the brake drum diameter not greater than 220mm, it should be replaced with new parts.

5, brake oil contamination or soaking wet friction coefficient of lift sharply and cause brake failure. Maintenance remove the friction disc cleaning with gasoline, with a blowtorch, heat baking, oil seeps in the infiltration of people; oil leakage when replacing the new piece. Flooding of the friction discs, available continuous braking to produce the heat so that the water evaporates, recovery, the coefficient of friction.

6, brake master cylinder, pump leather Cup (or other) damaged brake lines towards the necessary pressure and the oil leak, poor braking. Decomposition decomposition should be timely dismantling the brake master cylinder, pump leather Cup, replacing abrasive damage to parts.

     second, the brake side

1, consistent with the time axis left brake, mostly uneven brake clearance on either side or contact area caused by differences. This phenomenon can be provided to re-adjust gap between front and rear wheel brake, grinding friction plate when necessary, makes the front wheels ahead of the rear wheel brake.

2, with different axle brakes braking force on either side, wheel speed, straight driving distance is not equal ' so as to cause brake side. This is usually a side brake cylinder leakage, serious brake oil, friction coefficient caused around variance or unequal tire pressure. Available gasoline cleaning pads, adjust the tyre pressure, fix leaks, respectively, shall be excluded.

3, the car does not brake automatically sliding to one side. This deformation of the front suspension for one side; front suspension underbody deformation; severe decline in front suspension coil spring; and other relevant parts of the frame during braking to interfere with or to coordinate with each other. In such circumstances, identify reasons to repair.

4, auto wheel to one side when braking deviation. Working mainly on both sides of the drum brake and friction surface roughness is different, or caused one side brake line or connector plug into air. Should be checked separately containing source, to repair.

5, left and right deviation caused by uneven tire pressure. About tire inflation must be consistent, otherwise the actual turning radius wheels on both sides, driving in a straight line from sideslip occurs, to set standards for all tires.

6, in addition to the above reasons, there are about inaccurate wheel alignment and tire wear are different, poor resistance of the road on the left and right wheels will make salt deviation sideslip. In such circumstances, containing reasons respectively, in accordance with the regulations to be set or changed.

     c, brake noise

1, failure of the brake drum circle, its roundness than 0.5mm. Brake drums deformation (Oval), brake and drum fitting moment occur collisions, and produce a sharp impact sound. Maintenance remove brake drum boring according to standards, and the need to balance performance check, unbalanced control within the

2, brake lining surface is too smooth braking pressure, friction coefficient, large, smooth surface sliding friction noise generated when grinding, or foreign bodies were stuffed into extrusion friction between the friction surfaces, friction noise can also occur. Remove brake drum for maintenance, removal of foreign bodies, coarse sandpaper and linings, and with the Deputy contact area is more than 70%.

3, severe wear of brake friction plate, surface grooves and irregular shapes, to fitting and brake drum brake is not available, or the brake support plate deformation and damage the drum and concentricity, local friction, impact and noise. Repair, replace the friction plates, brake support plate correction.

4, front wheel bearing, roller and ball bearing surface pits, grooves, even fragmentation, brake noise will occur. Replace front wheel bearing, you can eliminate this noise.

     four the brake drum, brake dragging causing fever

1, brake clearance is too small, the pedal free travel is small, when relaxing brake pedal, the brake is not fully lifted, prolonged friction make friction pairs; starting difficulties, weakness, hand touching the drum surface is hot. In this case the brake clearance should be adjusted according to the specifications again.

2, the brake handle is not fully open, because improper adjustment or operational negligence, leading to prolonged friction heat of friction pairs and, if necessary, adjusted according to the specifications.

3, the heat from the brake return spring thermal deformation, elastic drop or disappear, not guarantee brake assembly back in a timely manner, will not be able to completely remove brake drum fever in a timely manner. Should repair or replace return spring can eliminate the fault.

     v, parking brake

common cables or coat rust, traction spring break, fall off or loss of elasticity, causing parking brake control cable or brake cable pull is not flexible in their coat, hand brake loose and work failures. Brake control cable and brake system components should be checked for lesions on the surface, stick control movement is flexible, no sticking phenomenon; loose cable connector and the fixed part is damaged, repair or replacement, if necessary.

repair cable filling grease lubrication or replacement of damaged, repair specification brake handle to turn again. 196N force is applied to the parking brake handle, pulling up the handle plate moving 5~7 a tooth to fully brake parking for normal stroke of the handle if tooth plate moves over more than 7, then brake clearance is too large or cable extension should now be adjusted.  

Good Luck To Guilin Automobile Service Co.

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