Replacing brake lines

[dm9two]

Hi All,

Long time listener, first time caller

My 1998 Discovery 1 (3.9 V8i) recently failed an MOT due to corrosion on the brake lines (sections from the ABS unit to rear wheels), I've had a bit of a look online and can find some general information on replacing brake lines but not too much specific to Discos...

Has anyone done this? How hard is it to do myself? I would say I'm generally able to use tools and know the right end of a spanner, previously replaced things like pads, rotors, oil, filters, etc. but haven't really ventured any further upstream in the braking system.

If not what kinda price would you expect from a garage to do this, got a quote of £400 from the MOT place but would be interested to hear what others have paid for this in the past. I'm selling the car too so would like to avoid spending lots on it if possible but obviously want it to be safe and in decent condition.

I read that they come with steel brake lines but when replacing it makes sense to go with copper for anti corrosion reasons and ease of fitting, is this sensible?

TL;DR - Advice on replacing corroded brake lines please.

Many thanks,

Dan

[Boydie]

Okay, you need tools wise you need:-

1.) A couple of brake line spanners, from memory 3/8"--1/4" and 5/16"--1/2" (these are like a ring spanner but with a cut-out for the tube to slot through)

2.) A double flaring tool set.

3.) A 5/16" hand pipe bender

4.) A small bore 1/4"-1/2" tube cutter.

Materials,

A.) 2 off 12 foot lengths of steel brake line ( i think your size is 5/16") but measure the diameter with a vernier caliper to make sure

B.) around 6-8 new brake line unions, use your old ones to get the correct threads and bore.

C.) Get a length of fencing wire, at least 10 feet in length.

Note:- If your car's brake pipe isn't 5/16" make sure you get the right pipe bender to suit.

Go to your local brake shop and ask them to show you how to do a double flare, this is essential before you start this job. Use steel pipe, it might corrode over the years but copper age hardens and can crack, here in Australia it's illegal for road use, I'm surprised its allowed in the UK.

Use the fencing wire to make a template from the ABS to the rear "T" and any other brake lines you have to replace. Bend the brake pipe to suit leaving a good 6" of straight pipe at each end. Slide on the brake pipe fitting (make sure its facing the right way, thread to the open end of the pipe) cut the pipe to the correct length with the tube cutter, swage out the burr at the pipes end and do the double flare(s).

Fit the pipe, do the same for the other pipes to be replaced.

The worst part of this job, with an ABS will be bleeding air out of the system, my guess is you will be able to get some tips on how best to do that once you've installed your new pipes, by the way, fit new hoses as well, if the steel pipes are corroded the rubber hoses will be close to their use by date as well. .

[Les Henson]

If the brake pipe is only corroded at the end (near the rear wheel for instance), the exisiting line can be cut where it's clean and a replacement length can be added. Buy a pack of cupro nickel brake pipe (about 20ft in a pack). Male and female connectors are about 15p each and you will need 3, Thread is 10mm fine. No need for a pipe bender as the new pipe can easily be bent by hand but be careful not to kink it. You will need a flaring tool, and a cheapy one will do the job as long as you are careful. There'll be plenty of pipe in the pack so practice a few times before tackling the job and remember to put the fitting on the pipe before you flare it or you'll have to cut the pipe and start again. Female fittings have a flared pipe end (like a trumpet), and male fittings have a mushroom pipe end so that there's a seal when the two are pressed together by the fittings.

Les

[Bowie69]

Oh, and the brake lines are 3/16"!

As above with Les, you can easily just splice in repair sections, even the cheapie tools will still do steel lines if that is what you have on the truck.

You should be able to buy the lines made up though, if you have no interest in making them up in the future. fitting is then unbolt, fit, and bleed, very quick.

Check which lines are corroded, as I think they are in 3 pieces on the Disco, ABS to under passenger/driver front floor, front floor to rear wheel arch, and then under the truck to where the lines go into a rubber flexi down to the rear axle.

However, if ANY of this sounds too much for you, get them to do the work, they will know what needs doing, and depending on where you are, £400 may even be a good rate...

Put a location in your profile

[Sheffield]

In my opinion if you are going to buy 20ft of pipe you may as well replace it all, fron to back rather than try and join it. If you can work carefully it is not a difficult or heavy job. The worst part is getting all the air out afterwards, which may require a certain amount of persistance. I think some thing like an Easy Bleed kit to allow one man bleeding is also a worthwhile investment.

[Les Henson]

A whole pack is less than £20 and replacing the whole length is quite often unnecessary as you then run the risk of extensive fluid loss (and subsequent difficult system bleeding), removal of other components to do the job, breaking retaining clips, etc, etc. My flaring tool is hand held so I can do the job under the vehicle. You can make the replacement pipe first, so no fluid loss until you make the cut in the original pipe. People tend to think that an Eezibleed just connects to one of the tyres, but there's a pressure limit (20psi ?), so if you connect it to one of the tyres on the vehicle, then you run the risk of damage (such as a burst fluid reservoir for example).

Les

[Scooby Jim]

I found the Ezeebleed only good for for initially pulling the fluid through, then it was a 2 man job to bleed properly.

I redid most of my brake system on my series 3 going from a single line setup with no servo, to servo assist twin line.
Bought this kit off ebay, cheap and did the job well. Atleast you wont get the same Imperial fittings like I had

[Boydie]

Is copper allowed in the UK for on road vehicles? Here in Australia is wont pass the DOT design rules as it age hardens and is prone to cracking. I have only ever seen it used on race cars.

[Les Henson]

I've used it for about the last 20 odd years.

Les.

[Scooby Jim]

If in doubt you could always use this, but was told that this is harder to form into shape, and can be brittle.

http://www.ebay.co.uk/itm/CUPRO-NICKEL-FUEL-BRAKE-PIPE-HOSE-LINE-25FT-FOOT-3-16-4-76MM-1-ROLL/191411360861?_trksid=p2045573.c100034.m2102&_trkparms=aid%3D555012%26algo%3DPW.MBE%26ao%3D2%26asc%3D20140107092241%26meid%3D02291c96dfad4ef7baa9ae31d2ce2660%26pid%3D100034%26rk%3D2%26rkt%3D4%26mehot%3Dpp%26sd%3D201275717065

[Ally V8]

Many garages here in the UK use pure copper pipes because it is so easy to work with and they are lazy,wanting a quick easy fix. The Kunifer,or copper / nickel pipe as in the link by Scooby Jim is far better,no problems with failure,work hardening etc. It is more difficult to work with than copper,but does a much better job and is far stronger when attacked by sticks/stones etc that get thrown up when doing off road work.

[Sheffield]

I keep a tyre, a spare from a now scrapped caravan, for the Ezibleed system, that I can inflate to around 10psi. A smaller tyre is also much easier to lift on to the engine bay to connect up. The air pipe with the kit was not long enough to reach the vehicle tyre. The kit seems to work alright for me, which is as well as I am usually on my own doing it.

[qwakers]

i find the ezibleed kit works much better if you wrap ptfe tape around all the bleed nipples threads before starting.

[Bowie69]

Tbh, I always a 30ish psi tyre with eezibleed, never bothered it at all.

Would echo the comment about threads on the nipples -only undo them as much as you need to, otherwise air is drawn in and looks like you are still bleeding it!

[Boydie]

Les, I'm amazed that copper brake line pipe is legal on road cars in the UK, it must be given your rigorous MOT annual tests but I would never use it, I'll stay with cadmium plated steel, it may be harder to work with but apart from it being the only legal type here in Oz copper simply wouldn't take the constant gravel rash and wear of our roads, I even have to wrap the front stainless steel braided lines to protect them.