K-Seal - Yea or Nay?

Ethan5150 · Post by **Ethan5150** » 22 Apr 2024, 18:46

Hi folks, I recently "fixed" my radiator neck on my 2006 S60R using this excellent writeup by Mikele82: viewtopic.php?t=90098

It worked for a while, but now I'm getting a tiny leak that appears to be coming from between the copper pipe and the original radiator neck.

I went back in this weekend and applied more high-temp JBWeld to the inside of the radiator neck but I did NOT pull the copper pipe out and try to re-apply the epoxy the the outside of it (and the inside of the neck) - my thinking is that the copper pipe is essentially in there permanently at this point and pulling it would probably be impossible, or cause further damage. Anyway - after re-gooping the interior of the neck, the leak seemed to go away, but now it's back again only a couple days later. I'm debating whether I should try again or use some K-Seal stop-leak additive. I've done a LOT of reading on stop-leak additives in general, and K-Seal in particular, and there are a lot of different messages.

So I'd like to hear your opinions. I'm broke - that's why I'm not just replacing the radiator. My thought is to maybe just add like a quarter of a bottle of the K-Seal and see what happens? I'm concerned about all the costly side effects I've read about but it seems like a lot of people have had pretty good experiences with K-Seal too. So how about you? Anyone who's had experience, can you speak to this dillema?

Thanks in advance - I look forward to hearing your thoughts.

- Mahalo,
Ethan

Post by **jonesg** » 22 Apr 2024, 19:21

i would replace the radiator.

Post by **BlackBart** » 22 Apr 2024, 21:43

Could you use that to limp it along until you save up enough for a new radiator?

Ethan5150 · Post by **Ethan5150** » 22 Apr 2024, 21:56

Well, it's such a small leak, I was thinking just a small about of the K-Seal would do it. I drove around today for like 20 minutes and it didn't leak at all. But the other day I did some highway driving for a while and then noticed it had leaked the next day - maybe a quart or so. So yeah, I guess the question is; just how bad for the cooling system is the K-Seal? I'm also thinking I might just try wrapping the radiator neck with some Rescue Tape, which I've had pretty good success with in the past. Maybe I'll try that first...

Post by **MoVolvos** » 23 Apr 2024, 07:34

.
Most sealers work to plug rather than as an adhesive. The neck is too flexible so won’t work well. In the head gasket or the radiator body it might work depending on the severity of the leak. Unless you degrease and rough the surface, adhesives won’t provide a good chemi-mechanical bond either.

yanga001 · Post by **yanga001** » 24 Apr 2024, 09:32

Ethan5150 wrote: ↑22 Apr 2024, 21:56 Well, it's such a small leak, I was thinking just a small about of the K-Seal would do it. I drove around today for like 20 minutes and it didn't leak at all. But the other day I did some highway driving for a while and then noticed it had leaked the next day - maybe a quart or so. So yeah, I guess the question is; just how bad for the cooling system is the K-Seal? I'm also thinking I might just try wrapping the radiator neck with some Rescue Tape, which I've had pretty good success with in the past. Maybe I'll try that first...

My recommendation would be to get a new radiator or pull a used one. I've used head gasket sealers to great effect but i do not know if i would recommend it for a rad leak. If you have a partial failure in one spot then chances are that more failures will emerge elsewhere. Remember that this is a pressurized system, so any other weakpoints in the rad will begin to show up once you do that spot patch.

When i used head gasket sealer, i installed a newer radiator (from my wrecked wagon with maybe 30-40k km and 5 years old on the rad) so i knew i did not have issues there. The sealer also fixed a small leak in my heater core but then i undid all that work when the engine froze in -30C on the highway. This was due to not getting the coolant concentration correct.

Point is, the head gasket sealer is like fixing wire insulation with electrical tape. Yes it may work, but the better method would be to replace the section that has damaged insulation.

EDIT: Saw your situation

If this is an automatic then you should be able to pull any rad from like a 99 S80 - 07 V70. https://www.fcpeuro.com/products/volvo- ... -1#fitment

If its a manual, and you want to be hooptie then you may be able to fit in a different make and model rad as you will simply be using it to cool the engine. Volvos are very very very sensitive to overheats so i would not mess around to much here.

Id say things that kill these engines are:
Timing belts
Overheats
Neglected oil changes/breather systems