Engine Coolant Thermostat Replacement Caterpillar
Refer to the Caterpillar® Service Manual.
Engine Coolant Thermostat Replacement 8.1L Engine
Removal Procedure
- Drain the cooling system. Refer to
Cooling System Draining and Filling
.
- Reposition the inlet hose clamp at the water outlet.
- Remove the inlet hose from the water outlet.
- Remove the water outlet bolts (2).
- Remove the water outlet (1).
- Remove the thermostat (3).
Installation Procedure
- Install the thermostat (3).
- Install the water outlet (1).
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Install the water outlet bolts (2).
Tighten
Tighten the bolts to 30 N·m (22 lb ft).
- Install the inlet hose to the water outlet.
- Position the inlet hose clamp at the water outlet.
- Fill the cooling system. Refer to
Cooling System Draining and Filling
.
Engine Coolant Thermostat Replacement LG4
Removal Procedure
- Drain the coolant. Refer to
Cooling System Draining and Filling
.
- Remove the upper radiator hose from the coolant outlet.
- Remove the coolant outlet bolts.
- Remove the coolant outlet (1).
- Remove the thermostats (2).
- Clean the following surfaces:
- Inspect the coolant outlet for the following conditions:
Installation Procedure
Important: Place the thermostat with the jiggle valves on the left side.
- Install the thermostats.
- Install the coolant outlet (1).
Notice: Refer to Fastener Notice in the Preface section.
- Install the coolant outlet bolts.
Tighten
Tighten the coolant outlet bolts to 19 N·m (14 lb ft).
- Install the upper radiator hose to the coolant outlet.
Tighten
Tighten the clamp to 5 N·m (44 lb in).
- Fill the cooling system. Refer to
Cooling System Draining and Filling
.
- Inspect the system for leaks.
Engine Coolant Thermostat Replacement 6.6L LLY
Removal Procedure
- Remove the air cleaner . Refer to
Air Cleaner Replacement
for the 6.6L (LLY) engine.
- Remove the charged air cooler pipes. Refer to
Charged Air Cooler Hoses/Pipes Replacement
.
- Remove the water outlet. Refer to
Water Outlet Tube Replacement
.
- Remove the bolt for the fuel line bracket.
- Remove the thermostat housing cover bolts.
- Remove the thermostats and seals.
Inspection Procedure
- Inspect the thermostats for sticking, cracks, and/or leakage of wax. Refer to
Thermostat Diagnosis
.
- Replace the thermostats if damage is found.
- Clean the thermostat housing and thermostat housing cover sealing surfaces.
Installation Procedure
- Install the thermostats and seals to the thermostat housing.
The rear thermostat (4) has 2 vent valves. Install with the vent valves
towards the rear of engine.
Notice: Refer to Fastener Notice in the Preface section.
- Install the thermostat housing cover.
- Install the thermostat housing cover bolts.
Tighten
Tighten the bolts to 21 N·m (15 lb ft).
- Install the fuel line bracket bolt.
Tighten
Tighten the bolt to 21 N·m (15 lb ft).
- Install the water outlet. Refer to
Water Outlet Tube Replacement
.
- Install the charged air cooler pipes. Refer to
Charged Air Cooler Hoses/Pipes Replacement
.
- Install the air cleaner . Refer to
Air Cleaner Replacement
for the 6.6L (LLY) engine.