Cummins/Onan A052J727 — Replacing the Thermostat
Repair & overhaul · Cooling system
For the Cummins/Onan A052J727, from the Cummins/Onan operator's manual.
Applies to: Cummins/Onan MDKD
Before you start
- Hot coolant is under pressure and can spray, causing severe burns.
Procedure
- Disconnect the negative battery cable and let the engine cool.
- Remove the pressure cap.
- Drain the cooling system.
- Remove two thermostat housing bolts; pull off housing, thermostat, and gasket.
- Clean the gasket area; install the new thermostat and gasket.
- Apply Three Bond 1215 liquid sealant or equivalent to gasket top side.
- Replenish lost coolant and secure the pressure cap.
Tools required
- Insulated wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Three Bond 1215 liquid sealant or equivalent
Full service-parts list: Cummins/Onan MDKD →
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.