Chevrolet Repair: Cooling engine test, cooling system, thermostat

Question
Hi Randy,
When I run a cooling engine pressure test do I have to disconnect the thermostat?
Everybody is saying just atach the pump to the radiator and pump to the prescribed pressure, but nobody is saying about the thermostat.
Do you have any suggestions?
Thanks,
Petric

Answer
Petric,

No need to do anything with the thermostat; pressure will go through the entire system just fine. Attach your tester and pressurize to the proper level, then inspect for leaks.
You may need to have your cooling system completely full to find your leak.