Cummins/Onan — Removing/Installing the Heat Exchanger
Repair & overhaul
From a Cummins/Onan operator's manual — check it applies to your exact model before use.
Applies to: Cummins/Onan MDKB, Cummins/Onan MDKBH
Before you start
- Take special care not to scratch the face on the aluminum manifold.
Procedure
- Disconnect the two leads at the flow sensor, remove the sensor and disconnect the three hoses.
- Loosen the hose clamps on both ends to work the coolant hose elbow off the fitting.
- Remove the four mounting bolts and withdraw the heat exchanger.
- To install, clean the mating gasket faces (do not scratch the aluminum manifold face) and use a new gasket.
- Torque the mounting bolts to 19 lb-ft (26 N-m).
- Install the flow sensor using pipe thread sealant and reconnect the two leads in the harness, then reconnect the hoses and reassemble.
Specs & values
- Torque heat exchanger mounting bolts to 19 lb-ft (26 N-m)
Full service-parts list: Cummins/Onan MDKB →, Cummins/Onan MDKBH →
Source: Cummins/Onan operator's 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.