Small coolant leak in/around expansion tank (PICS)

[ljbrandt]

So I recently changed the coolant on a '04 Impala 3.4L. While doing so, I removed the coolant overflow tank (non-pressurized) and tried and clean some of the brown gunk (dried dexcool) out with a garden hose. When I reinstalled and connected the tank, I noticed that it was leaking very slowly from the very bottom, maybe one drop every few mintues or so. I took the tank back out and inspected it very closely and could not find and holes or cracks. I assumed then that the leak must be coming from the connection between the hose and the tank...so I made sure to take some pliers to the snap ring clap to tighten it as much as I could. The leak seemed to go away, but after about a week, I put my hand underneith the tank to check if it was dry and to my dissapointment, I felt a thin layer of coolant. Aaaarhhh.

This weekend, I decided I would get to the bottom of this! Yes I could spend $50 and replace the tank and hose, but this is now about principle...

Anyway, yesterday I took the expansion tank out of the car again, emptied and cleaned it and then filled it with some water and added some green food coloring. I hung the tank up on a flower basket hook outside and took a magnifing glass to look over every inch of the tank for leaks - even after 24hrs nothing! Not a single drop or even a hint of a leak.

Going back to square one...I'm guessing the leak must be comming from where the hose is clamped to the tank. But last time, I used all my might to tighten the plastic clamp with pliers, but I guess it still didn't seal 100%. Would something such as WD-40 sprayed in the rubber hose allow it to seal better with the plastic nipple it slides over on the expansion tank? If not WD-40, any other ideas? Here are some pics I took from yesterday...

tank on hook

up close

up close #2

up close #3

hose and clamp

 

[Boomer]

Couple thoughts:
1. Is the hose long enough to cut off an inch and reinstall? Old piece my be stretched out and cracked.
2. Try a SS worm gear clamp. Might be tighter.
3. Get some white Teflon filled plumbers putty and smear it around the plastic nipple on the tank and reinstall the hose.
4. Use all three ideas above together.

Avaoid any petroleum based stuff like WD-40 on rubber as it will cause the rubber to swell and eventually soften and crack.

 

[hemitom]

I would start with a better clamp.

 

[ljbrandt]

Thanks for the great suggestions. I'll get a SS worm drive clamp and some teflon paste!

Something like this?

or could I just use a bunch of teflon tape I have on hand to save some money. Otherwise gotta make a trip to harbor freight & home depot.

 

[The_Eric]

You don't need sealant. Snip 1" or less off and use a better clamp.

 

[1kickbuttranger]

I'm with Boomer and Eric.. Cut a bit off the hose. I'd use a little spring clamp- the factory one will work as well.

 

[ffhdriver]

Don't be so cheap, buy a new hose.

 

[RH+G]

I have used a ziptie in place of small clamps

 

[Digital2k2]

We have the same tank on the 06 lacrosse. Ours leaked where the plastic is thicker behind the hose connection. Where the coolant is forced down before it can go up to the hose. It got a hairline crack from removing the hose to clean it. I filled the whole gap on both sides with epoxy and *knock on wood* it hasn't leaked since.

While you haven it out, it'd be a good idea to reinforce that part of it even if your leak isn't coming from there.

Edit: Our tank has a metal clamp. It really leaves a deep indention on the hose and makes for a very tight seal.

 

[ljbrandt]

Update:

Well, I took off about 3/4" of the hose end, wrapped teflon tape around the nipple and replaced the plastic hose clamp with a SS worm drive clamp (from NAPA). I'll let you all know if it works...and maybe now I can get some sleep at night because this leak has been driving me crazy for weeks now.

Didital2k2, thanks for the heads up - I'll definitely keep an eye on that spot!

 

[ljbrandt]

It worked! The leak was being caused by the cheap plastic hose clamp. With the stainless steel hose clamp, it's been three weeks and dry as a bone!