Cummins ISX11.9 CM2250 – Service Manual 012-024   Air Pressure Relief Valve

Verify the unit is equipped with an air pressure relief valve.

Remove the air governor or air governor line from the air compressor. Remove the air intake line from the air compressor cylinder head.

CAUTION  Do not hold hand too close to the intake port of the air compressor. Personal injury can result.

Operate the engine to activate the air compressor.

Hold your hand 5 cm [2 in] from the air compressor intake port. If air is coming out of the intake port, the pressure relief valve is malfunctioning and the air compressor cylinder head must be replaced. Refer to Procedure 012-007 in Section 12.

If no air is felt from the intake port, check downstream air system components for damage or restrictions.

Install the air intake line to the cylinder head. Install the air governor or air governor line to the air compressor.