Replacing front brake lines

[junkie 0]

Going to start sorting my car out and i need to replace the front copper brake lines.

 

I will be ok actually making the lines themselves but how do i go about removing the old ones etc, basically is it inevitable i need to make a mess with brake fluid, do i need to top up and bleed the brakes after, if so can i just top up again or is it a full fluid change, which has been done already 2-3 years ok with no more than 10k on them.

 

Also what size pipe doi need?

 

Any tips greatly appreciated.

 

Simon

[G60SC_Stoney 0]

im also going to be doing this job sometime in the near future, so BUMP!

[junkie 0]

Also looking at my brake lines yesterday, what constitutes a corroded to excess brake pipe, as yes there is corrosion but to me they look ok, nothing a very quick scrub down wouldnt sort out, im sure they were changed approk 3-4 years ago so surely they cant have corroded to excess in that time with approk 20k on them.

[aclwalker 3]

Last year I replaced all brake pipes right up to the ABS unit under the bonnet. The only original pipes are now under the bonnet (ABS to master cylinder etc.).

 

I got all the bits from http://www.automec.co.uk. I bought their "Universal Light" flaring tool I think it was, which was around £100 but it's a lovely piece of equipment which makes great beautiful flares on your pipes. It's a lot of money but even if I only used it once it's paid for itself. You can get hand-held flaring tools much cheaper but in my experience, the force needed to make excellent flares is too great for a hand held tool. The Automec flaring tools are used in a vice. Hand held tools allow you to do a pipe in situ though, but I don't think that's really necessary or advisable.

 

I bought the normal copper pipe from them. Some people prefer the copper nickel as opposed to the standard copper as it's harder, but that just makes it much harder to bend, so I opted fro the standard copper.

 

It's advisable to get a bending tool too from the same website, as although you can easily bend copper by hand, there are places you'll want a tight bend. Their basic bending tool isn't very expensive. You may want to also buy the deburring tool to clean up the cut pipe. Oh yes, you'll need a pipe cutter too. I got one from a website that a guy on here started I think. The name escapes me, but any adjustable copper pipe cutter will do. I think B&Q even sell them.

 

My original brake pipes failed the MoT and I'm actually glad the guy did it. I really like the MoT guy who does my car. He really likes the car, squeezes us (me and my dad) in to his schedule when he recognises the car on the phone and doesn't fail it on trivia that you can't prove otherwise.

 

When I saw the pipes I was actually shocked. Also, my brake hoses were bulging at points.

 

If you're going to replace your brake lines and your hoses are old too, then I would just get the full set of 6. I got mine from GSF but others prefer Goodridge braided hoses.

 

Incidentally, you've got virtually no chance of removing the unions from the old pipe anyway, as they will be corroded on.

 

The best way to remove the old pipes is with bolt cutters. Try to catch the fluid with newspaper.

 

Fitting the new pipes around the car is surprisingly easy. Some bits are a bit tough because you have to get it behind heat shields for the exhaust, but be systematic and it's no problem. You may have to use cable ties to secure them to places as the original plastic clips will likely have broken off.

 

It's a good idea to 'seal' the brake reservoir with cling film, then put the lid on as this helps to minimise leakage and prevent the complete emptying of the system. Another tip is to make a sort of plug with one of your new unions and a hammered down small piece of copper pipe (flared at the union, obviously) and place this temporarily in the ABS unit for the particular pipe you are replacing. This again helps to minimise leakage and air ingress.

 

You need to watch with the unions, as most are the standard M10 male unions for German cars, but one of them is an M12. I'm not quite sure why this is but I think it's to ensure that you fit the pipes back in the same order. So you'll need to buy M10 unions and a couple of M12 (if you want to make an M12 temporary plug too) unions from Automec.

 

All in all, I replaced all four brake lines right back to the ABS unit, all new brass unions (lovely quality), bought a brake flaring tool, cutter, bending tool and deburrer, with new copper pipe and new flexible hoses for probably around £150-170. Something like that. Most of the cost is the tools, but you'll always have them.

 

Also, when you make the flares up, take care to make the right one. VWs use what I think they call a single flare, whereas the tool can make single or double. Basically, just read the instruction carefully and compare your flare with those on the original pipes and you can't go wrong. It's very important to remove burrs though before flaring as they WILL leak if you don't do this.

 

Oh, another thing. You will likely want to replace the brake pressure compensation valve which is attached to the rear suspension and reduces braking pressure on the rear as the car tilts forward (to prevent rear wheel lock under heavy braking). Mine was original and was totally gubbed and just about seized. If you're replacing all your pipes then just get a new one of these. They are not that expensive if bought on the Internet. Be careful to note which pipes went where (there are two inlets and two outlets).

