: coolant leak

08-06-09, 09:20 PM
I have a strange one, I had my rad changed about a month ago and I have had to fill the overflow 3 times now. I took it back and they did a pressure test and all is well. No leaks anywhere. I have had the car checked for gases in the coolant just in case it was my headcasket and all is clear. I use about 1 gallon every 2 weeks. Car is running great and no overheating on the highway. Stays at 196'. Anyone hazzard a quess?

08-06-09, 09:36 PM
:)water pump they leak just befor they fail. My 3 days of owning a rare 1986 devile convertable has me installing a new one at no small expence.:(

08-06-09, 09:42 PM
You are leaving 2" - 2 1/2" of air space in the tank aren't you?

00 Deville
08-06-09, 09:42 PM
I had my rad changed about a month ago and I have had to fill the overflow 3 times now.

How much coolant would you estimate that you added in the past month?

Sometimes these cars will pass a short pressure test. Here's a couple of options to try....

Slide a piece of cardboard under the car when you park it overnight and see if you have any spots from leaks on it.

If you don't... borrow a pressure tester from an auto parts store... some will loan you one for free. Pump up the recovery tank to 15 PSI let it sit overnight or longer and check the cardboard for leaks again.

I had a slow leak on both my 2000 and 2002 that would only leak occasionally and would evaporate on a hot surface before hitting the ground. They would pass a short pressure test (couple of hours) but would fail an overnight check. Both of them ended up being the water pump cover gasket.

08-07-09, 04:20 PM
Not exactly sure what to say except for this. If you do end up doing a water pump job, not sure how much of a difference there is between your car and my 95 deville but when you do the water pump, or the water pump gasket, once you pull that pump off for either or, change the water pump inlet gasket. If you dont, you will put the pump back on bolt everything down and begin to fill her up when you notice you are pissing water from the water pump inlet gasket. :( It happened to me. Just giving the heads up.

08-07-09, 05:11 PM
The coolant has to be going somewhere. Note that if you do a test for exhaust gases shortly after adding to or changing the coolant in the recovery tank there is a -chance- you may get a false negative from that test. 3 times in a month is an awful lot of coolant if you aren't overfilling (see Ranger's post above).

08-07-09, 09:30 PM
No, I am not over filling, 2 1/2" left. It is now losing about 1/4 gallon in 2 days. Checked the oil and antifreeze, they looked good. Drove from Brampton to Pickering and back (180 km) not overheating at all. Stays @ 196 even. No smoke. I will try the test again as well as Monday morning take it to my mech. and have him do the test as well as an overnight pressure test. If you can think of anything else. I will keep you posted.

08-07-09, 09:54 PM
Northstars don't put coolant in the oil so don't bother looking. It's probably a small leak that evaporates before it drips. Radiator side tanks are a common leak point.

08-07-09, 11:11 PM
It is a brand new rad, would I still get a leak from the side?

08-08-09, 10:15 AM
Not likely.

08-09-09, 12:53 AM
Thanks Ranger. I was having the same problem. I'm new to Cadillacs.Just bought mine two weeks ago. So i was over filling it! makes since because the two times I filled it and would go driving and then park I would smell antifreeze. thanks again! I'm learning everyday.

08-10-09, 01:06 PM
I could not find my last post as it was moved, so I hope it is ok to start a new one. I took my car in to my mech. today as it was losing coolant. If you remember 1 quart a week. It is not overheating on highway as it always sits @ 196 degrees. We did a gas test last week and it came up negative. My mechanic put the probe into the radiator and got a reading of over 700 (He said it should be near 0). Now my question is, does anyone know of someone who can do a head casket job. I live in Pickering Ontario Canada. I can not afford to go to the dealership for this. The car is mint so I do want to keep it.

08-10-09, 01:10 PM
Head gaskets are expensive (95% labor). Try your local corner mechanic but they are most likely going to be the same as the dealer. Most places go by a book that quotes how many hours a job should take. I'd recommend that you do it yourself. It really is not that hard and you will learn a lot from doing it.

08-10-09, 01:25 PM
...............or you could contact your Canadian neighbor at www.northstarperformance.com

08-10-09, 02:26 PM
:(Does no one know onyone closer, they are down by Detroit, 8 hours away. I am close to Toronto.

08-10-09, 02:49 PM
Heard about a product called: Heal-a-Seal, don't know if it works or not. Not one to put stuff like that in my rides. Head gasket is pricey.
Try this place, maybe they know of a good Cadillac mechanic in your area.

08-10-09, 04:12 PM
Heard of Heal-a-Seal? Don't know if it works or not.
Personally I have never found a quick fix product that does what it says to do.

Check out this website, maybe they will know of a Cadillac mechanic in your area.

08-10-09, 04:36 PM
:bonkers:Just got off the phone from 2 dealers, they want 5,000 to 7,000 for head casket. This is in Pickering. Anyone know someone who can do this cheaper. I can not do this myself and I really want to keep it as it is mint and never seen a winter.

08-10-09, 05:17 PM
I would think a good casket would be cheaper than that, if all it needed to hold was a head.


08-10-09, 05:26 PM
I moved your last post to the Northstar section (where it belongs). I'll move this one there and merge the two.

00 Deville
08-10-09, 05:26 PM
8 hours away isn't that far to take it to one the foremost head gasket experts... He does them for $2200 and gives a warranty better than most places. I've heard that Jake has an arrangement with a company that will ship your car to him.

08-11-09, 03:22 PM
Check out local chapters thread(Canada), there is a guy in Tillsonburg(near Woodstock) named Jake at Northstar Performance.
Here's the website from there. Hope this helps.
P.S. I know its a bit of a trip(3hrs.) from Pickering(closer than Detroit) but the price is definitely right.