# renewing brake pipes.



## brian1978 (Jul 10, 2013)

I'm renewing my brake pipes, front to back at the weekend, I've done this before on previous cars with little problems.

I know with Audi things are seldom straightforward, when I do this is their anything I need to know?

Is it dot4 for the fluid and when I bleed the system and can I just bleed from the nipples furthest to closest to the master cylinder, or will I need to buy a bleed kit?


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## Hoggy (May 8, 2002)

Hi Brian, Dot 4 super fluid is O.K. & bleed starting at nipple closest to Master cylinder first.
Best to use a pressure bleeder @ Max 15psi & don't let reservoir get low so that air gets into ABS, otherwise VagCom required to remove air.
Hoggy.


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## brian1978 (Jul 10, 2013)

Hoggy said:


> Hi Brian, Dot 4 super fluid is O.K. & bleed starting at nipple closest to Master cylinder first.
> Best to use a pressure bleeder @ Max 15psi & don't let reservoir get low so that air gets into ABS, otherwise VagCom required to remove air.
> Hoggy.


Closest sorry hoggy it's late, thanks didn't know about needing a vag com if air gets in the abs.


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## Fight1 (May 13, 2012)

Before you jump into this have a look at http://www.ko_racer.talktalk.net/tank_remove.pdf 
Because the pipes to the rear run behind the tank. I'm doing the same this weekend as well if the weather holds, but I'm forced to as I broke my lines doing suspension work.
If doing this I would get either new OEM flex hoses for the rear or ss lines if you like the blink, this because the nipples will likely be corroded. Also the rear most part is a hard line with a crimped on flex section.
Good luck, and take som pics :wink: 
F

Edit. On my last brake job I emptied the reservoir, but did not need to use vagcom to cycle the abs pump. The homemade pressure bleeder did just fine on its own. Before starting depress the brake pedal almost all the way down, and lock in place with a piece of wood, this should block the cylinder so it will retain fluid.


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## brian1978 (Jul 10, 2013)

Fight1 said:


> Before you jump into this have a look at http://www.ko_racer.talktalk.net/tank_remove.pdf
> Because the pipes to the rear run behind the tank. I'm doing the same this weekend as well if the weather holds, but I'm forced to as I broke my lines doing suspension work.
> If doing this I would get either new OEM flex hoses for the rear or ss lines if you like the blink, this because the nipples will likely be corroded. Also the rear most part is a hard line with a crimped on flex section.
> Good luck, and take som pics :wink:
> ...


I had a good look over my brakes today, I was doing this as when I look my car in for a coilpack recall Audi did say the lines were fubared, now as the last mot had no advisories I thought I'd give it a good second look, they really ain't that bad, I've had cars pass mots with way worse brake lines so I might just clean them up and put it in for it's test, see what they say.

Bloody stealers, they also told me I need a new spare tyre when it was simply needing air in it. And that I needed a new set of locking nuts as mine wad missing from the thing on the spare tyre, not even asking me if I had it. It was in the glovebox. :roll:


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## mullum (Sep 16, 2011)

I got an advisory today for corroded brake pipes. They told me just to grease them and I'd probably get another 4-5 years out of them.


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## poor1 (Dec 28, 2011)

Don't get caught out renewing your brake pipes when there is no need just for the sake of an MOT which would probably pass them anyway. . It's a pretty big job and expensive in parts. It could result in complications which would be particularly frustrating if everything is working well now.

Might be an idea to change the brake fluid. It should be done every three years or so because the fluid is hydroscopic. Use DOT 4. A Bosch service station would probably change the fluid for about £30.00 so its hardly worth getting you hands dirty. They would probably be able to tell you whether the pipes wanted replacing too.


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## cookbot (Apr 19, 2011)

Changed all mine on axel stands and can confirm it is a horrible job! The near side rear isn't too bad, but the offside goes above the fuel tank. If the part that goes behind the tank is ok, you could splice into it to remove the corroded section? As long as you have a pipe flaring tool, you'll be ok.


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## Fight1 (May 13, 2012)

I'll take the opposing view and say that you are giving bad advice on several levels here. 
1. Parts are not expensive, it's just brake lines and nipples. Abit more if you need the piece from the flex hose to the caliper on the rear on Quattro models. Even the tools required are fairly cheap if you are not dead set on using ss lines. It will cost if you are not DIYing but hey you got a TT so probably rich anyway :wink: 
2. Is this really an area where it is sensible to skimp on money and try too eek out the last year of the brake lines? All modding and upgrading fun should star with tyres, suspension and brakes. Handling and safety first.
3. For 30£ you can build an effektive pressure blender and change your fluid with confidence for the rest of the cars lide. Fluid change is good and cheap safety. And if you do it your self most likely you'll inspect the pads and rotors, and hopefully also the slider pins.

