Centinel System – Repair Manual – 007-021   Lubricating Oil High Pressure Relief Valve

The high-pressure relief valve (1) is held in the closed position by spring force (2). The valve remains in the closed position until the oil pressure exceeds 1034 kPa [150 psi] in the lubricating oil pump.

When the oil pressure exceeds 1034 kPa [150 psi] in the lubricating oil pump, for instance, during cold start-up, the oil pressure in the pump overcomes the relief valve spring force.

This allows the excess oil to return to the oil pan, preventing possible damage to the lubricating system components.

WARNING  To reduce the possibility of personal injury, avoid direct contact of hot oil with your skin.

WARNING  Some state and federal agencies have determined that used engine oil can be carcinogenic and cause reproductive toxicity. Avoid inhalation of vapors, ingestion, and prolonged contact with used engine oil. If not reused, dispose of in accordance with local environmental regulations.

Remove and disassemble the lubricating oil pump. Refer to Procedure 007-031.

Inspect the ball. A slight ring around the ball from contact with the pump body and spring is acceptable.

Measure the spring free length.

Use a spring compression tester to determine if the spring is defective.

Replace the spring with a new spring if it is defective.

Assemble and install the lubricating oil pump. Refer to Procedure 007-031.

Operate the engine to normal operating temperature and check for leaks.