In the process of using the car, surely many friends have encountered the failure of the brake system, especially the brake soft and hard brakes are the most common phenomena, so what is the cause of it, and how to solve it? Let's take a look!
Brake soft causes and solutions
First, the brake fluid is not enough caused, in the solution can first open the cover to check whether the brake oil is enough, if not enough, you can make up to solve the fault. There are two scale marks on the oil pot, below the lower scale represents the lack of, generally make up the upper tick line, do not need to fill.
Second, the brake oil is dirty or the water content is high, if the brake oil is not changed for a long time, it will cause the brake to be soft, and the oil pot can be opened to measure the moisture content of the brake oil during treatment, or observe whether the oil is dirty through the naked eye, if there is a problem, replace the new brake oil to solve.
Third, the leakage of brake oil or the appearance of air in the brake oil circuit will also lead to the problem of brake softness, in the processing can first check whether there is a leak, if there is, repair can be; if not, you need to empty the brake oil circuit, after the air discharge can solve the fault of the brake soft.
Fourth, the brake total pump or sub-pump appears internal pressure relief, because the inside of the main pump is a piston to push the work, if the sealing ring is broken and damaged, it will cause insufficient oil pressure in the brake system, so that the brake soft situation, generally replace the brake pump can solve the problem.
Fifth, the brake pads of the vehicle are worn to the limit, because the brake pads are thinner, the stroke of the brake pedal will become larger, and more brakes need to be stepped on to play a role in braking, so as to feel the brake soft, the solution is to replace the brake pads.
Brake hard causes and solutions
First, the damage to the brake total pump and the sub-pump, if the piston, push rod and sealing ring inside the brake total pump are rusted, it will increase the resistance pushed by the total brake pump stroke, resulting in the failure of the brake hard, and the general replacement of the brake pump can be solved.
Second, the brake vacuum system leaks, because the brake boost is to take the engine vacuum boost, so the vacuum system problem will lead to the problem of heavy brakes, in the processing can first check whether there is a leak from the vacuum drum to the engine between the pipeline, the check valve has a stuck blockage, if there is a need to repair can be solved, the detection of pipeline leakage can use the smoke leak detector to check.
The third is the damage to the vacuum pump on the engine side, the vacuum pump is the power source for the brake vacuum boost, if his internal vacuum chamber seal is not tightly damaged or does not work, it means that the brake system at this time has no help, the brake will naturally become hard, and the solution is to replace the new vacuum booster pump.
The fourth is the line problem of the vacuum pump, because the vacuum pump of some models is not a pure mechanical drive, but an auxiliary electronic drive can, so it is necessary to focus on checking the fuse and relay, if the insurance or relay ablation, you only need to replace the fuse to solve.
Fifth, the brake sub-pump of the wheel on the guide pin rust caused, after rust, the brake sub-pump work time is extended, the rear wheel brake will also be slowed down, the solution is to remove the guide pin for descaling and apply grease.
The above is the common reason for the soft and hard brakes, I hope to help you and reduce the trouble of car maintenance and use.