104
shifted in the direction of rotation and via the adjusting device presses r.h. shoe 2 to
the supporting pin and drum.
As the linings are being worn, travel of lever 1 (Fig. 84) increases and the
brake efficiency can decrease. If lever 4 is mounted on the 12 th tooth of the seg-
ment, it is required to adjust clearances between the linings and drum with the help
of eccentric and sprocket. Adjust the brake as follows:
1. Lower down the control lever 1 in the cab as far as it will go.
2. Disconnect the tie rod 4 from lever 8 on the transfer box.
Do not adjust the clearances between the linings and drum by changing tie
rod 4 length, because it results in the parking brake failure
.
3. Adjust the clearance between the r.h. shoe and drum. For this purpose slack
off lock nut 8 (see Fig. 83) on eccentric pin 9 on the side of shield by half a turn,
and turning the pin by a wrench clockwise, set a clearance of 0.3-0.5 mm. Check
the clearance with the help of checking probe through the slit in the brake baffle.
Tighten the lock nut, preventing the pin turning.
4. Adjust the clearances between the l.h. shoe and drum. For this purpose re-
move stopper 4. Set a clearance of 0.3-0.5 mm through the hole in the brake
shield, turning sprocket 5 by a screwdriver from the top down. Install the stopper.
5. Select free travel of lever 8 (see Fig. 84) on the transfer box, turning it
counter-clockwise until the effort to be applied increases appreciably, and check if
the hole in tie rod 4 fork coincides with the hole in lever 8. If required, match the
holes by rotating the fork of tie rod 4. Install the pin and cotter it.
If the effort applied on the lever in the cab is 350 – 400 N (35 – 40 kgf), the
pawl of lever 1 should be mounted on the 4 th
-
8 th tooth of segment 3. When the
pawl has passed the 2 nd
-
4 th tooth of the segment, the pilot lamp of the parking
Fig. 84. Parking Brake Control:
1 - parking brake control; 2 –
pawl; 3 – segment; 4, 9 – control
tie rods; 5 – tie rod to trailer brake
control valve; 6 – parking brake
alarm switch; 7 – shims; 8 – lever;
10 – adjusting lever
