Impreza Sedan AWD F4-1820cc 1.8L SOHC (1993)
Measure the tip clearance of rotors. If the clearance exceeds the limit, replace rotors as a matched set.
Tip clearance:
Standard 0.04 - 0.14 mm (0.0016 - 0.0055 in).
Limit 0.18 mm (0.0071 in).
CASE CLEARANCE
Measure the clearance between the outer rotor and the cylinder block rotor housing. If the clearance exceeds the limit, replace the rotor.
Case clearance:
Standard 0.10-0.175 mm (0.0039 - 0.0069 in).
Limit 0.20 mm (0.0079 in).
SIDE CLEARANCE
Measure clearance between oil pump inner rotor and pump cover. If the clearance exceeds the limit, replace rotor or pump body.
Side clearance:
Standard 0.02- 0.07 mm (0.0008 - 0.0028 in).
Limit 0.12 mm (0.0047 in).
OIL RELIEF VALVE
Check the valve for fitting condition and damage, and the relief valve spring for damage and deterioration. Replace the parts if defective.
Relief valve spring:
Free length; 71.8 mm (2.827 in).
Installed length; 54.7 mm (2.154 in).
Load when installed; 77.08 N (7.86 kg, 17.33 lb).
OIL PUMP CASE
Check the oil pump case for worn shaft hole, clogged oil passage, worn rotor chamber, cracks, and other faults.
OIL SEAL
Check the oil seal lips for deformation, hardening, wear, etc. and replace if defective.
ASSEMBLY