Sequence of work
1. Check up all places of connections and connections of brake system, supports and the main cylinder.
Pic. 8.7. Checking brake hose wear (arrow)
2. Inspect and feel the brake hoses for damage. They must remain elastic, must not be wet, frayed or cracked. Otherwise, have them replaced by a workshop. Hoses must not be kinked or overstretched (pic. 8.7).
3. Pipelines of the brake system are protected from corrosion by a plastic braid. If it is damaged, corrosion may occur. Therefore, do not clean the pipelines of dirt with a screwdriver, wire brush or corrosive liquids.
4. Clean the pipes with a cloth and cold cleaner.
5. If the protective braid is damaged, apply a primer to the exposed areas to protect against corrosion.
6. If the pipelines are pinched or have traces of corrosion, replace them.
7. Check for protective caps on all bleeders. They are located at the top of the brake calipers.
8. Check the pressure in the brake system as follows: depress the brake pedal as far as it will go.
9. Even after several minutes of full load, the pedal should not «fall through» further, otherwise the gasket in the master cylinder has failed.
10. A leaky gasket does not cause the brake fluid level in the reservoir to drop. But the liquid, when pressurized, passes by the master cylinder piston without pressure.
11. Leaks in piston gaskets are determined only by precise inspection at the workshop.
Brake fluid level
1. If the pads of the disc brake pads are already slightly worn, the brake fluid level begins to approach the mark «MIN»; if the pads are new, the level rises again. This is natural, because with worn linings, the brake pistons go further out and leave more space in the caliper cylinders, which is filled with brake fluid. Experienced mechanics use this circumstance to determine the state of wear of the linings by the level of the brake fluid. Of course, this is only possible if no liquid has been added between check cycles.
2. Critical is the level of brake fluid in the reservoir below the mark «MIN». Since the liquid does not evaporate and is not consumed, a leak occurs. It should be discovered as soon as possible. Adding fluid will not fix the problem.
3. If there is a malfunction in the hydraulic clutch system on vehicles with a manual transmission, the brake fluid level may drop significantly. Cause: The hydraulic fluid is replenished by the brake fluid reservoir. The outlet from the reservoir to the clutch hydraulic actuator is located high enough so that a hydraulic leakage in the hydraulic actuator cannot affect the operation of the brake system.