Is it safe to use radiator stop leak?

[ClarencePeters]

My radiator is leaking pretty badly and needs replaced. It usually doesn't seem to leak until it builds up pressure and then after you shut it off it keeps leaking for a few minutes then stops.

[Jim Cate]

Originally Posted by ClarencePeters

My radiator is leaking pretty badly and needs replaced. It usually doesn't seem to leak until it builds up pressure and then after you shut it off it keeps leaking for a few minutes then stops.

RAdiator? On a boat? Maybe you should give us a bit more info, Clarence... this is kinda vague.

Jim

[faragaki]

AlumAseal radiator sealant worked best for me. But this is a last resort action to be used in an emergency only. It is a temporary fix to stop small leaks usually at the expense of of your pump bearing. Eventually, the leaks will continue to grow and the whole thing will blow. After repair, radiator, freeze plugs and whatever else is needed, try to remove as much of the sealant with a good backflush. DO NOT use the goop type sealants as these are nearly impossible to clean out and will clog everything. Good Luck and remember, sealant is a temp repair, you need to fix what is broken!

[valhalla360]

As a stop gap measure until you can get it fixed right...sure.
As a long term solution...no

[GordMay]

Greetings and welcome aboard the CF, Clarence, and faragaki.

[Sailmonkey]

Radiator?

Are you sure it’s not just an o-ring on the heat exchanger that needs to be replaced?

[pcmm]

Originally Posted by ClarencePeters

My radiator is leaking pretty badly and needs replaced. It usually doesn't seem to leak until it builds up pressure and then after you shut it off it keeps leaking for a few minutes then stops.

If you can, post a picture of your "radiator", in 35 years of sailing I have yet to see a radiator on a boat as part of the engine's main cooling system.

[Siberian Sea]

I suppose your talking about a leak in your heat exchanger, anyway suppose you use this stop leak crap in your engine and the leak stops..... then one day your motoring down some narrow channel fighting a strong current or headwind, suppose your passing under power through some tight pass in the reef to get inside the lagoon..... well often as is the case this is when your stop leak fails and your engine gets hot because the coolant is gone. But I would wonder just what type of hell this stuff might have on other things like your thermostat, water pump bearings, or temp sensors. Might behoove you to just get out the toolbox and fix the leak as to prevent an even greater headache.

[oleman]

Originally Posted by ClarencePeters

My radiator is leaking pretty badly and needs replaced. It usually doesn't seem to leak until it builds up pressure and then after you shut it off it keeps leaking for a few minutes then stops.

We have a old perkins 3.152 in a ford dexta tractor with a cracked block to the outside due to freezing 10 years ago. Not repairable but usable with oatmeal based radiator sealer believe it is Barrsleak. When you have a bad coolant leak leave off the pressure cap, watch the temperature and keep coolant handy. This tractor has mowed our property in Pensacola Fl for years in this condition.

[foufou]

Don't do it. Most of the stop leak products will clog something in your cooling system. I recently tried such a product and clogged the radiator. Go for tbd real fix

[hellosailor]

Those stop-leak products, all of them, are designed really to "get you home". At that point you may have clogged any and all parts of the cooling system, not just the radiator. The generic trick was to pour sawdust into the coolant, that'll stop leaks too.

The only problem is, it may upset the coolant pump, start clumps that clog cooling passages, and of course it is never a permanent reliable repair. Just makes for more work, more need to flush things out, when you do have to make the real repair.

But, great if you need to "just get home".

[Greg Mason]

A solution could also be an egg or black pepper, neither of which will punish your engine parts you don't want to be affected.

[mikeod]

There is a stop leak that gm has been putting in New cars on the assembly line for many years to stop nuisance leaks. Cadilac recommends adding it whenever coolant is changed. Can't remember the name I would have to dig it out. Its a tablet of compressed material. It may have been by bars leak.

[Madehn]

well i used almuna seal on my water cooled motorcycle radiator (750 suzuki - the old water buffalo) and rode it for another 40K miles with no issues- it worked for me and caused no other problems. i used the whole cannister if powder which was probably overkill given that it was designed for a car and this was a much smaller cooling system.-- it worked fine and the bike had zero leak or over heating issues in the years following.

[Capt Gill]

Originally Posted by ClarencePeters

My radiator is leaking pretty badly and needs replaced. It usually doesn't seem to leak until it builds up pressure and then after you shut it off it keeps leaking for a few minutes then stops.

What kinda car ya got ? I used some stop leak on an old aircooled VW bug as a preventive measure, never had a problem.