To perform the operation on pumping the brake mechanisms, you will need help.
Replace when the engine is not running, first in one circuit and then in another in the following sequence:
- brake mechanism of the right back wheel.
- brake mechanism of the left front wheel.
- brake mechanism of the left back wheel.
- brake mechanism of the right front wheel.
With a spanner wrench or a “10” head, we loosen the tightening of the bleeding fitting. We put a hose on the fitting, and immerse its free end in a container partially filled with working fluid.
The assistant must vigorously depress the brake pedal 4–5 times and hold it depressed.
At the same time, fluid with air bubbles will flow out of the hose, and the brake pedal will go forward.
As soon as the fluid stops flowing out of the hose (while the pedal should reach the stop), we wrap the fitting, and only after that the assistant can release the pedal.
We repeat pumping until the liquid coming out of the hose becomes light. We remove the hose, wipe the bleeder plug dry and put on a protective cap on it.
Similarly, we pump the brake mechanisms of another circuit.
When pumping, you need to monitor the fluid level in the tank and add fluid.
We pump the hydraulic brake system until a new fluid (lighter than the old one) starts to come out of the bleeders for all the working cylinders. After pumping, bring the fluid level in the reservoir of the hydraulic brake to the norm.
There is an even simpler option for replacing brake fluid. This method does not require the presence of an assistant. With this method, a certain supply of brake fluid (at least 1 liter) is desirable.
We install the car on a viewing ditch or overpass and provide free movement between the reservoir with brake fluid in the engine compartment and the brake cylinders of all four wheels.
We pump out the brake fluid with a rubber bulb or syringe from the reservoir. Add new fluid to the top edge. To speed up the process (to release fluid from all cylinders at once), it is advisable to choose four pieces of tubes that fit tightly on the pumping fittings of all cylinders. The free ends of the tubes are lowered into transparent bottles of small capacity.
We turn off the fittings of all the brake cylinders. We make sure that the fluid flowed through all four tubes. We control the decrease in fluid from the tank located on the brake cylinder, and immediately replenish the tank. We observe an increase in the liquid level in bottles located near the wheel brake cylinders.
It is necessary to move several times from the position of observing the flow of fluid from the brake cylinder fittings to the position where it is possible to check and replenish the fluid level in the tank located on the brake cylinder to prevent the tank from being drained.
Usually, the level rises most rapidly in the bottle into which the hose coming from the brake cylinder of the front left wheel is lowered. As soon as about 200 ml of liquid is in the bottle of the front left wheel, we wrap and tighten the fitting of this cylinder. Next, we wait for the same result for the cylinder of the front right wheel and also wrap its pumping fitting. The process can be completed after 200–250 ml of liquid comes out through the fitting of each rear wheel.