Pressure Testing a C-1 Cooling System

[Richard T.]

When pressure testing a C-1 (62) cooling system for leaks with a hand held pump tester is it better to test with the engine cold and the thermostat closed or warmed up so it's open? Rich

[Terry D.]

Re: Pressure Testing a C-1 Cooling System

Back in the day we always let them warm up first
Terry

[Richard T.]

Re: Pressure Testing a C-1 Cooling System

Thanks Terry, I was thinking that was the correct way but wqasn't sure. Rich

[Larry M.]

Re: Pressure Testing a C-1 Cooling System

When pressure testing a C-1 (62) cooling system for leaks with a hand held pump tester is it better to test with the engine cold and the thermostat closed or warmed up so it's open? Rich

It probably doesn't matter. Having the thermostat open/closed won't affect the test. The pressure will equalize on both side of the thermostat. Plus thermostats are generally not "bubble tight" when they are closed, and likely exhibit some leakage in this position.

Depending on the problem, a leak may show up more pronounced one way (cold versus warm) than the other. Do them both.

If you test warm, be certain that it is really warm and not hot. You don't want to get yourself burned by hot (140 F and above) coolant.

Larry