Checking the performance of the pressure regulator (VAZ-21213)

Place the car on a lift or inspection pit, clean the pressure regulator and protective cover from dirt.

Carefully remove the protective cover from the pressure regulator, remove any remaining grease and clean the torsion-piston connection.

Ask an assistant to press the brake pedal with a force of 686-784 N (70-80 kgf) and simultaneously observe the protruding part of the pressure regulator piston. If the piston moves relative to the regulator body by 0.5-0.9 mm, while twisting the torsion lever, then the pressure regulator is operational. Repeat pressing the pedal 2-3 times to fully verify the functionality of the pressure regulator.

If the piston remains stationary when you press the pedal, which indicates that the piston is frozen to the housing, replace the pressure regulator.

After making sure that the pressure regulator is working properly and that there is no leakage of brake fluid between the piston and the pressure regulator housing, coat the axle and the protruding part of the piston with a thin layer of DT-1 grease, place 5-6 g of this grease in the rubber boot and install the boot in place.

(The original is posted on Internet resource VAZbook)