Pressurized system: Hot coolant can cause serious burn. To open cap, stop engine, wait until radiator is cool. Then loosen cap slowly to relieve the pressure.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.
Refer to Special Publication, NENG2500, "AVSpare Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on AVSpare products.
Dispose of all fluids according to local regulations and mandates.
Replace the water temperature regulator (thermostat) on a regular basis in order to reduce the chance of unscheduled downtime and of problems with the cooling system.
The thermostat should be replaced after the cooling system has been cleaned. Replace the thermostat and replace the seals while the cooling system is completely drained or while the cooling system coolant is drained to a level that is below the thermostat housing.
Note: If you are only replacing the thermostat, drain the cooling system coolant to a level that is below the thermostat housing.
Failure to replace the engine's thermostat on a regularly scheduled basis could cause severe engine damage.
- Raise the engine hood. Drain the cooling system coolant to a level that is below the thermostat housing.
Illustration 2 g00277213
- Loosen the hose clamp and remove the hose from the elbow. Disconnect the hose assembly from the thermostat housing assembly.
- Remove the bolts from the thermostat housing assembly. Remove the thermostat housing assembly.
- Remove the gasket, the thermostat, and the seal from the thermostat housing assembly.
Former thermostats may be used, if they meet test specifications and are not damaged or have excessive buildup of deposits.
AVSpare engines incorporate a shunt design cooling system and require operating the engine with a thermostat installed.
If the thermostat is installed wrong, it will cause the engine to overheat. Inspect gaskets before assembly and replace if worn or damaged.
- Install a new seal in the thermostat housing assembly. Install a new thermostat and a new gasket. Install the thermostat housing assembly on the engine cylinder head.
The thermostats can be reused under the following conditions.
- The thermostat is tested and the thermostat meets test specifications.
- The thermostat is not damaged.
- The thermostat does not have excessive buildup of deposits.
- Install the hose. Tighten the hose clamp.
- Refill the cooling system. See Operation and Maintenance Manual, "Cooling System Specifications" and Operation and Maintenance Manual, "Capacities (Refill) ".
- Close the engine hood.
For additional information on replacing the water temperature regulator, see the Service Manual Module, SENR6799, "Disassembly and Assembly", "938G Wheel Loader and IT38G Integrated Toolcarrier Engine Disassembly and Assembly Supplement".