 

After bleeding the air out, check very carefully for fluid leaks. New fluid is harder to see because it's clean. I had a very minor leak which was cured by tightening it up. I was worried about over tightening them and deforming the flare.

 

Just remembered, you might want to get a brake pipe spanner. I'd buy one from Halfords for this. The Automec one is very cheap and not really up to it.

 

One more thing, the hardest bit with the fronts is probably getting it through the sidewall of the engine bay. There's a rubber grommet that you need to remember to put on the pipe BEFORE doing the final flare. Likewise you need to remember to put the unions on the pipe BEFORE doing the last flare, otherwise you'll need to cut the pipe again to get them on! Aligning the pipe through to the engine bay, with this grommet such that it doesn't rub and follows the rough path of the old pipe can be tricky.

 

Lasty(!) the size of pipe is 3/16".

[junkie 0]

Good post and 1 i think somebody needs to put in the knowledge base before its lost.

 

Agree with all on the flares etc i have all the tools already been a fridge man :D

[G60SC_Stoney 0]

thanks for the top info! going to get stuck into this after i come back from holiday!

[aclwalker 3]

I took some photos today of the tools I mentioned in my post above.

 

Firstly, here's the box you get with the flaring tool. I've got some unions sitting in the top, with some bleed valves and brake hose clips.Corrado92.pdfP6050075.JPG[/attachment:2evci98t]

 

Here's the toolbox opened with the flaring tool visible. It is placed in a vice and the handle used to crank round the die (one is just visible in the top left) into the pipe which is gripped in place by blocks. It's very easy to use. You can also see my Halfords brake spanner. Very good quality. The Automec one isn't really up to much. Also note the wee plug device we made over on the right. You sacrifice a union and a small piece of copper pipe, make a flare as normal (note its domed appearance. The double flares go back in on themselves but VWs use these single flares.) and then hammer down the end of the pipe to make a seal. You can use this as a plug for the ABS while you make up each pipe and minimise fluid loss and air ingress. You should really also make up one with a 12mm union as one of the unions on the ABS is 12mm.passat climatronic wiring diags.pdfP6050077.JPG[/attachment:2evci98t]

 

Here's a picture of the ABS unit under the bonnet. If I remember correctly, the two rightmost unions (from the point of view of this photo) are for the fronts and the next two along from them are the rears. Do one wheel at a time and you can't go wrong. Note that the 3rd one along is a 12mm union. Not sure why but probably something to do with not mixing the rears. I think the rears crossed over each other, so it's probably to make sure. You can't really mix up the fronts as one of them obviously veers off to the passenger side. This is where I used the improvised plug tool I made with the sacrificed union and small length of pipe.climatronic wiring-Golf from May 01.pdfP6050068.JPG[/attachment:2evci98t]

 

Here's the pipe deburring kit, which I forgot also contains a bending tool. Most bends can be done by hand but you will likely want tight ones in some places and this bending tool certainly helps. I didn't find the deburrer so useful, probably because I used a proper cutter which minimises burrs. Many people use hacksaws, which is actually strongly discouraged because burrs and unstraight cuts can occur which make good flares difficult.2.8l 24v Climatronic system.pdfP6050078.JPG[/attachment:2evci98t]

 

And here's my wee cutter. A lovely wee tool. Those who appreciate good tools will enjoy using this! It's Sykes Pickavant and is adjustable such that it can even be used on plumbing pipes! Well worth it again.P6050079.JPG[/attachment:2evci98t]

[Jim Bowen 1]

this is a great post and should be put somewhere if it hasn't already :)

 

am about to do this job next week

[Jim Bowen 1]

i've just ordered what i need from here

 

http://www.brake-pipe.co.uk/index.html

 

as i noticed the site mentioned in this thread has no online ordering

[Chris Smith 0]

i've just ordered what i need from here

 

http://www.brake-pipe.co.uk/index.html

 

as i noticed the site mentioned in this thread has no online ordering

 

Wow, these guys make the pipes to measure and do all the flaring for you! Nice :D

 

How was your experience with this company Corsameal?

[CorradoVR6-Turbo 0]

here is a tip....once you cut the brake pipes you want to change,get a bar of some sort and use this to keep the brake pedal fully depressed onto the floor.wedge it between the pedal and seat.

 

This will stop any fluid from dripping out untill you are finished.

 

and there are much cheaper brake flaring tools out there.

