Removal and installation
Disconnect lever 12 (Fig. 6-22) from rod 7, and then collar 18 from bracket 14 and the bracket for fastening the pipes going to the pressure regulator.
Fig. 6-22. Pressure regulator drive parts:
1 - pressure regulator; 2 - axis of the regulator drive lever; 3 - mudguard cap; 4 - locking plate; 5 - bolt with spring washer; 6 - rear axle beam; 7 - connecting rod of pressure regulator drive lever with rear axle bracket; 8 - bolt washer 11; 9 - plastic sleeve; 10 - spacer sleeve; 11 - traction control bolt; 12 - pressure regulator drive lever; 13 - drive lever support sleeve; 14 - support sleeve bracket; 15 - washer; 16 - spring washer; 17 - nut; 18 - support sleeve housing; 19 - bolt for fastening the clip to the bracket.
Disconnect the muffler suspension parts from the body and move the pipeline with the mufflers to the side.
After unscrewing the bolts securing the regulator to the bracket and the bracket to the body, remove the regulator bracket, and then, lowering the regulator down, disconnect the pipes from it.
Remove the regulator and disconnect the drive lever from it. Plug the inlet and outlet openings of the pressure regulator and pipelines.
Install the pressure regulator in the reverse order of removal. Before tightening the regulator mounting bolts, install the 67.7820.9519 tool (fig. 6-6). Direct the rod of the device upwards until it stops against the body. This sets the distance to (150±5) mm (see "Adjusting the position of the pressure regulator") between the end of lever 2 and the body side member.
Lift the protective cap 3 (Fig. 6-22) and, turning the regulator on the mounting bolts, ensure that the end of the lever is in light contact with the regulator piston.
Holding the regulator in this position, tighten its mounting bolts to the limit, then coat the axle 2 and the protruding part of the piston with a layer of DT-1 or Ditor grease. Install the rubber cap 3 in place, putting 5-6 g of the same grease into it.
Remove the 67.7820.9519 tool and connect the end of the lever to the rod 7, having first coated the bushings of the hinge joint of the rod with the lever with DT-1 or Ditor grease.
Attach the exhaust system pipes to the body.
Bleed the brakes to remove air from the rear brake system.
Disassembly and assembly
Using key A.56124, unscrew the plug, remove gasket 5 (Fig. 6-23), take out piston 10, spacer sleeve 2, seal 7, plate 8, spring 9 and thrust washer with sealing ring 3.
Fig. 6-23. Rear brake pressure regulator in the non-working position:
A - normal pressure cavity; B - adjustable pressure cavity; P - force transmitted by lever 4 of the regulator drive; 1 - regulator body; 2 - spacer sleeve; 3 - sealing ring; 4 - regulator drive lever; 5 - gasket; 6 - cork; 7 - seal; 8 - spring plate; 9 - piston spring; 10 - piston.
When assembling, which is carried out in the reverse order, lubricate all parts with brake fluid.
Warning: To distinguish the pressure regulator of VAZ-2121 and 21213 cars from similar-looking pressure regulators of other cars, there is a groove on the bottom of the piston.
Wash the parts with isopropyl alcohol or brake fluid and inspect. The surfaces of the parts should not have any scratches or roughness.
Check the condition and elasticity of the spring, the length of which in a free state should be 17.8 mm, and under load 76.44-64.68 N (7.8-6.6 kgf) - 9 mm.
Replace damaged parts, as well as the seal and O-ring.