MAINTENANCE OF LUBRICATION SYSTEM
SECTION I. FILTER AND OIL BY-PASS ASSEMBLY
8-1. GENERAL Oil enters the filter and oil by-pass assembly under pressure. A pressure regulator valve dumps excess
oil back into the oil pan. Oil enters the filter head from the oil cooler, then passes through the filter elements. A by-pass
valve is provided in the filter head oil inlet cavity to ensure against interruption of oil flow if filter elements become
dogged. Oil leaving the filter elements flows to the main oil passage in the block
8-2. REGULATOR VALVE DISASSEMBLY . See Figure 8-1.
Remove oil temperature sender MT2, oil pressure alarm and shutdown switch OP1/OP2, and air control box
disconnect switch OP3 from the lube oil filter head (24) in accordance with the Operator and Organizational
Remove capscrews (1 and 2) and lockwashers (3) to remove valve housing cover (4) and cover gasket (5).
Discard the gasket
Remove the regulator valve (items 7 through 10) as an assembly.
Spring load will be released when roll pins are removed. Guard against loss of parts.
Hold the valve plunger guide (7) and regulator valve plunger (9) against the spring force, and remove roll pins
Remove valve plunger guide (7), regulator valve spring (8), and regulator valve plunger (9) from regulator valve
housing (10 ).
Observe caution when removing by-pass valve cover (13). By-pass valve spring (15) may
cause personal injury if spring tension is released suddenly.
Remove capscrews (11) and lockwashers (12) to remove by-pass valve cover (13) and valve cover gasket (14).
Discard the gasket.
Remove relief plunger (16), by-pass valve spring (15), and valve housing (17).
To aid in extracting piston cooling valve assembly (18), thread a 1/4 inch, 20 thread bolt,
approximately 1 1/2 inch long, into the threaded recess in the pressure regulator stop (20).
The pressure regulating valve assembly (18) may then be pulled from the lube oil filter head
Remove internal retaining ring (19), pressure regulator stop (20), piston cooling spring (21), and piston cooling
plunger (22). Remove and discard preformed packing (23).
Dry cleaning solvent, PD0680, Type Ill, or equivalent, is flammable and moderately toxic to the
skin, eyes, and respiratory tract. Assure adequate ventilation. Skin, eye, and respiratory
protection is required to avoid injury to personnel.
Compressed air used for cleaning or drying can create airborne particles that may enter the
eyes. Pressure shall not exceed 30 psi (207 kPa). Wearing of goggles is required to avoid
injury to personnel.