Morris Minor Owners Club

Someone please jump on this topic if what I'm doing is dangerous etc, but I've found that as a temporary radiator patch, ie to last a couple of days until you fit a new one (they didn't have any in stock) Cupernol miracle wood works wonders, it's a hard setting, water proof putty so you just squeeze it into the radiator around the leak and it seals it! I had wondered about putting radweld type things in but decided that as I was going to put a new radiator on I'd be happier without radweld floating round in the system.

yes - if you are putting a new rad on, then best to avoid radweld from bunging it up.
All kinds of stuff can be used for a temporary repair on a rad - I've used car body filler in an emergency.

If you want a more permanent repair then get hold of a high power soldering iron and solder the hole up. (that is sometimes done by the radiator reconditioning people, but on modern rads they just fall to bits so they have to fit a new matrix.)

Yes, I have done the soldering trick, but I used a blowlamp and some electronics type flux cored solder. Worked a treat!

I don't really agree with the Radweld solution as it gets everywhere and if it 'bungs up' your radiator then surely it's doing the same inside the engine block/head??

'bungs up' your radiator then surely it's doing the same inside the engine block/head??

I thought it only reacts & goes solid when it comes into contact with air??

I thought it only reacts & goes solid when it comes into contact with air??

If you get trapped air somewhere in the system like in the head or heater matrix, what happens?
I have used it but it does make me nervous due to the (low?) risk of side effects.

If you get trapped air somewhere in the system like in the head or heater matrix, what happens?

Who knows..... be interesting to find out though...

When I was a BT field engineer and there was any form of water leak the garage used to put a pellet of Bars Leak in the Rad and some vans had it repeated more than once over the years and I dont remember hearing of other problems but that might not be the case with Radweld and its counterparts.

I've also never heard of problems using Radweld on a Minor but as it can bugger up modern cars, it's probably worth to make people aware that it's not always a miracle cure.

as it can bugger up modern cars

Do tell...??

Its like antifreeze now being reccommended at 50% solution all year round even for Moggies as it will stop the corrosion of the thermostat housing and the heater valve and even the water pump if you have one of the modern alloy ones.

now being reccommended at 50% solution all year round even for Moggies

oops....

If you look at a Eurobox - something complicated like a Volvo turbo that has a sea of pipes etc.. that are steel and rubber it's possible to air lock a small pipe and the pipe then becomes fully closed off, assisted by the radiator sealant. (I've seen the end result).
I've also heard stories that some modern radiators have a very fine core which is not suitable for the big chunks of radiator sealant, so can get bunged up. I've not seen this in the flesh and it may be an old wives tale, but you never know.

big chunks of radiator sealant, so can get bunged up. I've not seen this in the flesh and it may be an old wives tale, but you never know.

Saw this on a Volvo 340 - blocked the radiator solid but it was only leaking after a flush because some helpful person had been using it to top up the oil.... guess it was probably a reaction on that one with the oil.

Man did that car overheat & go bang!!

Is there anything you can put though a system to dissolve radweld?

I would think a Rad flush solution of some description or if I remember right Willie said kettle descaler is good for cleaning out the muck in the waterworks.