105
brake engagement on the dashboard should turn on. To adjust the moment of its
turning on, change the number of shims 7 under alarm switch 6.
Auxuliary brake system
The compression
-
type auxiliary brake is intended to reduce the truck travel-
ling speed, when moving downhill for a long time. Braking is performed by estab-
lishing counter
-
pressure in the exhaust gas lines when cutting them off by flaps.
The brake consists of body 3 (Fig. 85) and a flap. The flaps are driven by air cylin-
ders 1 fixed with the help of a bracket on the auxiliary brake body.
If it is required to brake the truck, press the button of the auxiliary brake
control air valve located on the cab floor. The compressed air is supplied to the air
cylinders, the pistons move, closing the flaps. Simultaneously, the signal to the
trailer brake drive is transmitted and its light braking occurs.
When the valve button is released, the air goes out of the cylinders to the at-
mosphere; the rods under the action of the return spring turn the levers and flaps to
their initial position.
The locked drive, synchronous with engaging the auxiliary brake, cuts off the
fuel feed. The design of the air cylinder, cutting off the fuel feed, is similar to that
of the auxiliary brake air cylinder.
When travelling with the auxiliary brake engaged:
- the engine speed should not exceed 2100 min
-1
;
- do not shift the gears in the gearbox from the high to low one at the engine
speed close to 2100 min
-1
.
If required, reduce the engine speed with the help of the service brake and
engage the low gear.
If flap 4 of the auxiliary brake turns with difficulty, remove the brake body with
the flap, rinse in kerosene, blow through with the compressed air. If the air cylinder
rods or air valve seize, disassemble the assembly units, rinse in kerosene, replace the
faulty parts, apply lubricant onto the friction surfaces and put them into place.
To adjust the position of the flaps, change the length (L) of screwing off the air
cylinder rod with fork.
If the flap is installed properly, the key is located alongside the intake pipe
axis, with the air cylinder piston in its extreme r.h. position.
Fig. 85. Auxiliary Brake:
1 - air cylinder; 2 - drive tie rod fork; 3 - body;
4 - flap; 5 -flap shaft lever; 6 - key; 7 - pin; 8 -
cotter pin
