3500 4x2 Pickup V8-360 5.9L Magnum (1994)
Oil Pump: Service and Repair
Oil Pump Service
Service of oil pump requires pump to be removed.
See: Oil Pump Replacement
Fig. 32 Oil Pump
With pump removed, disassemble pressure relief valve by pulling out cotter pins and drilling a 1/8 in. hole into center of relief valve retainer cap. Insert a
self-threading sheet metal screw into cap and secure head in vise. While supporting pump body, remove cap by tapping body with soft hammer. Discard
retainer cap and remove spring and relief valve. Relief valve spring has a free length of 1.95 in. and should test between 19.5 and 20.5 lbs. when
compressed to 1.34 in. Any spring that fails to meet specifications must be replaced. Unbolt oil pump cover and discard oil seal ring. Inner rotor and
shaft can now be removed as well as outer rotor. Clean all parts thoroughly and inspect for damage or wear. If mating surface of oil pump cover is
scratched or grooved, replace pump assembly.
Fig. 33 Oil Pump Cover Flatness Inspection
Lay a straightedge across pump cover surface. If a 0.0015 in. feeler gauge can be inserted between cover and straightedge, replace pump assembly.
