I had the housing replaced two years ago, and we had to do the install twice because the base gasket/o-ring did not seal the first time. It's developed a small leak again at the base. Has anyone used a stop leak product in the cooling system with successful results?

 

I had similar problems. It didn't even last 2 years I think. When I replaced it I got two O rings of equivalent diameter and packed one on top of the other in the groove. It's lasted at least a couple of years so far on an aluminium housing.

Sorry no experience of sealants for this but I've used K sealit for other cars and it seems to work well for leaks. There's always a potential problem of blocked waterways I suppose.

The bent spanner end at 90 degrees trick helps remove the housing without lifting the manifold. I heated mine with oxyacetyline first to help bend it without it fracturing.

Regards
John

 

Opinion is usually divided between those who swear by 'stop leak' products and those who swear at them. I'm firmly in the second group.

The leak on the thermostat housing base is probably due to uneven tightening of the bolts or a warped base. You might be lucky with 'stop leak' but resolving the cause is a better approach than gambling on a quick fix.

Just my opinion and no doubt you'll get plenty suggesting the exact opposite!

Graham

 

There were a couple of warnings on either this forum or the XJ forums suggesting that you could plug the heater core with stop leak type products.

 

Why not just use a bead of the black Permatex sealant? They use the stuff on just about everything on a car.

 

Neither advocating nor condemning stop leak products, just passing along a little info: They work by curing when exposed to oxygen. As they pass through a non-sealed area, oxygen causes them to harden once they have piddled through to the atmosphere. They definitely do NOT cure in the middle of a radiator or heater core unless there happens to be oxygen present, so be sure to fill the system completely when using.

Personally, I'd like to have a few words with the dipsxxt that dreamed up Dexcool in the first place, followed by all the decision makers at GM (read: God's Mistake) that approved its production. Well, there are also several other reasons... ;-) It seems to weep through the smallest joint, leaving a nasty, crusty mess. There are other extended-life coolants out there that don't have those poor habits, I'm always perplexed as to why any OE would specify its usage in their product.

 

When I changed the tower and the thermo out the previse owner or indy used stop leak and a gasket sealant. What a mess had to flush the system several times. And yes they used dexcool by the tickets in the maint. file. It took longer to clean than replace the tower. I did take a square and checked the tower and it was warped. I asume thats why they used sealant. Had to make 2 bent 8 mm wrenches due to them rounding the bolts. I would change the tower if you are planning on using a sealant, if you add it to the out side of the tower it will blow out. I hate to to the job twice. Jim