Yes the rear lines are a bitch with the fuel tank and all, but its just time spend, nothing really difficult here. Hope I'm not coming on too strong here, but having left the road rear end first doing 60 I know how expensive hat can be, too say nothing about how scary it is.

Also splicing on is not very easy on the rear pipes given how they twist and turn, not many straight sections long enough after they head up around the tank.

F


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## poor1 (Dec 28, 2011)

Have a look at the failure rate on MOT taken from Honest John's breakdown:

http://good-garage-guide.honestjohn.co. ... di/tt/2002

0.41 fail on hydraulic parts.


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## brian1978 (Jul 10, 2013)

Had a mate in the know look at them. They are not nearly as bad as Audi made out, a few small sections at the back could do with replacing.


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## jamman (May 6, 2002)

brian1978 said:


> Had a mate in the know look at them. They are not nearly as bad as Audi made out, a few small sections at the back could do with replacing.


So lets be fair to your dealer they do need replacing.


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## brian1978 (Jul 10, 2013)

jamman said:


> brian1978 said:
> 
> 
> > Had a mate in the know look at them. They are not nearly as bad as Audi made out, a few small sections at the back could do with replacing.
> ...


3 sections close to the joins at the rear need doing but would prob still pass an mot if I cleaned them up, the dealers told me I needed them done "front to back" ie all of them which simply isn't true, their is very and I mean very slight surface corrosion on some of the pipes more like a discoloration but nothing that will need doing for a few years.

They also told me I needed a new spacesaver tyre, it was just needing some air. :lol:


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## Fight1 (May 13, 2012)

Good luck with doing only sections in the rear. It's steel pipe and flaring that in situ with very little flex in the lines is neither fun nor easy. Believe me I tried. Also it's a fair bet that you'll find the joint/nipple to the flex section rusted, and trying to undo them will twist and rip the line.
And then you'll be back to doing the job correctly anyhow. Devious buggers those Audi engineers 
If you end up with the lowering of the fuel tank scenario do a full bushing refurb in the back and fuel filter at the same time. Everything will be easy to access when you drop the rear subframe .
F


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## poor1 (Dec 28, 2011)

Cupro Nickel is the material used for brake pipes these day, which unlike steel, is highly resistant to corrosion.

Does anyone know for certain what material Audi uses for the TT?.

Here's a company on Ebay who will make up pipes in cupro nickel

http://www.ebay.co.uk/itm/3-16-Brake-Li ... 43bed82912


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## Fight1 (May 13, 2012)

Without being 100% certain I would say the OEM is coated steel. It's hard as f and I was unable to flare it in situ. The coating also makes finding a long enough section without the slightest turn important when planning to replace a section as the joining piece will be tight on. My replacement lines going on are a copper nickel alloy, it won't rust and is easy to work with and I'll paint it black to keep the OEM look.
Also note that the flare used is a bubble flare.
F


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## brian1978 (Jul 10, 2013)

poor1 said:


> Cupro Nickel is the material used for brake pipes these day, which unlike steel, is highly resistant to corrosion.
> 
> Does anyone know for certain what material Audi uses for the TT?.
> 
> ...


I can get all the tools to do this stuff, I done all the lines on my last car and it was a bugger too, but it's just time and patience, coupled with a lot of swearing. I'll prob. end up renewing them all anyway. I tend to start a job and get carried away lol. Last ones I was just going to replace bits and I just kept going. I won't be painting them as nobody will be under the far to look at them, unless I park ontop of them,


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## cookbot (Apr 19, 2011)

Fight1 said:


> Without being 100% certain I would say the OEM is coated steel. It's hard as f and I was unable to flare it in situ. The coating also makes finding a long enough section without the slightest turn important when planning to replace a section as the joining piece will be tight on. My replacement lines going on are a copper nickel alloy, it won't rust and is easy to work with and I'll paint it black to keep the OEM look.
> Also note that the flare used is a bubble flare.
> F


Managed to flare my rear offside, but it wasn't easy like you said. Had to peel back that black protective coating and do it laying upside down, but it is possible.


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## poor1 (Dec 28, 2011)

If the two pipes going to the rear calipers are anything to go by I can confirm these pipes are steel with a plastic coating, so would assume that all the pipe runs are as well. Difficult to understand why Audi went down this route when corrosion was a well recognised problem and cupro nickel had been taken into use on quality vehicle many years before..

As regards the two short pipes to the rear calipers, they incorporate a flexible hose which is swaged into the pipe which would be impossible to replicate and if they want replacing they cost about £35.00 each for a start. The end opposite to the caliper have a standard 10mm fitting. Replacing them alone is more complicated that it looks, let alone replacing any piping running over the top of the tank.


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