Cooling system doesn't hold pressure (1 Viewer)

[Stecz]

How much pressure should I expect the cooling system to hold? I borrowed a cooling system pressure tester and pumped the system up to about 15 psi and can't find any external leaks, but the pressure in the tester leaked down fairly quickly (maybe 1 psi/minute)?

The only things I can think of are:
1) cooling system pressure tester was leaking pressure (could be, but the adapter seems to fit on the radiator well)
2) head gasket, although I don't have obvious water in the oil or oil in the radiator.

other thoughts?

I don't seem to be loosing coolant at an excessive rate, although it's hard to say since I just replaced the radiator and heater valve.

I do have a head gasket tester that connects to the radiator cap, so I'm going to give that a try.

 

[scottryana]

Could be an external HG leak. Some people have them at the back of the block. Also how are your heater lines?

 

[flintknapper]

Spray bottle with soapy water will tell you what you need to know.

Find your leak(s): Tester itself, adapter, hoses, O-rings, etc......be thorough. Check all the easy things first (all visible hose connections, all around radiator). Pin holes in hoses are sometimes hard to find.

 

[Kernal]

You could send a used engine oil sample off to Blackstone Laboratories for an Engine Oil Analysis (EOA), that should tell you if there's any coolant in the oil.

Blackstone Laboratories Blackstone Laboratories

Learn what's going on in your engine with oil analysis. Our free kits are easy to use and we explain the results in plain English!

www.blackstone-labs.com

 

[Stecz]

Didn't think about the soapy water test, I should have done that. I just know that the motor was cold and nothing dripped on the ground. I'll try this.