Proper procedure for finding coolant "leak"?

[flyhop]

The coolant reservoir never has any pressure in it and has run low on coolant a couple of times in the last 8 months. What is the proper method to test for a leak in the coolant system? And how can I test to see if it's the reservoir cap that's not sealing?

2000 SL2, Auto, 125m miles.

[kwayne4588]

I have always used a coolant pressure test kit. You can rent them from your local autoparts store. O'Reilly's rents them for 149.00 but you get your money back when you return it.

But I don't know if the kit will have the adapter to fit the Saturn. If it does you simply pressurized the system and if there is a leak it will force the coolant out at the leak's site.

Maybe someone will chime in on the max pressure for the Saturn, for my Honda ACE it is 20 psi.

[fdryer]

15psi max. If your local auto store doesn't have one to borrow you can always tape napkins around the coolant reservoir temporarily as long as it doesn't rain; if coolant actually flows out a leaking cap the napkins will stain. Inspect the radiator side tank where xmission oil cooler lines flex for coolant stains, hoses and water pump.