Page 1162 - Foton Workshop Manual - Auman EST-M

BR-30 Brake system – service brake (air pressure)

Four circuit protective valve

Change

1. Release the pressure of braking
system 2. Remove the four-circuit protection valve.
a. Remove the air pipe connector nut connecting the
four-circuit protection valve to the air cylinder and
disconnect the air pipe connecting the four-circuit
protection valve.
Caution

When dismounting, mark or number on the air pipes
for easy installation.

b. Remove the fixing nut connecting the four-circuit
protection valve and dryer.

c. Remove the four-circuit protection valve.

3. Remove the four-circuit protection valve.

a. Place the four-circuit protection valve on the test
bench, connect the air inlet pipe, turn on the air source
switch, and check the four-circuit protection valve's
opening pressure.
b. There is air bleeding from the air outlets only when the
air inlet pressure is up to the valve opening pressure of
600kPa. If advance air bleeding or air leakage occurs at
some outlets, the valve is not in good sealing condition.
In this case, change the four-circuit protection valve.

c. Subject the four air outlets of the four-circuit
protection valve to sealing treatment. Connect the air
inlet pipe, turn on the air source switch, fill the protection
valve to the pressure of 700kPa, and check the overall air
tightness of the four-circuit protection valve.
d. Check whether the four-circuit protection valve leaks
by smearing soap water on it or putting it into water.

BR-030