Oil Pump Service

DISASSEMBLE & INSPECTION

1. Remove pump cover to body retaining screws, then the pump cover.

Fig.22 Oil Pump Gear End Clearance Inspection:

2. Measure gear end clearance by positioning Plastigage across the full width of each gear as shown. Reinstall pump cover and tighten to specifications. Remove cover and determine clearance by comparing compressed Plastigage with scale on Plastigage envelope. Clearance should be 0.002-0.006 inch. If clearance is excessive, replace oil pump.

Fig.23 Oil Pump Gear To Body Clearance Inspection:

3. Measure gear to pump body clearance by inserting a feeler gauge between each gear tooth and the pump body inner wall as shown. Clearance should be 0.002-0.004 inch. If clearance is excessive, replace idler gear, shaft and drive gear assembly.
4. If checking pressure relief valve, remove pickup tube and screen assembly and position aside. Remove cotter pin, then slide spring retainer, spring and pressure relief valve plunger out of pump body. If plunger binds during removal, clean or replace plunger as necessary. Relief valve plungers are available in standard or 0.010 inch oversizes. When replacing plunger, ensure correct size is installed.

ASSEMBLE

1. Install relief valve plunger, spring, retainer and cotter pin.
2. If pickup tube and screen assembly was removed, install replacement assembly as follows:
a. Apply a light coat of Permatex No.2 sealant, or equivalent, to end of pickup tube.

Fig .24 Oil Pump Pickup Tube & Screen Assembly Installation:

b. Using tool No. J-21882, or equivalent, drive tube into pump body as shown. Ensure support bracket is aligned properly.

3. Before installing pump cover, fill pump with petroleum jelly.
4. Install pump cover and tighten retaining screws to specifications.