Bar's Leak Swells O-Rings?

[rpn453]

Has anyone noticed any o-ring swelling after using Bar's Leaks? I put a bottle of Bar's Leaks Stop Leak in my mother's Sunfire GT 2.4L a few months ago to seal a small leak in a water pump housing gasket that would have required a lot of unpleasant work to replace, and it may have caused some o-rings to swell.

The car began leaking coolant heavily a couple of weeks ago and I determined that the problem was a broken water outlet - a plastic piece that splits flow from the engine to the radiator and heater core. It has an undersized pipe end (hidden under flange in linked picture) that fits into a larger hole in the block, and is sealed by an o-ring fitted on a groove in the plastic outlet. The outlet broke at the groove, and the o-ring is now so large in diameter that it's hard to imagine it could have ever fit tightly. The o-ring on the pressure cap is also much larger than it used to be and no longer fits snugly in its groove. I'll be replacing the pressure cap along with the outlet.

I wonder if the swelling caused the plastic to break? All the parts shops I called had it in stock, so it's a very common replacement item. That seems unusual to me considering that it would likely never wear out. So maybe they just break regularly and it was all a coincidence. Or maybe they fail whenever someone adds a product that swells o-rings. The only reference I could find to Bar's Leak seal swelling is a post on another forum from a poster called puzz1ed, near the bottom of this page:

Disappearing Coolant

There are many positive comments from Bar's users on this site and this particular problem - if it's even caused by Bar's - is unique to this vehicle. But I don't think I'll be using this sort of product again. In hindsight, a day spent swearing at that car wouldn't have been so bad if it fixed the problem properly without side effects!

 

[JHZR2]

liquid bar's leaks?

Ive used the powder as a maintenance item in some cases and have not seen issues. I do not know the chemistry of the liquid.

 

[rpn453]

This is what I used (the smaller bottle):

http://www.barsleaks.ca/Products.aspx

It's liquid, but it also has pellets in there.

I experienced o-ring swell in the cooling system one other time. My dad had put some sort of coolant-life-extending additive in the coolant of the Grand Am I once had, and the next time I pulled out the thermostat (it had the style where you could remove it in about ten seconds), the o-ring was ridiculously long. I'd have thought someone had somehow managed to stuff the wrong one in there, but since it was impossible to get it back in, I figured it had to have swelled. It was oversized even more than the ones on the Sunfire. Next time I'm at my dad's, I'll have to see if he has any more of whatever that was. I don't think it was Bar's, and I don't think it was a stop-leak product.

 

[cparksjr]

Was this Bar's product purchased in the USA or what country? I work for the company that produces the product in the US, but we have different franchises around the world for this product. Would like to get some more info on this as we have not seen any issue and the materials in the Bar's Leaks should not cause any swelling of the rubber. The only time we have seen this is if engine oil gets into the cooling system like if it has a bad oil passage, head gasket leak, etc.

 

[vxcalais]

There is no way for the bars to swell the seals. Its not like an oil stop leak with seal swellers. The bars has the pellets in the fluid, it will clot where the leak is and the fluid puts a light film over the internals to help with corrosion etc..... Its a universal product and not many cars i imagine have rubber in the cooling system apart from the hoses.

 

[rpn453]

It was purchased in Canada. I had to go to the Canadian site to find the exact bottle online.

I'm curious enough that I'll probably spend the four bucks and drop a couple of o-rings in to see what happens. I'll report back on what I find.