Cummins ISX11.9 CM2250 – Service Manual 007-021   Lubricating Oil High Pressure Relief Valve

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.

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

• Remove the lubricating oil pump. Refer to Procedure 007-031 in Section 7.

Remove the high-pressure relief valve and spring by removing the threaded retaining plug from the lubricating oil pump cover.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

Clean the high-pressure relief valve and spring with solvent and a bristle brush.

Inspect the spring for broken coils or rust.

A damaged or rusty spring must be replaced.

Inspect the high-pressure relief valve. A slight ring around the top of the valve from contact with the pump body is acceptable.

If any cracks, scuffing, or deep ring grooves are found on the valve, it must be replaced.

Use a spring compression tester, Part Number 3375182, to measure the relief valve spring tension.

Compress the spring to 55.67 mm [2.19 in] height. The force required to compress the spring must meet these specifications.

Force Required to Compress Spring to 55.67 mm [2.19 in]

WARNING  The high-pressure relief valve spring is under compression. Slowly remove the threaded retaining plug to reduce the possibility of personal injury.

Install the high-pressure relief valve and spring into its bore in the lube pump housing.

CAUTION  Engine oil pressure must be indicated on the gauge within 15 seconds after starting. If oil pressure is not registered within 15 seconds, shut off the engine immediately to avoid engine damage. Confirm the correct oil level in the oil pan.

• Install the lubricating oil pump. Refer to Procedure 007-031 in Section 7.
• Operate the engine at idle speed for 3 minutes to inspect for leaks.