Coolant Reservoir Leak '87? - '91

[mrdap]

Hello All,
Anybody else struggling with coolant reservoir leaks?
On the later models, I think it started in '87? and went to '91.
They're mounted on the top of the right hand fender well.
I have a continuous leak from the front mounting tab.
I replaced this reservoir so many times I lost track.
I've gone through at least three NOS GM reservoirs, when they were still available.
And they all leak when new.
Apparently the supplier had some kind of problem near the tail end of their production.
I tryed a repro. from LMC.
It It didn't leak for a short time and then it started leaking in the exact same place.
Has anybody solved this problem?
Or have a source of reservoirs that don't?
Thanks in advance.
DAP

 

[nvrenuf]

I replaced the one on my Blazer with a new GM a few years back but it started weeping down the fender liner about a month after I got it. After reading a lot of similar feedback I replaced mine with a 2 qt billet aluminum tank from Amazon. Ultimately, with the tank, AN fittings and molded hose I spent just over $100 when there are a plenty of less expensive universal tanks, I just didn't like them.

After I had installed my tank I saw pics where a guy installed an OE coolant tank from an 88+ gmt400. He mounted the tank to the fender next to the core support, it looked almost like it was original (to the square body).

 

[SirRobyn0]

I was going to suggest the same thing that John has done. Replace it with an aftermarket. You can get aftermarkets in plastic to, and you can relocate the tank if desired.

 

[SquareRoot]

LOL. I just replaced my factory one with an LMC unit about a week ago. It seemed the issue with the OEM one was that the corner was pressed together, like folded over like a taco and it eventually split apart slightly. Now that I see this is somewhat common I'm going to do what I contemplated earlier. Empty it, clean it out and fill the inside corner with epoxy. If its solid, it wont leak!

 

[85 Squarebody76]

I repaired mine with JB Weld on and around the tab outside of tank while it was mounted on the fender well. has not leaked since. That way it was stressed (bolted) to fender well.