Before starting work: Remove the pressure regulator from the vehicle and drain the brake fluid from it.
If fluid leaks from under the plug, a partial repair of the pressure regulator can be carried out. If other defects are found that require special equipment to eliminate, replace the regulator assembly or contact a specialist workshop.
1. Clamp the pressure regulator body in a vise and unscrew the regulator plug.
2. Remove the sealing ring. Replace damaged ring.
3. Remove the push rod spring...
4....spring seat and...
5.... pusher assembly with o-rings and bushing. If it is difficult to remove the pusher...
6.... supply compressed air to the hole in the regulator housing for the brake pipe (shown by arrow).
7. Remove the first o-ring from the pusher...
8....sleeve...
9....a second O-ring and...
10....thrust washer.
11. Flush all parts with brake fluid.
12. Replace both O-rings regardless of their condition.
13. Replace a broken or loose pushrod spring. Its length under load (14±1,5) H or (1,4±0,15) kgf should be 7.5 mm.
14. Checking the tightness of the pressure regulator valve, rolled in the plug, is possible only in a specialized workshop. Replace the defective valve complete with plug.
15. Assemble the regulator in the reverse order of removal, lubricating all parts with brake fluid. At the same time, pay attention to the installation of sealing rings: with their conical part, they should be directed towards the sleeve.