aggravation

I'm having trouble determining if my radiator or a hose is leaking and would like to try and leak check it without removing it if possible. (don't want to pull it until I have a replacement in hand)
How much pressure can I put on it at the reservoir cap without creating a problem?
I was thinking of using a piece of bicycle inner tube (with valve) clamped to the mouth of the reservoir....

Jim bailey - 928 International

try 15 lbs ,,,that is normal

dr bob

What Jim said...

You'll be hard pressed to get 15 PSI in there with the bicycle tube and hand pump method. The tube isn't that strong, and you''' have trouble getting a seal with the rubber around the not-smooth-or-round neck for the cap.

There are purpose-built cooling system testers that have a cap with a hose fitting, a hand pump with a relief valve, and the hose. Some parts places will loan you one with a deposit. They are a little steep to buy for one-time use.

I give thought every once in a while to modifying an old coolant cap with a threaded fitting. It maens the spring and the plunger are removed, and all the sealing is then done by the rubber top gasket, something it's not designed to do. If you do try something like this (or another way whatever that might be...) be sure to keep the pressure no greater than 15 PSI. Much more than that risks pushing coolant through water pump seals and also risks ruining coolant gaskets in places that are hard to see and harder to fix.

marton

better that you put the pressure in somewhere else because you will know when you reach 15lbs when the cap starts to release pressure; you can hear it.

Unless the cap is faulty of course, if it is then your system has experienced the over or under pressure

Marton

Tampa 928s

Go to Auto Zone they rent them for free!

Jim bailey - 928 International

Free is GOOD !

danglerb

Ones with a gauge are what, $10 or so? But free is hard to beat and no extra junk to keep around.

JHowell37

You've got a Porsche that is almost 20 years old. I assure you, no special tool you buy for it is a "one time use only" tool.

dr bob

These range in price up to over $100 for a full test kit. Make it to the Snap-On catalog and you are into small car payment land. Borrow one from the parts store, rent one, or have repair place do the pressuriazing for you with theirs. Finding a coolant leak may be a one-time use even on a 20+ year-old car. Most coolant leaks aare pretty obvious, except for those that aren't. Some only leak when hot and pressurized, somtimes a head gasket or the oil or trans cooler tube in the radiator is cracked, sometimes an end tank seal or a collapsed hose nipple on the tank. Worth having the $100 tool just in case it happens again? The seals in the pump and cap in the test kit will deteriorate about as fast as the ones in the car. My luck has me working on the tool for longer than it would have taken to fix the problem on the car.

danglerb

Coolant has a smell that my nose is tuned in on. When you smell the leak and can't find it, plan on it being expensive.