is 13psi good enough to find leaks...

Pump it up and see if she leaks down. Is that all your gauge reads up to? I would think 25-30 would be more likley to show a leak.

Mazda suggests 20psi and looking for leakdown.

anything over 20psi is a bit dangerous, considering your coolant system probably never sees more then 18psi when functioning properly. normally if you have a leak pump it to anywhere from 15-20psi if the needle starts dropping you have a leak somewhere (internally or externally) also make sure to clamp the hose to the coolant reservoir.



kevin.

An internal leak would mean shot o rings correct? The coolant from my overflow bottle is not being sucked back into the engine. I already replaced the ast cap and the hoses for the ast. I guess I'll have to pressure test mine.

I'm adding this chart because I think it shows where the coolant might leak.. Its the flow of the coolant system (got it from the 7club).



[attachment=39957:attachment]



Some of the unusual hard to find leaks migh be from the motor to TB, TB back to WP (2 rubber hoses and 1 hard line). also, I've hear people loosing coolant thru temp sensor not being on tight, AST leaking, etc.



Make sure to see the chart and where there is a clap, check to see if you feel any wetness.