holts radweld, bars seal, etc

The Rover fraternity, who have some experience of leaks, recommend K-Seal if you are going to resort to gloop. I have used it in the past with satisfactory results.

Andy C

I would avoid using it. A piece of white bread stuffed into the leak from the outside works amazingly well, or a bit of bodyfiller, depressurizing the system will enable you to go much farther between top ups. I have driven home on several occasions by leaving the cap loose and filling up every few miles.

Unlike almost all the others it goes in the cooling system with antifreeze. Most others will gel with antifreeze so need the system flushing before use and flushing after you think it fixed the leak to put antifreeze back in. It's easier to fix the leak than go though all that messing about.

K-seal just goes straight in and can stay in until the coolant is changed. Also K-seal is block and head gasket sealer too, Radweld won't do that.

Rover when they were Rover recommended Bars Leaks.

Fred gurgled happily, sounding much like they were saying:

Yes. They're all unspeakable bodges fit only for use on a car that you're running into the ground.

Weren't they the same people that designed the gaskets ? ;-)

No - they were BL by then.

That must be why my local Vauxhall dealership uses the stuff that goes in the expansion bottle! The additives do not work well on older cars, they can dislodge corrosion and glue them together. This will ruin the heater matrix. You are best just trying to locate and repair the original fault.

Thanks, loved it!

Not in my experience. I've never had any problems with Radweld.

Rob Graham

Didn't know that, but it's the one I prefer, rather than Radweld. Mike.

Can you please just change your name to 'Tiscali Idiot' and keep it that way?

Rob Graham gurgled happily, sounding much like they were saying:

Their whole purpose is to mask small problems.

Trouble is, masking small problems doesn't actually do anything other than delay the inevitable - whilst also ensuring that that day is bigger and more expensive when it comes.

It was certainly their choice for things like the P6 3500 which had an ally engine and copper rad, so shouldn't damage those materials. Dunno if modern engines have much more restricted water passages, though. If that makes a difference.

AFAIK When Rover was Rover K-seal didn't exist in UK market.

Techsheet of Bar's Leaks old product.

"WARNING - Head Gasket Repair is NOTCOMPATIBILE with antifreeze and must onlybe added to cooling system and radiator afterALL ANTIFREEZE has been removed." You want to try that on cooling systems that have small bore hoses for turbo cooling? Or water/oil oil coolers? Or throttle body anti-icing?

Bar's have had to respond to K-seal by developing a new product (the product index sidebar says *NEW*) that doesn't need all that faffing about draining and flushing the system.

and this one appears to be close to K-seal as it's also antifreeze compatible and got copper in it. But you won't find Bar's Leaks head gasket fix or K-seal at Halfords.

I think it is mainly the reduction in the size of the holes through radiators/heaters that is the problem, finer holes mean better heat transfer and smaller elements, but the anti leak additives block up those fine holes. Suzuki used to specify the thing that looked like a dog turd to be added with a coolant change on the old tea kettle GT750 two stroke triple (1970 ish) same stuff as Vauxhall used to provide.

I wasn't intending using any long term. There was another thread where someone mentioned their radiator being more likely to get a hole in that their tyre, so I was thinking more about a get-me-home-and-then-I'll-fix-it-properly type of use. If some brands require the system to be flushed first, then these would not be suitable for the kind of roadside, away-from-home, repair I was thinking of.

Fred gurgled happily, sounding much like they were saying:

How do you suggest cleaning it out...?

The kind of cooling system problem they "fix" is the kind that can easily be emergency-managed by just topping up regularly. If it's a big and sudden leak, the kind that will prevent you proceeding, then they're useless anyway.

Big enough leak, and that may not be a problem. :-)