Cummins 4BT 3.9 and 6BT 5.9 Thermostats

Maintain the cooling system in Cummins B-Series engines with thermostats from Diesel Parts Direct. Correct regulation of temperature is vital to the operation of 4BT and 6BT engines, so when it’s time to replace the thermostat, check out our online catalog. We have 5.9 and 3.9 Cummins thermostats in-stock and ready to ship.

Malfunctioning thermostats can lead to irreversible damage in the cylinder head. Avoid a complete rebuild by replacing the thermostat in your Cummins 3.9 and 5.9L engines during routine maintenance. Our in-stock guarantee ensures minimal downtime, as many popular parts are ready to ship the same day of purchase.

Depend on Diesel Parts Direct to deliver the parts your B-Series engines need.