How easy it to replace a section of corroded brake pipe?

my3cents

Just had a pre NCT inspection and noticed a short section of rear brake pipe that has surface rust on it. The mechanic said not to worry good chance it will pass but I might do it myself as I intend to treat that area with Waxol undersealer so will have it jacked up for that. One corner of the car where its parked catches the wind and salt from the sea hence the rust and me wanting to treat it or at least try and stop it getting worse.

I've looked online and in principle replacing part of the break pipe looks easy enough but I still have some questions.

Pipe diameter? - VW Polo
Pipe type steel/copper? Can you mix steel original with copper as a replacement?
Where to source?

biko

I suppose you can take it on as a pet project but try just sanding the area and see if that removes all surface rust.

Have you done pipes before? It can be tricky and you'll need a special flaring tool.

CJhaughey

Not easy joining steel to Cunifer, the steel is usually a lot harder to flare.

colm_mcm

A garage wouldn't charge ,uch to do a job like this and will have the equipment and knowhow to do it right.

CJhaughey

I'd agree but it depends on what car and where the corrosion is as to the cost.
My old Avensis needed the tank dropped to replace brake lines and it wasn't that cheap.
I'd just sand them back and paint them with a decent zinc rich paint black or olive green to cover the surface rust and protect from more corrosion.

cletus

I failed recently on what was supposedly advanced corrosion. When I cleaned off the muck and sh1te, it turned out to be surface rust.

Clean back to bare metal, prime and paint.

I did this and passed the retest

my3cents

Thanks for all the replies, access isn't too bad and the pipe in question is easy to get at but after an initial burst of enthusiasm I might just clean it up then paint it. Then waxol the whole area.

biko

Sound, just make double sure you get all rust off and that it was just surface rust.

porsche boy

If you are going to do this job make sure the connectors are tight and have someone press hard on the brake pedal with the engine running to check for leaks at all connection points. Another tip is if you are flaring the origional metal pipe turn that into the male connector as if its falred to female it will crack.

martyc5674

If you can completely remove the corroded brake line end to end your cheapest solution is eBay.
There's a few lads there that will cut cunifer pipe to whatever length you want... Flare it and include the fittings.
All you'll have to do is swap it out with existing and shape it into place.... Bleed etc etc.
I've done this a few times and it worked a treat... I've since bought my own flare tool which is great too.
Take care disconnecting pipes that you don't damage the pipe you are connected to.. Often the compression fitting completely seizes to a pipe and when you start twisting it the whole pipe twists...
Marty.

my3cents

The one that needs replacing is the longest one on the car with the most bends so replacing a section sounded a better idea than the whole run. Replacing the whole pipe was my first thought.

visual

my3cents wrote: »

The one that needs replacing is the longest one on the car with the most bends so replacing a section sounded a better idea than the whole run. Replacing the whole pipe was my first thought.

your first thought was the correct thought

mikiejon

i have replaced pipes before, and if i could have gotten away with cleaning it i would have. i would say clean it and see how bad it is.

martyc5674

my3cents wrote: »

The one that needs replacing is the longest one on the car with the most bends so replacing a section sounded a better idea than the whole run. Replacing the whole pipe was my first thought.

You will definitely need a flare tool then to put flares on pipe ends you leave behind. You'll also need to chop your pipes leaving enough room to operate the tool, definitely try clean up the pipes first!!!
Marty.