What to do if aluminum coolant tube cracked? (Page 1/1)
John W. Tilford OCT 28, 08:23 AM
(1988 GT with 1995 3.4 and 4T60, near Bloomington, Indiana) I hope this is a hypothetical question, but I can't find where a coolant leak in the passenger side rear end is coming from. Was not evident last week, then I saw a little stream of coolant on the concrete under the parked-for-several-days Fiero. Wiped it up. More leaked out. Wiped that up. No more. I thought, "What caused that? The car's not moved for days! Change of temperature?"

Months before that I was on my back looking around under the car and saw one little fresh glistening green drop on the top of a cradle member (seems like cradle in my memory, at least some strong steel member) just smiling at me with no pool underneath. Added a little coolant to the expansion tank.
This hide-and-seek leak has been going on for more than a year. Was first evident as a few drops/very small spot on garage floor. Rarely a stream flowing downhill toward the garage door like last week. That most recent unexplained on-and-off flow set the record for volume, and that was not much.

Car in shop this morning on another issue but I asked them to try to find the coolant leak. If it is a crack in the passenger side aluminum tube what can be done? Chewing gum? Fabricate a new tube? Anything in between?

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John W. Tilford

Gall757 OCT 28, 08:56 AM
The water pump is the most likely source. Coolant drops through a lot of parts before it hits the floor. The coolant tubes are stainless steel, and not prone to cracking.
John W. Tilford OCT 28, 09:01 AM
I didn't think of that! How obvious. I've changed water pumps in Chevy S-10s before, but I could actually see and access those. AND, so much for my aluminum theory. Thank you!
Raydar OCT 28, 09:51 AM
I have also seen the gasket leak, where the coolant return line connects to the timing cover. (Seems like the gasket that leaked was the timing cover gasket, and not the water pump gasket.)
Will OCT 28, 02:36 PM
The main coolant tubes to the radiator are stainless steel.

The heater tubes are aluminum, but have a reasonably tough epoxy coating. They're more likely to corrode than crack.

I agree that it's less likely the plumbing and more likely a waterpump or gasket, especially if those weren't tended to when the swap was done.
theogre OCT 28, 04:03 PM
Yup, leak could be WP seal or any engine gasket or hose and if your lucky is an easy to get at. Head gasket(s) can leak coolant too.
WP seal put a white rag or paper towel stuffed into the WP weep hole.

Weak coolant and electrical problems can cause whatever is leaking.
< 50% coolant = weak coolant = weak or no anti rust, WP seal lube, etc. additives.
Crap Ground(s) then coolant can often will be a ground path to the starter, alt and other things and eating everything including rubber hoses.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave