ISM, ISMe, and QSM11 – 007-029   Lubricating Oil Pressure Regulator (Main Rifle)

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.

• Drain the lubricating oil. Refer to Procedure 007-037 in Section 7.
• Remove the oil pan. Refer to Procedure 007-025 in Section 7.

WARNING  Carefully remove the retainer plug. The pressure regulator spring is under compression. Personal injury can result. Wear face and eye protection.

Remove the retainer plug (1), regulator spring (2), and regulator plunger (3).

Remove the orifice from the plunger.

Inspect the regulator plunger for scratches or scoring. If scratches are deep enough to be felt with a fingernail, the plunger must be replaced.

Check the orifice in the plunger to make sure it is not plugged. If the orifice is plugged, clean it before replacing.

The orifice is threaded into the plunger.

Measure the free length of the regulator spring.

Regulator 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.

Main Oil Pressure Regulator Spring Load at 48.3 mm [1.90 in]

Measure the retainer plug to determine if it is defective. If it does not meet the specification, replace it with a new one.

Main Oil Pressure Regulator Retainer Plug

WARNING  The regulator spring must be compressed to install the retainer plug. Personal injury can result. Wear face and eye protection.

NOTE: A counterbore plunger and orifice is unique to engines with a viscosity sensor. Low oil pressure will result if a solid plunger is used with a viscosity sensor.

Install the regulator plunger (3) and regulator spring (2).

Install and tighten the retainer plug (1).

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 oil pan. Refer to Procedure 007-025 in Section 7.
• Fill the engine with clean 15W-40 engine oil. Refer to Procedure 007-037 in Section 7.
• Operate the engine at idle for 3 minutes and check for leaks.