Cummins/Onan — Coolant Heat Exchanger Pressure Test
Testing & diagnosis
From a Cummins/Onan owner's manual covering: 6CTA8.3, CFP83-F10, CFP83-F20, CFP83-F30, CFP83-F40. Check it applies to your exact model before use.
Applies to: Cummins/Onan 6CTA8.3, Cummins/Onan CFP83-F10, Cummins/Onan CFP83-F20, Cummins/Onan CFP83-F30, Cummins/Onan CFP83-F40, Cummins/Onan 6CTA8.3G2 engine, Cummins/Onan 6CTAA8.3G3 engine
Before you start
- If leakage is detected, the heat exchanger must be replaced.
Procedure
- Install a 1-1/4" NPT pipe plug at the raw water outlet of the heat exchanger.
- Install a pressure test setup with a 700 kPa [100 psi] pressure gauge at the 1" NPT raw water inlet.
- Apply air pressure at 621 kPa [90 psig].
- Isolate the pressure source and monitor the pressure gauge for 5 minutes.
- Release the pressure, then remove the pipe plug and the test setup.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Apply air pressure at 621 kPa [90 psig]
- Heat exchanger rated at 414 kPa [60 psig]
- No detectable decrease in the pressure reading for the duration of the test
Full service-parts list: Cummins/Onan CFP83-F10 →, Cummins/Onan CFP83-F20 →, Cummins/Onan CFP83-F30 →, Cummins/Onan CFP83-F40 →
Source: Cummins/Onan owner'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.