Cummins/Onan — Filling heat exchanger
Maintenance · Heat exchanger cooling system
From a Cummins/Onan operator's manual covering: 12.5RDJC-518R, 12.5RDJC-53CR, 12.5RDJC-57R, 15.0RDJC-18R, 15.0RDJC-3CR, 15.0RDJC-4R, 15.0RDJC-4XR, 15.0RDJC-5DR, 15.0RDJC-9XR. Check it applies to your exact model before use.
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Before you start
- After running unit 10 minutes the closed cooling system is pressurized and hot. Open the 14 pound pressure cap slowly to vent pressure.
Procedure
- Remove fill cap.
- Open fill vent valve (turn counterclockwise).
- Remove vent plug.
- Fill with coolant until vents begin to overflow.
- Close fill vent valve (turn clockwise).
- Replace vent plug and fill cap.
- Operate unit 10 minutes at full load and watch for leaks.
- Shut down unit; slowly open pressure cap, check level, fill system to top with coolant.
Specs & values
- 14 pound pressure cap
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.