Pumping the brakes with ABS is not more difficult than pumping a conventional car brake system. But in order to remove the air from the brake system with ABS system properly, it is recommended to understand the principle and pattern of its operation at your car. Because the pumping pattern may vary slightly depending on the model. For example, when the hydrovalve unit and hydraulic accumulator with the pump are in the same block, both the replacement of the fluid and the pumping of the brake system with ABS are performed in a similar way as the pumping of the brakes without ABS.
Types of ABS systems
- ABS includes: hydrovalve unit, hydraulic accumulator, pump (pumped in a garage);
- Pump, hydraulic accumulator and hydrovalve unit are placed in different blocks. In addition to the ABS module, this brake system includes additional ESP, SBC modules (pumped in a service station). You should have a diagnostic scanner to monitor the modulator valves.
Based on the features, we can conclude that before you pump the brakes with ABS, determine the type of your system, since this instruction will be relevant only for a standard anti-lock system.
The process of pumping the brakes with ABS
In order to perform the task properly, it is desirable to pump the system with an assistant, starting to pump the brake system from the front wheels, then the rear wheels (right and left).
Pressure relief is performed by the pressure accumulator discharging. To do this, turn off the ignition and press the brake pedal about 20 times. Then disconnect the connectors on the master cylinder reservoir to move to the next stage of the brake pumping.
General principle of pumping the brakes with ABS
- Find and remove the fuse in the unit responsible for the operation of ABS.
- Unscrew the wheel and find the wheel brake cylinder connection for pumping the brake.
- Start pumping the brakes with ABS when the pedal is depressed.
- Turn on the hydraulic pump (when you start up the ignition, the ABS lamp on the dashboard will light up) and wait until all the air is removed.
- Tighten the connection and release the brake pedal, if the ABS lamp does not lights up any longer, everything is done correctly and the air is completely removed.
The sequence of the air removal from a vehicle
Pump the front right brake first, and then the left. The procedure is performed with the ignition off (position «0») and the terminal removed on the master cylinder reservoir.
- Put on a hose with a small bottle on the connection and open it (with a spanner wrench). It is necessary to put on a transparent hose so that air bubbles can be seen, and the other end of the hose should be completely in a liquid.
- Depress the pedal fully and hold it, until all the air is removed.
- Tighten the connection and release the pedal, when the liquid is without air.
Rear wheels are pumped with the ignition on at the key position «2».
- Put on the hose on the connection for pumping on the caliper, as in case of pumping the front wheels.
- Depress the pedal fully, turn the ignition key (to start the hydraulic pump). Monitor the air removal and control the brake fluid level in the tank (fill it from time to time).To prevent the pump from fault, it is necessary to monitor the brake fluid level constantly (in order to prevent dry running). And avoid continuous operation for more than 2 minutes.
- Shut off the connection when the air bubbles have been completely removed, turn off the pump and depress the brake pedal.
To pump the brakes with ABS on the rear left wheel properly, it is necessary to change the sequence of actions slightly.
- As in previous cases, put the hose on the connection and untighten it not completely, but only by 1 turn, and do not depress the pedal.
- Turn the ignition key to start the hydraulic pump.
- As soon as the air is removed, depress the brake pedal to half and tighten the pumping connection.
- Then release the brake pedal and wait for the pump to stop.
- Cut off the ignition and connect the removed connector to the tank.
If you need to pump the brakes together with the ABS modulator, information on such a procedure can be found here.
It is obligatory to check the tightness of the system and the absence of leaks after pumping the brakes. Check the level of brake fluid.