17mm o/d copper pipe

[Jamp]

Hi All,

One of the pipes between the bulkhead and heater matrix in my car has a hairline crack on a bend and so is leaking.

At first glance I assumed it was standard 15mm copper pipe but in fact its o/d is 17mm (exactly). It is also a lighter colour than normal copper so perhaps it's brass, but I can't think of why this would be - any suggestions?

Will anyone supply 17mm copper pipe and pre-formed 90deg and 45deg elbows do you think? Failing that, adapter connectors for 17mm - 15mm copper pipe? I would have to adapt it back to 17mm at the end to mate properly to a hose, but could form the bulk of the pipe and the bends out of standard 15mm.

Cheers,

Jamp

 

[TicklyT]

Brass was the traditional material of choice for car radiators and heaters. These days it's more likely to be aluminium and plastic.

I would attempt a repair by silver soldering over the split, or binding it with plain copper wire, and soft soldering it. Where to get the copper wire? - strip all the insulation of an old bit of flex.

If soldering a repair, beware of heat conducted down the pipe melting other joints.

You might be lucky, and find a piece of 15mm copper fits neatly inside your 17mm brass tube for soldering. Maybe use a 15mm solder ring fitting to increase the OD for the hose fitting, as it already has a ridge to help locate it.

In the past I have repaired a split in a heater pipe by sliding a short piece of heater hose over the split, and clamping up the ends with a pair of hose clips. A drop of fairy liquid or swarfega helps lubricate the rubber to get the hose on there in the first place.

A cautionary tale - a friend had his feet badly scalded when a botched heater hose connection blew off the heater matrix, dumping the entire contents of the cooling system, which was at boiling point, into the footwell.

 

[Jamp]

Thanks Tickly. The i/d of the 17mm pipe is only a touch over 15mm so that could be a goer. I might well take your tip of a hose over the join and clamped either side as extra security. This is a dash out job so not something I intend to do twice!

Unfortunately the hose end of the pipe has been squashed previously when trying to remove the (very stubborn) hose. It is now a bit of a mess and whilst it might be possible to persuade it back to round-ish it will probably be a weak point in future. For that reason I'm inclined to replace that end of the pipe (the crack is on the first bend after the squashed hose end), if not the whole lot.

The last issue is going to be making the hoses, intended for 17mm o/d with an 18.5mm diameter 'ridge'. Anyone know of the top of their head what the diameter of the ridge is on standard 15mm solder connectors like this: http://www.toolstation.com/shop/Plumbing/Solder+Ring/d20/sd2699

I wonder if a bigger ridge could be made with a flaring kit like this? http://www.toolstation.com/shop/Hand+Tools/Plumbers+Tools/Flaring+Tool+Kit/d10/sd210/p28625