Radiator leak

Assuming the radiator is brass or copper then in theroy it can be solderd. Do check though as majority are aluminium & plastic these days (or at least on cars I have). When I had Mk2 cortinas etc they has brass and copper rads and I used to find that a split would get fouled up with rusty water from the leak and I could never clean the surfaces adequately to get solder to adhere. If you can ge the two parts fully apart, then acid cleaning followed by liberal flux should get a good soldered joint. Brazing requires a lot of heat and with good conduction in the metals, this normally means getting the whole radiator hot and then taking the joint area to red heat.Not normally something that the amateur wrokshop can cope with. Unless you are on a seriously tight budget, a recon unit might be the best bet.

Bob

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It's worked for me several times in the past. Mind - that was when radiators had copper cores. I opened the hole (which I'd accidentally poked in it with a screwdriver), tinned the insides of the edges, closed it with pliers and sweated 'em together. Was still watertight several years later.

Thank Guy, and Bob.

It was an idea to avoid having to pay £238 for a new one (Nissan Terrano). Not mine, fortunately. I think I'll give soldering a go.

Si

You might be lucky, but probably not. I attempted it on my Austin A40 - I should point out that I'm very experienced at electrical soldering and i plumbed my entire house - and failed dismally; as I heated up one bit the next bit dissolved.

The local radiator engineers recored it for me. I've never paid anything like that amount; Mercedes 230 at £120 was the dearest recore, the Toyota LandCruiser was a lot less. That's your answer.

I know it can be done sometimes, even on alu ones. Not sure if the bloke who does it welds or brazes, but he's bloody handy at it.

You need a small, but concentrated, heat source. Really something like oxy-acetylene - and the skill to avoid burning straight through the copper. However, I've had some success by using a normal blowlamp and damp rags etc to heatsink the areas you don't want to melt.

As Bob has pointed out, if it can be soldered, the surfaces are often very cruddy. IME, Bakers Fluid is the best flux to use to thoroughly clean and tin the surrounding area, before sweating a tinned brass shim patch to cover the crack. Use the Bakers Fluid with a brush to cool the area after heating and applying some solder. Keep reheating, soldering, and brushing, until the area is nicely tinned, using a butane torch. The main thing is not to get the area too hot. A 100 plus watt soldering iron might do the job, but IMO a torch would be the better choice. Mike.

I did some lead soldering at college as part of a plumbing course - that was fun, getting the two pieces of lead to join without actually going right through the lot. I was aiming for Honda-quality welds :) They had fine-jet oxy-acetylene though, whereas I have a soldering iron and/or a gas torch.

We shall see.

Si