It is recommended to change the brake fluid with an assistant, having previously installed the car on a viewing ditch or overpass
It is advisable to change the brake fluid once a year.
Use brake fluids of at least DOT-4 grade.
The sequence of replacing fluid in the brakes:
- - right back;
- - left front;
- - Left back;
- - right front.
The hydraulic drive of the brakes is pumped to remove air that got there when filling with liquid after its replacement or after repair of the hydraulic drive units associated with its depressurization.
Signs of air in the hydraulic drive:
- — Increasing the pedal travel, its “softness when the pedal is pressed once;
- - a gradual decrease in the pedal travel with a simultaneous increase in its “rigidity” with repeated pressing on the pedal.
Before bleeding the hydraulic drive, it is necessary to find and eliminate the cause of the depressurization.
The actions when bleeding the hydraulic drive are the same as when changing the brake fluid, described below.
The only difference is that it is not required to first pump out the old brake fluid from the reservoir, and the criterion for completing the pumping of the working cylinder is the cessation of the release of air bubbles from the hose, and not the appearance of fresh brake fluid.
We unscrew the cap of the reservoir of the master brake cylinder
We pump out the old fluid from the tank and fill the tank with new brake fluid up to the lower edge of the filler neck
If the rear wheels are suspended, unlock the brake pressure regulator by inserting a screwdriver between the plate and the piston
We clean the air release valves from dirt and remove the caps from the front brake valves
Removing the caps from the rear brakes
We put a plastic or rubber hose on the air release valve of the right rear wheel
We lower the end of the hose into a clean transparent bottle.
The assistant presses the brake pedal four to five times and then keeps the pedal depressed.
Unscrew the air release valve by ½ - ¾ turn.
Old brake fluid will start to flow from the hose.
At this time, the brake pedal should smoothly come to the stop. As soon as the liquid stops flowing out, we wrap the air release valve.
Constantly monitor the liquid level in the reservoir, not allowing it to drop to the MIN mark on the side of the reservoir.
Add new brake fluid as necessary to keep air out of the hydraulic system.
Thus, a gradual displacement of the old fluid by the new one is ensured without draining the hydraulic system.
In the same way, we replace the brake fluid in the brake mechanism of the left front wheel.
Next, we replace the brake fluid in the brake mechanism of the left rear wheel, then the right front wheel.
We repeat operations 5-9 until the fluid in the drive is completely replaced (a clean fluid without bubbles should flow out of the hose).
We take out the screwdriver (if inserted) between the plate and the piston of the brake regulator.
Checking the brakes. We press the brake several times - the pedal travel and the effort on it should be the same with each press.
Add the brake fluid to the level between the MAX and MIN marks on the tank wall and tighten the plug.
We put on protective caps on the brake cylinder release valve.