Detroit Diesel — Install Thermostats
Maintenance
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- Attempting to reuse defective thermostats and/or seals can result in inefficient engine operation and/or damage.
Procedure
- Always install a new seal when replacing a thermostat. Install new seals in the thermostat housing covers with installer J 8550 and driver handle J 7079-2, lips facing up away from the thermostats.
- Install the thermostats in the thermostat housing covers.
- Place new gaskets on the thermostat housings. Attach the covers to the housings and tighten the bolts to 30-35 lb-ft (41-47 N*m).
- Slide the radiator or heat exchanger-to-thermostat housing hoses over the covers and secure with hose clamps.
- Close the thermostat housing drain cocks and fill the cooling system to the proper level. Start the engine and check for leaks.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Thermostat housing cover bolts 30-35 FridayParts $14.81 KuduParts $233.00 lb-ft (41-47 N*m)
Source: Detroit Diesel service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.