ISC, ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9 Engines – 008-016   Coolant Thermostat Seal

WARNING  Coolant is toxic. Keep away from children and pets. If not reused, dispose of in accordance with local environmental regulations.

WARNING  Do not remove the pressure cap from a hot engine. Wait until the coolant temperature is below 50°C [120°F] before removing the pressure cap. Heated coolant spray or steam can cause personal injury.

CAUTION  Use caution when draining coolant that coolant is not spilled or drained into the bilge area. Do not pump the coolant overboard. If the coolant is not reused, it must be discarded in accordance with local environmental regulations.

NOTE: This procedure applies only to QSL9 engines with keel cooling.

• Drain the engine coolant. Refer to Procedure 008-018.
• Remove the coolant thermostat housing. Refer to Procedure 008-014.
• Remove the coolant thermostat. Refer to Procedure 008-013.

CAUTION  Use care when removing the thermostat seal, the thermostat housing can be damaged.

Use a punch and hammer to remove the seal from the housing.

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

Use solvent to clean the thermostat housing.

Dry with compressed air.

Inspect the thermostat housing for cracks, pits, or other damage.

When installing a new seal, the part number side of the seal must be facing the mandrel.

Use thermostat seal mandrel, Part Number 3375411, and a hammer to install the seal.

Install the thermostat in the housing.

Install a new o-ring in the groove on the thermostat housing mounting surface.

Install the thermostat housing cap over the end of the housing using three capscrews. Tighten the capscrews.

• Install the thermostat housing. Refer to Procedure 008-014.
• Fill the engine with coolant. Refer to Procedure 008-018.

Operate the engine and check for leaks.