102
accessories, with the check pressure gauge to coupling head 18, «A» type. Fill in the
brake system with the compressed air until the pressure, when the compressor dis-
engages, is reached. The air pressure on the check pressure gauge should be
500-520 kPa (5.0-5.2 kgf/cm
2
). Then press the brake pedal and engage the park-
ing brake. In so doing the check pressure gauge should read zero.
Check the pressure value on control coupling head 16 and feed coupling head
17 of the double
-
line drive. The air pressure in the feed coupling head should be
equal to the pressure in the system, and the pressure in the control coupling head
should be equal to zero. When pressing the brake pedal and engaging the parking
brake, the air pressure in the control head should be equal to the pressure in the
system.
To ensure the proper operation of the pneumatic drive, drain the condensate
from the air bottles. Follow this procedure, if the air is available in the pneumatic
system. During a cold period drain the condensate when the truck leaves a warm
garage. After draining the condensate from the bottles fill in the system with the
compressed air until the rated pressure is reached.
If the ambient temperature is below 0 °C, and if the trucks are stored out of
doors, a special care should be taken to drain the condensate from the air bottles. If
the condensate has been frozen, it is required to warm up the frozen areas with hot
water or steam.
Do not heat the units by exposing them to the open flame (torch, a solder-
ing lamp, etc.).
Fill in the hydraulic drive system with fluid and pump through the brakes
when the air pressure is available in the truck pneumatic system. Prior to filling in
the system remove mud from the brake master cylinders and tanks. Then having
removed the sealing pipe and screwed off the filler plug, fill in the tanks with
braking fluid and remove the air from the hydraulic system.
The order of pumping through the brake master cylinders and wheel cylinders
of the service brakes should be as follows:
- remove the rubber cap from the bypass valve of the master cylinder; put the
valve on the pipe available in the set of tools; immerse the open end of the pipe
into the braking fluid poured in a glass vessel, having a capacity, minimum 0.2 l. Fill
in the vessel with the braking fluid up to half its height;
- screw out the bypass valve through 1/2-3/4 of a turn and then press the
brake pedal several times (press quickly, release slowly). Press the pedal repeatedly
until no air bubbles come out of the pipe immersed in the vessel with the braking
fluid. When pumping through the cylinders, add fluid into the tanks to prevent the
air penetration in the system;
- hold the pedal pressed, screw in the cylinder bypass valve tight, remove and
put on the cap;
- pump through the wheel brake cylinders, keeping the following order: the
intermediate l.h., rear l.h., rear r.h., intermediate r.h., front r.h., front l.h. cylinders;
- upon pumping through all the cylinders add the fluid into the tanks up to
the level of 15-20 mm lower the filler upper edge and screw on the filler plug.
When changing the braking fluid, disassemble the wheel and master cylinders,
flush the working surfaces of the parts. When assembling the wheel cylinders, apply
the braking fluid onto the piston and cylinder inner surface. To enhance the corro-
sion resistance of the wheel cylinders apply 4-5 g of
ДТ
-1 grease onto the cylin-
der face under each wheel cap.
