Brake pipe diameter?
 

Hello, hope you are all well.

Does anyone know where I can buy the black coated hard brake pipe fitted to the 8s. I have a small sample which is a genuine part from main dealer and it seems to be 5.1mm outside dia.

Give me a little latitude as I was using a manual vernia to measure and my eyes aren't what they used to be but it is definitely not 4.75mm which is more common.

I actually ordered some 4.75mm green plastic coated just to double check the size and it is definitely smaller. You can measure it and even feel it's different with your fingers.

I know there will be other options but want to keep the car as original as possible so black plastic coated would be my preference.

Can anyone point me in the right direction?

Thanks Frank

I've never found a source for the black stuff. I've tried buying it from TPS but they just cut copper pipe off a roll :tuttut:

Instead of replacing them, I remove the black coating where it is failing, clean the corrosion off the pipes, and paint them using something tough like POR15. If the union is stuck on the end of the pipe (because the corrosion has wedged the plastic coating against the inside of the union then I will remove the hose by turning the caliper (allowing the union to stay put) and then heat the union with a micro-blowtorch until the plastic bubbles out. That will allow the union to be loosened so that it can be moved away from the flare, and then just clean and paint again.

The only place this doesn't work is on the ABS unit since you can't turn it round if the union is stuck.

Well that's a bummer. I bought this kit (vas6056) in preparation of being able to make up my own pipes.

Even with careful removal at some point, some pipework will need replacing.

What's a little odd and frustrating is that the instructions for the kit refers to black 5mm pipe and green 4.75mm pipe. The green stuff I can get quite easy. Go figure!

I have to say, on a more general point, this whole NLA issue we keep running into is really starting to give me the hump. For me, it is the one thing that will really turn me off with these cars. I find myself now spending a fortune on parts "just in case". Increadably annoying.

A genuine vas6056? :eek: Thats a serious commitment to brake pipe flaring!

If I absolutely have to replace a line I just use off the shelf 3/16th copper / kunifer with stock M10x1 fittings, and a vice-mounted flare tool. If the line runs free along its length (or in a vulnerable area) I'll cover it with adhesive-lined heatshrink. If it is clipped in place then I'll paint it with POR.

If you are able to source the real black-coated metric pipe then that would be quite interesting. I'd definitely need a better flare tool to handle steel lines though.

I agree we are in an extremely frustrating situation with parts, entirely of Audi's making as they appear determined to kill off the older models. Audi Tradition is simply a marketing exercise to promote the brand and not (as we naively hoped) to actually support their loyal fans. I refuse to accept defeat though and will keep as many D2s going as I can for as long as I can :p

I just use standard copper pipe

Tool was second hand from ebay.de, £350. I'll keep persuing the 5mm (or 5.1mm) pipe for a while, see if I can find any. Initially it's not looking good though, been on it all morning.

What has triggered this little brake pipe project is that I purchased a second hand set of front callipers (Brembo) to get refurbished, as spares. Every single union and bleed screw was corroded into the caliper. Even using heat, all the aluminium threads came out with the union.

As well as that, the rigid brake pipe from caliper inlet to the holding bracket (where the flex pipe joins it) was badly corroded and simply twisted and broke when I tried to remove it.

I didn't go too careful with it as it was a spare on the bench but it has given me fair worning that if I need to do brake work on the car, I need to be prepared for problems. Especially around the wheel arch areas.

It could be as simple as trying to change the brake fluid and a bleed screw strips out the calliper.

I'm not sure if the whole car is 5mm but if I needed to cut a corroded section out of a 5mm pipe, is it OK to splice in a 4.75mm section?

I'm thinking a 10mm male gland on the 5mm pipe. A 10mm male gland on the 4.75mm pipe connected together with a 10mm double female. Would that work?

Its close enough to make no difference. I make the caliper link pipes from motor-factor copper pipe and standard M10x1 unions.

If you're in the wheel arches the pipes and unions can almost always be saved using the technique I mentioned. I say 'almost' - I've not had to replace one that's joined to a flexi hose yet, but there's always a first time!

I'll ask a friend who works at Ingolstadt if he can get original brake pipe. There are lots of little bits of hardware he knows about that are impossible to find in Etka so he might know a secret number for it!

Is the 4.75 or 3/16" in old money not 5mm O/D when coated with the back plastic stuff?

Anyhoo I wouldn't worry about the .25 of a mm and just use Cuni or copper.

If you really wanted coated LINKY

So, I managed to find some but it is stupidly expensive (approx £230 for 10 mtrs). I need to make a note to self, "stop buying car parts when you are drinking".

I've compared the pipe to the original sample I have and it's the same.

Fundimentaly, it looks to me like 4.75mm with either a thicker tube wall, thicker coating or a combination of both.

I've got it now so I'll keep it but I don't actually think it's necessary to go to this expense. There are plenty of cheaper options.

A backwards move for sure, in contrast to Mercedes, who seem to still sell new parts for 30 year old cars...
It will cost them brand loyalty, if they care?