The safety valve is designed to protect the pneumatic system from excessive pressure increase in case of damage to the automatic pressure regulator

The valve is installed on the front right cylinder.

The safety valve is adjusted so that it opens when the air pressure in the pneumatic system reaches 9-9.5 kg/cm².

The valve is adjusted to a given pressure with a screw 6, which is locked with a lock nut 5.

ZIL-131 brake relief valve

It is necessary to periodically check the tightness of the valve using a soapy emulsion; to eliminate increased air leakage, the valve should be disassembled, washed in gasoline or kerosene and dried.

The seat band and ball must not have scratches or other surface damage.

During maintenance, it is necessary to check the correct operation of the safety valve of the pneumatic brake drive system.

To do this, pull the valve stem - the valve must release air.

Then you need to release the rod; if in this case the release of air stops, the valve is working normally.