We check the pressure regulator with an assistant on the inspection ditch.
We clean the regulator and the protective cover from dirt. We remove the protective cover from the regulator and remove the remaining grease from the place where the piston touches the end of the lever.
The assistant presses the brake pedal with a force of 70–80 kgf. At the same time, we observe the movement of the protruding part of the regulator piston.
In a serviceable regulator, the piston movement should be 0.5–0.9 mm. If the piston remains motionless when you press the pedal, replace the regulator.