Replacing corroded rear brake pipes

[georgemason]

I'm in the middle of a boot floor replacement and noticed that the metal brake pipes under the floor are quite corroded near where they join the flexible hoses.

Can I buy replacement copper hose from the motor factors and then join this to the existing pipework somewhere convenient along the pipe run, or do I have to remove the whole lot (seems to be one piece all the way to the front - and the union is in a very innaccessible place! :eek:)

I really hope I don't have to replace the lot!!

[kevinrbeech]

You need to replace the lot back to the next union. If you cut the pipe to join it you would have to use a flange tool under the car to put a new fitting on, given that the original pipes are steel, hence the rust, it would be a very difficult task. If you intent to replace it the easy way to undo the unions without tears is to cut the pipe at the union and put a ring spanner, or socket, over it, far better than an open ended or brake pipe spanner. Don't forget though, fluid will flow freely once the pipe is cut.
A tip is to remove the filler cap on the master cylinder and put a bit of polythene across the hole then put the cap back on, this will stop air from getting in and slow the flow of fluid a little.

[Richie_asg1]

A tip is to remove the filler cap on the master cylinder and put a bit of polythene across the hole then put the cap back on, this will stop air from getting in and slow the flow of fluid a little.

4 layers of clingfilm work quite well - thinner than heavy plastic.

You may be able to get pipe as a made up length if you are thinking of buying all the stuff. Then will just require shaping. Will you be doing this more than once?

[georgemason]

You need to replace the lot back to the next union. If you cut the pipe to join it you would have to use a flange tool under the car to put a new fitting on, given that the original pipes are steel, hence the rust, it would be a very difficult task. If you intent to replace it the easy way to undo the unions without tears is to cut the pipe at the union and put a ring spanner, or socket, over it, far better than an open ended or brake pipe spanner. Don't forget though, fluid will flow freely once the pipe is cut.
A tip is to remove the filler cap on the master cylinder and put a bit of polythene across the hole then put the cap back on, this will stop air from getting in and slow the flow of fluid a little.Hi Kevin, yeah I feared as much, looks like another big job then. I'll try and get some pipe tomorrow (if the motor spares place is open) and start the job.

The unions seem to be inside the front wheelarch - is there a trick to getting at them? (other than cutting the pipe and using a ring spanner, I'll definitely use that one!) I'm sure its a stupid question but I'll ask anyway :rolleyes:: are the copper pipes that the motor spares shops sell direct replacements for the steel ones?

Cheers for the tip with the resevoir, I'll give that a go.

[georgemason]

4 layers of clingfilm work quite well - thinner than heavy plastic.I've got some of those latex gloves, they work very well for this type of thing...

You may be able to get pipe as a made up length if you are thinking of buying all the stuff. Then will just require shaping. Will you be doing this more than once?Hopefully this repair will last at least as long as the Disco does so I reckon I'll only do it once (obviously once for each of the two corroded pipes). I guess I'll go to the motor factors and see what they say.

[kevinrbeech]

Pipe flaring tool from Machine Mart will cost about £20, probably less. Copper/Nickel pipe about £15, you can, if you use my method of removal, re-use the unions on the new pipe so no expence there, and you know they are going to fit.
You'll have pipe left over and you've always got the flaring tool.
There should be a union under the transmission tunnel, depends on the car, my 200 has one.
If reply doesn't make sense or cr*p typing, it is due to a bottle of red wine.

[georgemason]

Pipe flaring tool from Machine Mart will cost about £20, probably less. Copper/Nickel pipe about £15, you can, if you use my method of removal, re-use the unions on the new pipe so no expence there, and you know they are going to fit.
You'll have pipe left over and you've always got the flaring tool.
There should be a union under the transmission tunnel, depends on the car, my 200 has one.
If reply doesn't make sense or cr*p typing, it is due to a bottle of red wine.No worries, made perfect sense!

I had another look today and can't find any union other than in the nearside front wheelarch (photo attached, along with one of the state of the pipes at the back). Looks like it will be a nightmare to get to, so I'm wondering whether there are any options other than replacing the whole section from front to back....

[kevinrbeech]

Yeah, that looks like the one, I thought it was further back than that. It will probably come undone easy just make sure you have good spanners on it.

[georgemason]

I notice this tool on Machine Mart, is it worth having one for the job, or am I as well to bend the pipes around a screwdriver handle or similar?
http://www.machinemart.co.uk/shop/product/details/cht264-3-in-1-automotive-pipe-bender/path/automotive-tools