Oil Pump: Service and Repair

OIL PUMP

REMOVAL
1. Disconnect negative cable from battery.
2. Remove front timing belt cover.
3. Remove timing belt.
4. Remove timing belt tensioner assembly.
5. Remove the camshaft sprocket and the rear timing belt cover.
6. Remove the oil pan.





7. Remove crankshaft sprocket using Special Tool 6793 and insert C-4685-C2 (Fig. 115).
8. Remove the oil pick-up tube.





9. Remove fasteners securing oil pump to engine block. Remove oil pump (Fig. 116) and front crankshaft seal.

DISASSEMBLY
1. To remove the relief valve, proceed as follows:





2. Remove the threaded plug and gasket from the oil pump (Fig. 117).

CAUTION: Oil pump pressure relief valve must be installed as shown in (Fig. 117) or serious damage may occur.

3. Remove spring and relief valve (Fig. 117).
4. Remove oil pump cover screws, and lift off cover.
5. Remove pump rotors.





6. Wash all parts in a suitable solvent and inspect carefully for damage or wear (Fig. 118).

INSPECTION
1. Clean all parts thoroughly. Mating surface of the oil pump should be smooth. Replace pump cover if scratched or grooved.





2. Lay a straightedge across the pump cover surface (Fig. 119). If a 0.076 mm (0.003 inch) feeler gauge can be inserted between cover and straight edge, cover should be replaced.





3. Measure thickness and diameter of outer rotor. If outer rotor thickness measures 7.64 mm (0.301 inch) or less (Fig. 120), or if the diameter is 79.95 mm (3.148 inch) or less, replace outer rotor.





4. If inner rotor measures 7.64 mm (0.301 inch) or less replace inner rotor (Fig. 121).





5. Slide outer rotor into pump housing, press to one side with fingers and measure clearance between rotor and housing (Fig. 122). If measurement is 0.39 mm (0.015 inch) or more, replace housing only if outer rotor is in specification.





6. Install inner rotor into pump housing. If clearance between inner and outer rotors (Fig. 123) is 0.203 mm (0.008 inch) or more, replace both rotors.





7. Place a straightedge across the face of the pump housing, between bolt holes. If a feeler gauge of 0.102 mm (0.004 inch) or more can be inserted between rotors and the straightedge, replace pump assembly (Fig. 124). ONLY if rotors are in specs.
8. Inspect oil pressure relief valve plunger for scoring and free operation in its bore. Small marks may be removed with 400-grit wet or dry sandpaper.
9. The relief valve spring has a free length of approximately 60.7 mm (2.39 inch) it should test between 18 and 19 pounds when compressed to 40.5 mm (1.60 inch). Replace spring that fails to meet specifications.
10. If oil pressure is low and pump is within specifications, inspect for worn engine bearings, damaged or missing oil pick-up tube O-ring, clogged oil pick-up tube screen, clogged oil filter and stuck open pressure relief valve or other reasons for oil pressure loss.

ASSEMBLY
1. Install oil pump rotors (Fig. 118).
2. Install oil pump cover and screws (Fig. 118). Tighten screws to 12 Nm (105 inch lbs.).

CAUTION: Oil pump pressure relief valve must be installed as shown in (Fig. 117) or serious damage may occur.

3. Install spring and relief valve (Fig. 117).
4. Install threaded plug and gasket to the oil pump (Fig. 117). Tighten plug to 41 Nm (30 ft. lbs.).

INSTALLATION
1. Make sure all surfaces are clean and free of oil and dirt.





2. Apply Mopar Gasket Maker to oil pump as shown in (Fig. 125). Install o-ring into oil pump body discharge passage.
3. Prime oil pump before installation.
4. Align oil pump rotor flats with flats on crankshaft as you install the oil pump to the block.

NOTE: Front crankshaft seal MUST be out of pump to align, or damage may result.

5. Torque all oil pump attaching bolts to 28 Nm (250 inch lbs.).





6. Install new front crankshaft seal using Special Tool 6780 (Fig. 126).

NOTE: Make sure the word "front" on the crankshaft sprocket is facing outward.

CAUTION: Use of Special Tool 6792 is required to install the crankshaft sprocket to the proper depth. Failure to use this tool will cause improper timing belt tracking.





7. Install crankshaft sprocket, using Special Tool 6792 (Fig. 127).
8. Install oil pick-up tube and oil pan.
9. Install timing belt rear cover and camshaft sprocket.
10. Install timing belt tensioner assembly.
11. Install timing belt.
12. Install front timing belt cover.
13. Fill engine crankcase with proper oil to correct level.
14. Connect negative cable to battery.