UAZ HUNTER 315148, Operating Manual, Page: 101 / 136

101
When pressing the brake pedal, the proportioning valve piston
should move out from the housing by 1.7-2.3 mm. If the piston
has no stroke, as well as a poor or excessive stroke, the valve or
its drive have malfunctions.
When inspecting the hydraulic drive, pay attention to the
position of gauge plug 15 and to the absence of brake fluid leaking
from it. The plug should normally be sunk into the housing
orifice of the valve, up to the stop. If the plug comes out or the
brake fluid leaks, the valve must be repaired or replaced.
During the operation and replacement of back leaf-springs,
adjust the force of flexible arm 5 (Fig. 9.37) to the valve piston.
For adjustment do the following:
1. Place the vehicle with its curb weight on an even level ground.
2. Loosen the lock-nut of adjusting bolt 4 and unscrew the
bolt for 2-3 turns.
3. Tighten bolt 4 (see Fig. 9.37) until it touches the regulator
piston end 17 (see Fig. 9.36) by screwing the adjusting bolt for
1...11/3 turn (6-8 flats of the bolt head).
4. Check the stroke of the valve piston (see above).
5. Check adjustment correctness during motion of the vehicle.
While going on a straight level road with a dry surface, brake
the vehicle until the wheels lock. If the valve is in order and
drive adjustment was done correctly, the front wheels should
be blocked slightly earlier than the rear ones. If the rear wheels
are blocked earlier, unscrew bolt 4 (see Fig. 9.37) by 1-2 flats
of the bolt head and check the brakes in motion again.
Fig. 9.37. Proportioning valve drive:
1 — Proportioning valve; 2 — bracket (base); 3 — drive lever; 4 — adjusting
bolt; 5 — flexible lever; 6 — lever pillar