: Expansion tank leaking...



Wicho
01-29-06, 08:13 PM
THe "Check coolent level" warning came on and after it cooled I start tooling around to see where the leak was coming from. I found that right next to the expansion tank cap there is a hose that goes down into the motor. I am new to car and this is my first car and don't know what that hose goes. Anyways it is leaking. I filled the expansion tank with coolant and it slowly rose until it reached the hose outlet and leaked out through there. Also I noticed that the radiator hose is very soft and when I squeezed it the coolent would raise quicker like as if I was pumping with the hose. Can anyone help me out ? This is a 97 deville with 97k on the clock.

Ranger
01-29-06, 08:33 PM
Just had the same problem on my previous car ('97Deville) last summer. The hose you are looking at is the purge line. It runs to the water pump housing. The official fix is to R & R (remove and replace) the surge tank. I was able to repair mine and it is still holding. If you want to give it a try (you have nothing to loose) scuff up the area with some sand paper. Then mix up some JB Weld and apply it to the crack. Build it up a little and then let it set for 24 hours.

Wicho
01-30-06, 12:52 AM
The expansion tank itself is not leaking. THe coolant rises to the hieght of the purge line and it goes all the way through the purge line and leaks. Could it be it came loose ? I really have not idea:suspense:

94greencaddysls
01-30-06, 01:30 AM
It's hard to help out without more specific's. Do you mean the purge line out the side of the expansion tank or the small hose that runs down from the pressure cap? You should not be filling the surge tank to the top or you will get leakage out of the expansion tank drain.

jupiter57
01-30-06, 10:25 AM
Personally, I would take no chances!
I would replace the surge tank, all hoses going to it, along with each and every other coolant hose, pressure cap, etc. Sure, it will cost a few bucks now, but my feelings are that improper coolant system maintenance is the leading, if not #1, cause of head Gasket failure.
When I bought a '97 DeVille last year, it had the symptoms of a blown head gasket. I tried a few shadetree methods before removing my radiator and having it flushed and "rodded out".
Before I put it back on the road, I changed every single hose on the engine. Still going strong 6 months later.

I am of the notion that the Northstar should be meticulously checked & maintained, cooling system wise, and if properly maintained, you should have practically no problems!
Too many 200K - 300K mile Northstars out there!

Wicho
01-30-06, 12:19 PM
I am talking about the hose coming out near the expansion tank cap, not the on near battery.

Ranger
01-30-06, 12:20 PM
The expansion tank itself is not leaking. THe coolant rises to the hieght of the purge line and it goes all the way through the purge line and leaks. Could it be it came loose ? I really have not idea:suspense:
The flow is from the water pump to the tank. How do you know the level is rising? There is always coolant in that line. In my case the crack was so fine, that it was not visible unless it was under pressure. Inspect it closely. It is not likely that the clamp came loose but you could always tighten it a bit.

Wicho
01-30-06, 01:21 PM
I know the coolent is rising because I turned on the car without the expansion tank cap on to see if it would loose coolent. THe coolent rose high enough to escape through the line near the cap. The hose is just loose and goes down into the motor somewhere and is not connected to anything. Is it supposed to be connected to something ? PLEASE HELP:crybaby:

Wicho
01-30-06, 05:22 PM
Found the leak, it's coming from the line that is near the battery. Actually it is the expansion tank. The little nipple has a hair line crack that when I rev the engine start squirtting the coolant. I am going to just buy a new hose, jb weld it and be done with it

Ranger
01-30-06, 06:17 PM
I know the coolent is rising because I turned on the car without the expansion tank cap on to see if it would loose coolent. THe coolent rose high enough to escape through the line near the cap. The hose is just loose and goes down into the motor somewhere and is not connected to anything. Is it supposed to be connected to something ? PLEASE HELP:crybaby:
Now I am not sure which hose you are talking about. The hose from the filler neck goes over the side and just ends. It is an overflow drain. The hose from the surge tank that runs across the engine (under the silver beauty cover) to the pump housing is the purge line. that is the one I am talking about and assume you are as well.

BTW, if you run the engine more than about 3-4 minutes with the surge tank cap off, it will start to overheat and spill over the filler neck.

Wicho
01-30-06, 09:15 PM
My quick fix did not work. I guess I am going to have to get a new expansion tank. How much can one run for ?

Ranger
01-30-06, 10:40 PM
Like I said, you must clean and scuff up the area good, and MUST allow JB Weld to set up for 24 hours for a good bond. No idea on price.

Wicho
01-31-06, 03:53 PM
The tank is finished breaking on me:banghead: . Where other then the caddy dealership can I locate a NEW tank and how much would it run for ?

boricuacaddy
01-31-06, 04:04 PM
Is this compatible with a 97 Deville? I would think so, because it is a northstar engine but not sure..

http://cgi.ebay.com/ebaymotors/96-Cadillac-Seville-STS-radiator-overflow-tank-used_W0QQcmdZViewItemQQcategoryZ33602QQitemZ803387 7158QQrdZ1QQsspagenameZWDVW

David

Wicho
01-31-06, 04:25 PM
Thanks for looking boricua but I would rather buy new just to be absolutly sure this will not happen again. Can someone get the part# for the tank ? Thanks everyone.

94greencaddysls
01-31-06, 07:15 PM
Part number is "3540041" Gmpartsdirect lists this for 58.59 shipped and it is not special order.

Wicho
02-06-06, 06:50 PM
I am having trouble removing the broken tank. I removed the visible hoses but there is a hose hidden under the "a/c canister" that I can not seem to remove. I already loosened the clamp but the clamp on that hose but the clamp has a bolt in it or somthing and that is the reason I can not get it loose. Should I just cut the hose and buy another one or try and play with it until it comes loose ? Thanks

94greencaddysls
02-06-06, 09:52 PM
that hose is the main supply to the system from the tank. I used wd40 and a bent screw driver. sprayed it and worked the screw driver in and around to break the seal. The bolt that goes through the hose is only there to keep the hose clamp in position