Disassembly; Cleaning; Reassembly - Mercury MerCruiser MCM 454 Mag MPI Service Manual

454 CID (7.4L) / 502 CID (8.2L)

Disassembly

NOTE: Refer to exploded view shown previously.
1. Remove pump cover.
IMPORTANT: Mark gear teeth for reassembly with same teeth indexing.
2. Remove idler gear and drive gear from pump body.
3. Remove retaining pin, spring, and pressure regulator valve from pump cover.

Cleaning

1. Wash all parts in cleaning solvent and dry with compressed air.
2. Inspect pump body and cover for cracks or excessive wear.
3. Inspect pump gears for damage and excessive wear.
4. Check for loose drive gear shaft in pump body.
5. Inspect inside of pump cover for wear that would permit oil to leak past ends of gears.
6. Inspect pickup screen and pipe assembly for damage to screen and pipe.
7. Check pressure regulator valve for fit.
IMPORTANT: Oil pump is not serviceable. If any parts are worn or damaged, replace-
ment of entire pump assembly and pickup tube is necessary.

Reassembly

NOTE: Refer to exploded view shown previously.
IMPORTANT: Oil internal parts liberally before installation.
1. Install pressure regulator valve and related parts.
2. Install drive gear in pump body.
3. Install idler gear in pump body with smooth side of gear toward pump cover opening.
Align marks made in disassembly.
4. Fill gear cavity with engine oil.
5. Install pump cover and torque attaching screws to 106 lb-in. (12 Nm).
6. Turn extension shaft by hand to check for smooth operation.
Index
Page 3A-52
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SERVICE MANUAL NUMBER 23
90-861326--1 MARCH 1999