Oil Pump: Service and Repair

OIL PUMP/PRESSURE REGULATOR VALVE






IMPORTANT
^ It is not necessary to remove the balancer assembly to service the oil pump or pressure regulator valve. Refer to Balance Shaft. Service and Repair

REMOVE OR DISCONNECT
1. Oil pan, refer to "Oil Pan".

DISASSEMBLE
1. Restrictor.
2. Filter.
3. Oil pump cover assembly.
4. Oil pump gears.

CAUTION: The pressure regulator valve spring is under pressure. Exercise caution when removing the pin, as bodily injury may result.

5. Pressure regulator valve.
^ Plug or pin
^ Spring
^ Valve. If the valve is stuck, clean the valve and pump housing with carburetor cleaning solvent.

CAUTION: Avoid breathing of fumes, or exposure of the skin to the cleaning solvent, as bodily injury may result. When working overhead, wear eye protection.

CLEAN
^ All parts of sludge, oil and varnish.
^ Varnish on parts may be removed by soaking in carburetor or cleaning solvent.

INSPECT
^ For foreign material and determine source.
A. Pump housing and oil pump cover assembly for:
^ Cracks
^ Scoring
^ Casting imperfections

B. Pressure regulator valve for:
^ Scoring
^ Sticking. Burrs may be removed with a fine oil stone.

C. Pressure regulator valve spring for:
^ Loss of tension
^ Bending
^ If in doubt, replace the spring.

D. Screen assembly for:
^ Looseness
^ Broken wire mesh or screen
^ Oil pump gears for:
^ Chipping
^ Galling
^ Wear

MEASURE
^ Gear housing pocket depth.
^ Gear thickness.

IMPORTANT
^ When deciding pump serviceability based on pocket depth, consider depth of wear pattern in gear pocket and face of oil pump cover assembly.

ASSEMBLE
1. Lubricate all internal parts with engine oil.

NOTICE: To avoid engine damage, all pump cavities must be packed with petroleum jelly before installing the gears to assure priming.

2. Pump gears.
3. Oil pump cover assembly.
4. Pressure regulator valve and spring.
5. Plug or pin.

IMPORTANT
^ Make sure the pin is properly secured.

6. Oil pump cover assembly.

TIGHTEN
^ Bolts to 10 Nm (90 lb. in.).

CLEAN
^ Oil pump intake screen
^ Oil pan

7. Filter.
8. Restrictor.

INSTALL OR CONNECT
1. Oil pan, refer to "Oil Pan".
2. Fill crankcase with clean engine oil.

INSPECT
^ Remove the oil pressure sending unit and install an oil pressure gage.
^ Start engine and observe oil pressure.

NOTICE: If the oil pressure does not build up almost immediately, remove the oil pan and examine pump. If necessary, disassemble the oil pump and repack all cavities with petroleum jelly. Running the engine without measurable oil pressure will cause extensive damage.

^ Check for bearing knock. If necessary, disassemble and check for adequate oil supply and proper clearances.