Pressure testing cooling system

[megadave]

SOLVED* - turns out I was just using the wrong adapter. There's a couple that screw on fine but the one that seals the overflow hole had to be used

So I loaned one of those pump and adapter coolant leak test kits from AutoZone. Thought it was as simple as screwing the adapter on and pumping, but the pressure won't build.. Anyone have any tips on doing this properly. I have the adapter screwed on very tightly so not sure where the air is going. I suspect maybe it's leaking out the overflow but not sure exactly how the coolant expansion tank works..

 

[CoHPhasor]

You should hear the air escaping from wherever it is leaking.
Coolant overflow tank? Out of its tube
cylinders? through the spark plug hole
etc

You can use a tube like a doctor's stethoscope to hear in hard to reach places.
There will be plenty of youtube videos on a coolant leak detector

 

[megadave]

You should hear the air escaping from wherever it is leaking.
Coolant overflow tank? Out of its tube
cylinders? through the spark plug hole
etc

You can use a tube like a doctor's stethoscope to hear in hard to reach places.
There will be plenty of youtube videos on a coolant leak detector

Thanks for your reply. Turns out I was just using the wrong adapter from the kit

 

[Frankh]

SOLVED* - turns out I was just using the wrong adapter. There's a couple that screw on fine but the one that seals the overflow hole had to be used

So I loaned one of those pump and adapter coolant leak test kits from AutoZone. Thought it was as simple as screwing the adapter on and pumping, but the pressure won't build.. Anyone have any tips on doing this properly. I have the adapter screwed on very tightly so not sure where the air is going. I suspect maybe it's leaking out the overflow but not sure exactly how the coolant expansion tank works..

Yeah partly why I built my own.. Its the same thing I use for boost leak testing. Mine has a 5/16ths rubber hose that I connect to the top of the expansion tank. Then I plug the end of the hose I disconnected. That way you are testing the existing pressure cap as well.