 

As a mechanic ive got access to the full works,but while your doing a pipe on the car or need to replace only half of it ive used all kinds of flaring tools.

 

http://cgi.ebay.co.uk/10-pce-Metric-Fla ... 240%3A1318

 

this one is similar to what i have,works a treat...plus its light.

[boost monkey 0]

James, don't you need an imperial flaring tool as opposed to metric? The line i've been using is 3/16" albeit with 10mmx1mm male connectors :confused4:

[CorradoVR6-Turbo 0]

yea sorry my bad,i just found a link to show what prices can be....should have looked at the text. :morning:

[_leon_ 0]

this is an excellent post. am i right in thinking that all the lines will need moved/replaced if i have the bay cleared for repainting?

[diggerbucket 0]

here is a tip....once you cut the brake pipes you want to change,get a bar of some sort and use this to keep the brake pedal fully depressed onto the floor.wedge it between the pedal and seat.

 

This will stop any fluid from dripping out untill you are finished.

 

I could be speaking rubbish here, but does that not risk damaging the master cylinder?

[Jim Bowen 1]

i took the cap off the brake fluid reseviour, put cling film over the hole and then put cap back on.

thats stops most of the fluid coming out, but you will always get a little

[CorradoVR6-Turbo 0]

here is a tip....once you cut the brake pipes you want to change,get a bar of some sort and use this to keep the brake pedal fully depressed onto the floor.wedge it between the pedal and seat.

 

This will stop any fluid from dripping out untill you are finished.

 

I could be speaking rubbish here, but does that not risk damaging the master cylinder?

 

 

in what way? ive done it for years...never had a problem.

[aclwalker 3]

here is a tip....once you cut the brake pipes you want to change,get a bar of some sort and use this to keep the brake pedal fully depressed onto the floor.wedge it between the pedal and seat.

 

This will stop any fluid from dripping out untill you are finished.

 

I could be speaking rubbish here, but does that not risk damaging the master cylinder?

 

 

in what way? ive done it for years...never had a problem.[/quote:19v8064d]

I think the argument goes that there is a large part of the piston that never goes into the master cylinder and is open to the elements. In cars the age of ours, this part of the piston can be quite badly corroded and if you force the pedal to the floor when doing brake work (e.g. bleeding) then this rust actually tears the rubber seals, causing fluid to leak out of the master cylinder.

 

You would probably get away with this on a new car but on old cars it is risking master cylinder seal damage.

[boost monkey 0]

I'm confused aclwalker.

 

The piston inside the m/c connects integrally to the sprung pushrod inside the brake servo: I don't think at any point in time is any part of the piston exposed to the elements? :shrug:

 

Also, if the m/c seals tore when the brake was fully depressed for a period of time, wouldn't that make emergency stops really dangerous?

[davidwort 0]

I guess it makes sense that part of the piston is never used in normal braking, when bleeding the brakes with a bleed point open the pedal goes to the floor, far further than it would with a sealed system.

I can't picture all the bits that make up the master cylinder/servo in fact I don't think I've ever seen opne totally in bits, only ever changed a non servo one on a polo.

I'm converted to using ez-bleed pressurised bottles now, so much better than pumping the pedal and shouting instructions :lol:

[boost monkey 0]

DW, you are a wizard if you can get the EZ Bleeds to work! Mine píssed out fluid all over the place, could never get it to seal properly on the reservoir.

[Jim Bowen 1]

i used the EZ bleed and it worked perfect :lol:

[CorradoVR6-Turbo 0]

all i can say is that i bleed up to 5 different makes and models of cars all day long everyday. :cuckoo:

 

The method ive used works everytime while changing lines,you could bugger a master cylinder by pushing the seals past a point they have not been for a very long time,but if that is the case then it was about time to renew the master cylinder anyhow. :lol:

 

its only a tip...use easy bleed if you want,but thats for bleeding,i was refering to stopping fluid from dripping on the back of your neck :lol:

[mort1414 0]

here you go ian all the info we need

[Emkayvr6 0]

excellent thread, have just replaced all the front and rear brake lines on mine, as well as m/c, and pressure reg and a few other thing's. Only thing i'd add is that makes sure the union is at the end next to the flares before u bend the pipe otherwise u wont get them round the bends, oh and ABS M/C are expensive, coming in at 240 from the dealers (who only have 2 left in the country now as they ony had 3 when i ordered mine :shock:) and about the same form elsewhere, most part factors only supply non abs ones, although i was supplied with ABS ones that turned out to be non abs, useless feckers!!!