Radiator pressure test 04 GTP

[Comp04]

Losing coolant but can't find the problem. Picked up a pressure tester but when I try to pump it up the air escapes through the recovery tank without any resistance. Are you supposed to pinch off that line to bypass it? The tank and radiator are both at their correct levels. What am I doing wrong? 2004 Grand Prix GTP with CompG.

[Scottydoggs]

seems like the pumps not seating right. is there a different cap part you can use with the tester?

[Comp04]

I have the adaptor for the screw on radiator cap but that is all there is.

If I pinch off the bypass hose pressure will start to build.

[Scottydoggs]

pinch it off, or a bolt and hose clamp should seal it good. never heard of this tho, it should seal off tight.

[Comp04]

I'll be trying that in the morning.

Thanks for the reply.

[ericspecullaas]

Also keep in mind that the pressure should hold perfectly still once you stop pumping it up. It should hold pressure perfectly forever but I would hold it for 5 mins.