Any tips / advice please.
 

Hi all

Whilst in the process of rebuilding my rear suspension I have decided to replace the rear flex brake hoses. The one's on the car look like the original one's. As usual, the hard line flare nut has corroded to the hard line steel pipe. So it will not turn. I have managed to crack it loose enough to remove it if only I could rotate the flex pipe.

You guessed it, the flex pipe has corroded into the aluminium bracket that secures it and will not turn. So, catch 22.

Any advice on how to deal with this without ripping the aluminium bracket off the car would be much appreciated. I don't want to use any heat on a system that still has brake fluid in it. If the car goes up then the house will go with it. The bracket has been soaking in PB Blast for the last couple of hours but it's still well stuck.

Cheers Frank.

I had this on mine too.

Press the brake pedal and hold it in place (broom against the seat back) and it'll stop the fluid dripping. Cut the hose at the crimp - that's sacrificial now anyway.

Find a long socket which will go over the hose crimp and support the underneath of the bracket, and use a jack or axle stand etc to brace that against the ground. You can then use a cold chisel or chunky screwdriver on the nut to hammer the union out of the bracket without breaking the bracket off the car.

http://forum.a8parts.co.uk/attachmen...1&d=1582723809

Once it's free of the bracket you can spin the hose end off the hardline. I use a small catering-size blowtorch to heat the hardline union until the plastic coating underneath it melts. You can then spin the union on the pipe and move it up from the end, exposing the corrosion which was freezing it in place. I then clean the corrosion off the hardline and paint it with black enamel before sliding the union back in place.

Its worth grabbing some Evapo-rust from Amazon etc. Pour a little in to a bottle cap / aerosol can lid etc, and once the flexi hose is off, you can sit the hardline end in it overnight and it'll dissolve all the rust off the union without damaging the hardline. You can then paint it at the same time as doing the hardline (or after it's reassembled) so you can re-use all the original hardline hardware without having to re-flare the factory lines, which is not a pleasant job.

Brake fluid is flammable yes, but it won't burn inside the hardline as there's no oxygen. I frequently set the drips on fire, but they burn very gently in limited quantities (like alcohol) so can easily be blown out. If you are concerned, with the brake pedal pressed you can let the remaining fluid drip out of the hardline as far as the first bend, then give it a spray with IPA or contact cleaner to rinse out any residue. Once that's dry there should be nothing to burn.

:)

Thanks for that MJ, once again, your an absolute star.

Cheers Frank

Sorry to be a pain MJ

Could you give me your opinion on this please.

I managed to get the fitting free from its bracket with a slight variation of what you suggested (thanks very much).

On the image below you will see what I noticed on the hard line once I could see it more clearly.

My gut feeling is telling me "bubbling = corrosion" underneath. Can this usually be cleaned up and Re-painted or am I gonna have to splice in a new section.

I realise this is a difficult question without you actually being able to see under the bubble, just wondering if your experience may say it usually goes one way or the other.

Cheers Frank

Clean it and paint it +++

The pipes are galvanised and so the corrosion is zinc oxide bubbling up under the plastic coating. I've never seen one rust as the galvanising completely permeates the steel on something this size. They can get a bit pitted, but I've yet to see one bad enough to need replacing. I use scotchbrite wheels in the dremel to clean the pipe up, degrease, then a couple of coats of black enamel. You'll find the corrosion probably goes a few cm past the visible bubbles. Scotchbrite (or a fine wire brush & 400-grit paper) will take the plastic coating off anywhere there is corrosion, but where the pipe is still sound the plastic will still be stuck to it.

Again, thanks for that MJ.