ISC, ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9 Engines – 007-014   Lubricating Oil Filter Bypass Valve

If the pressure drop across the lubricating oil filter exceeds a predetermined set point, the oil filter bypass valve opens and allows lubricating oil to bypass the lubricating oil filter.

This condition can occur during cold ambient (cold lubricating oil) engine start-ups.

The purpose of the bypass valve is to maintain lubricating oil flow to the engine and to prevent an oil filter collapse.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

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.

CAUTION  Use caution when disconnecting or removing oil filters and that oil is not spilled or drained into the bilge area. Do not drop or throw filter elements into the bilge area. The oil and oil filters must be discarded in accordance with local environmental regulations.

• Disconnect the batteries. Refer to Procedure 013-009 in Section 13.
• Remove the lubricating oil filter. Refer to Procedure 007-013 in Section 7.
• Remove the lubricating oil filter head. Refer to Procedure 007-015 in Section 7.
• Remove the 3/4-inch pipe plug from the end of the oil filter head.

Use a screwdriver to gently push down on the top of the bypass valve to remove it from the bore.

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.

WARNING  Some solvents are flammable and toxic. Read the manufacturer’s instructions before using.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Clean the bypass valve with solvent.

Dry with compressed air.

Inspect the bypass valve seat for damage. Make sure the valve fully closes.

Insert the bypass valve into the bore. The spring should be pointing upward into the bore.

Gently push the bypass valve into the bore until it seats.

Install the 3/4-inch pipe plug into the end of the oil filter head.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

• Install the lubricating oil filter head. Refer to Procedure 007-015 in Section 7.
• Install the lubricating oil filter. Refer to Procedure 007-013 in Section 7.
• Connect the batteries. Refer to Procedure 013-009 in Section 13.
• Operate the engine and check for leaks.