Inspection

Figure 114-Checking Oil Pump Cover Flatness:

INSPECTION AND REPAIR
1. Clean all parts thoroughly. Mating surface of the oil pump housing should be smooth. Replace pump cover if scratched or grooved.
2. Lay a straightedge across the pump cover surface. If a 0.076 mm (0.003 inch) feeler gauge can be inserted between cover and straight edge, cover should be replaced.

Figure 115-Measuring Outer Rotor Thickness:

3. Measure thickness and diameter of outer rotor. If outer rotor thickness measures 14.299 mm (0.563 inch) or less, or if the diameter is 79.78 mm (3.141 inches.) or less, replace outer rotor.

Figure 116-Measuring Inner Rotor Thickness:

4. If inner rotor measures 14.299 mm (0.563 inch) or less replace inner rotor.

Figure 117 Measuring Outer Rotor Clearance In Housing:

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

Figure 118 Measuring Clearance Between Rotors:

6. Install inner rotor into body. If clearance between inner and outer rotors is 0.20 mm (0.008 inch) or more, replace both rotors.
7. Place a straightedge across the face of the body, 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 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 49.5 mm (1.95 inches) it should test between 23 - 25 pounds when compressed to 34 mm (1 - 11/32 inches). Replace spring that fails to meet specifications.

OIL PUMP ASSEMBLY
1. Assemble pump, using new parts as required.
2. Tighten cover screws to 12 Nm (105 inch lbs.).
3. Prime oil pump before installation by filling rotor cavity with engine oil.
4. If oil pressure is low and pump is within specifications, inspect for worn engine bearings or other reasons for oil pressure loss.