The pressure regulator is mounted on the compressor cylinder block. To increase the reliability of the pressure regulator, it is equipped with two filters:

One filter 8 is installed at the air inlet from the pneumatic system, the other filter 7 is installed at the air inlet to the regulator from the compressor unloader.

ZIL-131 pressure regulator

The pressure regulator automatically maintains the required compressed air pressure in the system by letting air into or out of the compressor unloader.

When the pressure in the pneumatic system reaches 7.0-7.4 kg/cm², the regulator turns off the air supply to the compressor, and when the pressure drops to 5.6-6.0 kg/cm², it turns on the compressor again.

If the pressure in the pneumatic system is not maintained within the specified limits, then it is necessary to determine the cause of the malfunction and eliminate it.

The reason for violation of the pressure limits in the pneumatic system may be a malfunction of the pressure regulator or wear of the O-rings of the unloader plunger, so you must first check the tightness of the unloader plungers.

If even after eliminating the leakage of the plungers, the pressure limits do not correspond to the norm, then the regulator should be disassembled, the parts washed in gasoline or kerosene and dried.

Only qualified personnel are allowed to open and adjust the pressure regulator. It is recommended to check the pressure regulator on a special stand.

Damage to the surface of the balls and their seats is unacceptable.

The regulator is adjusted in the following sequence.

1. By rotating the cap 4, they ensure that the compressor starts up at a pressure of 5.6-6.0 kg / cm².

When screwing on the cap, the pressure increases, when unscrewing, it decreases.

The cap is fixed with locknut 16.

2. By changing the number of gaskets 15, a pressure of 7.0-7.4 kg / cm² is obtained, at which the compressor is turned off.

With an increase in the number of gaskets, the pressure decreases, with a decrease, it increases.


During operation, it may be necessary to adjust the full opening of the carburetor throttle valve and the position of the pedal

- Cause of malfunction Elimination method The clutch does not disengage completely (the clutch “drives”):