I have a little Brake Line query.

[Abott10]

During the past few months I have fitted ZT190 325mm Brake Discs and the ZT190 "BMW" calipers to both my MG ZT-T 1.8Ts I plan to keep. That along with Mintex and Brembo Brake Pads shows definite improvement to the cars' braking with a "feel" and feedback I prefer.

During fitting those upgrades, I noticed the few CMs of "exposed" metal Brake Line inside the front Wheel Arches have some level of surface corrosion. Exposure to the filth from the Road wheels has corroded the short length of pipe there and the Union Nuts which secure the line to the flexible Rubber connection to the Calipers. The same brake line continued on the inside of the engine compartment has no signs of corrosion and looks like new.

Whilst my cars may not be cosmetically spotless, more important things like Braking Systems, Tyres and Suspension etc I like to keep in good shape.

My concern was heightened on the very last Caliper I fitted. Needing to disturb the Union Connection in the wheel arch, the short length of lightly corroded metal brake line there had a "weakness" feel to it. Even so, it may well outlast the life of the cars which so far have now become my daily drivers although one is now on SORN.

Because of this surface "corrosion" observation I am considering renewing the whole affected Brake Lines along with new Union Nuts. I have a flaring kit ... the Flares used appear to be the "Bubble" type in those I have observed. My kit can do those. I plan to use 3/16" Cupro-Nikel Brake Lines. Giving it more thought, rather than replace the whole metal Brake Lines, I believe it is possible to insert a new section connected to the still near perfect majority of the rest of the line using a double ended Coupling.That may entail far less work than renewing the whole Brake Line which looks like needing to remove lots of stuff in the way to gain fitting access.

So, a question. What would be the best course of action. Leave as is? Renew only the Corroded section using a coupling or finally, renew the whole length with new Union Nuts and Cupro-Nikel Brake Line Tubing?

Cupro-Nickel is highly resistant to corrosion apparently.

Any advice or pointers particularly from those who've "been there, done that" will be greatly appreciated.

[clf]

I havent been there done that ......... yet,

Personally, if it was me, I would replace if I had the tools and ability (and if I didnt, I would pass it to someone who did lol). If you add a union, I would be concerned of introducing a potential weak spot (leakage?).

[rustymotor]

I had a similar thought regarding front to back brake lines, I got hold of the unions, cut both original pipe to join a piece of Kunifer however, I couldn't get a decent flare on the original steel brake line and both leaked.In the end replaced both with complete runs.

Same on one side front, as these are quite short replaced the whole piece. This is not to say it can't be done, you may well have a very good flaring tool in which case a joint should be no problem. This is the tool I use. Ebay

[Mike Noc]

If you want to flare the steel pipes on the car then you'll need something like this:

https://www.ebay.co.uk/itm/Sykes-Pic...72.m2749.l2649

As recommended by Marinabrian, and it does look a decent bit of kit.

Bought one a couple of weeks back, just waiting for the warmer weather to start using it.







.

[roverbarmy]

I noticed similar corrosion starting on my brake pipes, before my MOT. I gave them a good wire brushing and the corrosion was just on the surface ( it looked worse than it was) so I gave them plenty of coats red oxide, followed by gloss black, then a smear of waterproof grease. I didn't want to disturb the brake lines, with all the hassle that goes with that. I check them regularly and now have a pressure washer to keep the salt off those "sensitive" areas!

[COLVERT]

Do you have a micrometer ??

Clean the affected area and check the pipe diameter with a good section.

The pipe walls are quite thick and any serious wear will be immediately obvious.


Working on the principle that if it ain't broke don't try to fix it.---

[marinabrian]

I have one of those as well as the Flaremaster that Mike linked to, and I can confirm it won't be suitable to flare the steel pipe.

While perfectly adequate for use with Kunifer or copper, it's impossible in practice to provide enough clamping load on steel pipe to allow it to be successfully flared

In answer to your original question, yes I have replaced sections of brake pipe where only the exposed section has deteriorated

Brian

[marinabrian]

When you make up the replacement pipe, leave the final bend where the pipe passes through the grommet in the inner wing until the pipe is fitted, otherwise you will need to disconnect the A/C pipework

Other than that, the 1800 is the model easiest to do the job on the car

Brian