HOUSING 2P0190 - Caterpillar

Unloader Mechanism (Fig. 24)
Figure 24
Unloader MechanismThe unloader pistons and their bores must be lubricated with special lubricant piece number 239379 (dimethyl polysiloxane) prior to installation. If new unloader kits are being installed, the pistons in the kit are already lubricated.Install the unloader pistons in their bores with caution against cutting the grommets or distorting the back-up rings. Position unloader plungers in their guides and slip them in and over the tops of the pistons.Install the unloader spring seat in the cylinder block; a small hole is drilled in the block for this purpose. Position the saddle between unloader piston guides so its forks are centered on the guides. Install the unloader spring, making sure it seats over the spring seats both in the block and on the saddle.Install inlet valve seats if they have been previously removed. Position and install inlet valve guides, then drop inlet valves in their guides. There should be a loose sliding fit between guides and valves.Cylinder Head Assembly
If previously removed, the discharge valve seats should be installed. Drop discharge valves into their seats. Install discharge valve springs and cap nuts.Place the inlet valve springs in the cylinder head. Use a small quantity of grease to hold them in place, just enough grease to keep the springs from falling out. Place cylinder head gasket on cylinder block. Carefully align cylinder head assembly on block and install cap screws with lock washers. Tighten securely and evenly cap screws that hold cylinder head to block.Base Plate
Self-Lubricated Type Compressors
Install oil pump piston and rod on crankshaft.Oil rod bearing fit must be the same as specified for connecting rod bearings. Install oil rod cap nuts and cotter pins to lock oil rod nuts.Install oil pump relief valve in base plate. The relief valve can be tested at this stage by applying air pressure to the relief valve. The valve should open when the pressure is between 14 psi minimum and 24 psi maximum. When the relief valve is properly installed in the base plate, install set screw that locks it in place.Place oil pump screen in base and install retaining ring, making sure it snaps in place and secures the screw.Install oil filter fitting on base plate in its proper place. Install blanking cover on opposite oil filter fitting hole in plate.Install a new oil seal gasket around oil pump--check valve and position a new base plate gasket on the crankcase. Position base plate assembly on crankcase, making sure oil pump piston engages the oil pump bushing in the base plate. Install and tighten base plate screws.
Figure 25
Air Strainer - Exploded ViewAir Strainer
If the compressor is type with air strainer, assemble strainer (Fig. 25). Using a new strainer gasket, install strainer on cylinder block.Governor
If compressor is type with pad mounted governor, install a new or factory rebuilt governor using a new governor gasket.Inspection Of Rebuilt Unit
Check to be sure that covers, plugs or masking tape are used to protect all ports if compressor is not to be installed