6.2.1. Check and adjustment of elements of brake system
Brakes check on the dry and equal road, on various speeds of the car with easy and strong pressing a brake pedal, avoiding blocking of brakes and sliding of tires.
Process of braking is influenced by three main factors:
– on different wheels there will be unequal conditions of coupling of tires from darling that causes unequal brake forces. Pressure of air and protectors of tires should be identical;
– brake forces on lobbies and back axes should be proportional to vertical loadings operating on them;
– violation of corners of installation of wheels can become the reason of that the car when braking will pull aside.
For check of leakage of brake liquid press a brake pedal at operation of the engine on frequency of rotation of idling and installation of the lever of switching of a transmission in neutral situation. If the pedal gradually fails at constant pressure, means there is a leak in system. Visually check existence of leak and level of brake liquid in a tank of the main brake cylinder. Insignificant falling of level of brake liquid occurs because of normal wear of blocks. Abnormally low level speaks about leak in system. In hydraulic system it is possible both internal, and external leak. If level of brake liquid in norm, check length of a rod of the vacuum amplifier of brakes. If the inadequate length of a rod is found, adjust length or replace a rod.
Check the main brake cylinder in the following order:
- on absence of damages and leakage of brake liquid round the main brake cylinder. Fall of level of brake liquid can speak only about leak existence. An abnormal condition is also moistening of a surface of the main brake cylinder;
- connection of draft of a pedal and length of a rod. If they in norm, disassemble the main brake cylinder and check on stretching or swelling of epiploons of the cylinder, then – on lack of wear of rubber details. If epiploons inflated, the non-standard or polluted brake liquid is probably used. If the polluted brake liquid is found, all metal components should be disassembled and cleared, and all rubber – to replace. All pipelines should be washed out also.
Improper brake liquid, mineral oil or availability of water in liquid can cause boiling of brake liquid or damage of rubber components. If the main epiploons of the piston in the main cylinder bulked up, means rubber components are spoiled. If wear of rubber is found, disassemble all details of hydraulic system and wash out them alcohol. Before assembly dry details a stream of the compressed air. Replace all rubber details in system, including hoses. At operation of the brake mechanism check lack of liquid in laying. If liquid is found, replace laying. If a condition of epiploons of the piston of the main brake cylinder normal, check existence of leak or an excessive overheat. If these conditions are not found, merge brake liquid, fill the main brake cylinder and repeatedly merge liquid from system.
Table 6.5 Possible malfunctions of brake system, their reason and ways of elimination