Engine Oil Pressure Adjustment

TM 5-4320-234-34

Disassembly. Disassemble the oil filter as shown in figure 3-5.

WARNING

Clean all parts in a well-ventilated area.

Avoid inhalation of solvent fumes and

prolonged exposure of skin to cleaning

solvent. Wash exposed skin thoroughly.

Dry cleaning solvent (fed. Spec. P-D-680)

used to clean parts is potentially

dangerous to personnel and property. Do

not use near open flame or excessive heat.

Flash point of solvent is 100 to 138 F (38 to

59 C).

(2) Clean all remaining parts with cleaning

solvent (Fed. Spec. P-D-680). Use compressed air to

blow debris from tubes and hoses.

(3) Inspect the hose for abrasion, cracks,

deterioration, damaged threaded ends, and collapsed

walls; replace a damaged hose.

(4) Inspect the tube for dents, cracks,

damaged tube nuts, and collapsed walls; replace a

damaged tube.

(5) Inspect the filter body and cover for

cracks, distortion, dents, damaged threads, and other

damage; replace a defective body or cover.

(6) Inspect the oil pressure sender for

cracks, dents, and damaged threads. Check the sender

in series with a 12-volt battery and the oil pressure gage

mounted on the control panel. Use a low pressure,

calibrated air supply when you run the test. The sender

must provide proper resistance at various pressures to

Replace damage or inaccurate parts.

(7) Inspect all other parts for cracks,

distortion and damaged threads. Replace damaged

parts.

Reassembly and Installation. Reassembly

and installation are the reverse of removal and

disassembly. Refer to figure 3-4 and 3-5. After filling

the engine lubricating system with oil per LO 5-4320-

234-12, start the engine and check for oil leaks. Correct

any leaks.

3-15. Engine Oil Pressure Adjustment

cove screw

Decal

Screw gasket

Oil filter body

If oil pressure is consistently low, you can make

Decal

10.

Screw

the necessary pressure adjustment as follows:

Cover

11.

Lock washer

Start the engine and allow it to warm to

Cover gasket

12.

Nut

operating temperature. Check the engine oil pressure

Spring

13.

Decal

indicated on the oil pressure gage. At idle speed the

Filter element

14.

Oil filter clamp

Figure 3-5. Oil filter assembly, exploded view

pressure must exceed 7 psi; at governed speed it must

be between 20 and 30 psi.

Cleaning and Inspection.

If the engine oil pressure is not within the

(1) Discard and replace the oil filter

required range, shut off the engine and remove the plug

element and gaskets.

(1, fig. 3-6) and gasket (2) from the carburetor side of

the engine block. Remove the valve spring (3) and

pressure adjusting washer (4).

3-7