This procedure covers the replacement of the Single Cylinder Air
Compressor Cylinder Head Assembly Kit, Cummins kit part number
4089208. The repair kit includes a complete head assembly (manifold,
valves, cover, etc.) new head bolts, coolant seals, and gaskets.
Gasket and Seal Kit, Cummins kit part number 4089240 can be used if
necessary to replace leaking cylinder head gaskets and coolant seals
(assuming the cylinder head is serviceable). The repair kit includes a
head gasket, two cover gaskets, intake valve, head bolts, cover assembly
bolts, sump plug, and rear flange adapter with O-ring seal.
Note the locations of all air and coolant fittings. Then remove and retain all air and
coolant fittings installed in the air compressor head (1, Figure I-1).
Remove and discard four head bolts (2) "A, B, C, & D", Figure I-2. Bolts "A", "C", and
"D" are 3-1/8 in. (80 mm) long and bolt "B" is 4-1/8 in. (105 mm) long.
Note the orientation of the head assembly (1, Figure I-1) with respect to the air
Remove and discard the head assembly (1) and head gasket (3).
Rotate air compressor crankshaft until the piston is at the top of the cylinder bore.
Many cleaning solvents are toxic, flammable, and/or may cause skin and
eye irritation. Strictly follow the manufacturer's instructions and use eye
protection, gloves, and protective clothing. Use in well-ventilated areas
away from heat and open flames. Use good personal hygiene prior to
eating, drinking, or smoking.
Do not use abrasive products that will leave grit after cleaning. Do not
allow debris and cleaning solvent to enter the area between the piston
and cylinder bore.
Remove any carbon and varnish build-up by carefully scraping. If necessary, use a light
application of cleaning solvent.
Ensure all surfaces are clean, dry, and free of debris.