Cummins ISX11.9 CM2250 – Service Manual Air Compressor Will Not Pump Air

Air intake system restriction to air compressor is excessive

Replace the air compressor air cleaner (if installed). Check the air intake piping. Check the engine air intake restriction if the air compressor inlet is plumbed to the vehicle or equipment intake system. Refer to Procedure 010-031 in Section 10
.

Unloader system is malfunctioning

Check the unloader system and head assembly system. Replace the head assembly if required. Refer to
Procedure 012-003 in Section 12
.

Air compressor cylinder head is cracked or porous, or has a leaking gasket

Inspect the air compressor cylinder head and gasket. Refer to
Procedure 012-003 in Section 12
.

Air compressor is excessively worn or internally damaged

Replace the air compressor. Replace the desiccant element on the air dryer, if equipped. Refer to Procedure 012-014 in Section 12 and the OEM service manual.