ABS brake lines

[Mick753]

Anyone replaced the front brake lines on an ABS model at all?

Looking at replacing the front brake line which is the Y affair that splits to each caliper under the yoke (wanted it moving anyway so I could use my Harris Yoke stand) and it seems to run under ther air box to the ABS module, it looks to be a straight forward enough job but I am not going to be that blase and just presume that BMW wouldn't have made this difficult!!! :concern:

The only reason I am doing this is because having got some M4 calipers the ends of the OEM brake lines don't fit (I couldn't justify the HPK or the GP4-RX calipers).

I am discussing with HEL performance at the moment the possibility of them just making up the one brake line rather than having to buy the full ?180 6 line kit.

 

[baz]

I had mine made by b&c.Mind you,that was over 3 years ago and I took the bike to them.
It is possible to get the OE line off in one piece,albeit with some difficulty.
It is also possible to get the OE line back on again,if you wanted to refit the std calipers.

 

[Mick753]

In fairness the actual removal and fitting of the line that runs from the modulator to the front calipers doesn't look that difficult, my bike is sat with the tank off at the moment along with all the bodywork so most of the removing of stuff is done, i would actually contemplate cutting the old hard line out as there wouldn't be much chance of ever refitting it.

What i am interested in is knowing whether or not there are any things or tips be aware of when it comes to replacing the lines and having to bleed the ABS system as it looks a bit of a strange setup in comparison to a car one given that both the front and rear brake are separately operated yet connected to the same modulator. Although i am probably over thinking it but it would seem that they are two separate systems fed by their own reservoir but maintained by one pump?

 

[Eddie]

Not sure if it's the same for your model but on later bikes the brakes are linked, in certain modes if you grab a handful of front brake it will apply some rear brake for you.

Partially integral brakes:- Your motorcycle is equipped with partially integral brakes. Both front and rear brakes are applied when you pull the handbrake lever. The footbrake lever acts only on the rear brake.

 

[baz]

It is certainly easiest to cut the old line,it is curved around the top of the radiator.

The front and rear circuits are totally separate-the linking is electronlcally through the pump.

Bleeding is quite straightforward.Some people recommend vacuum bleeding/syringing backwards through the lines,though I have never had a problem bleeding conventionally.I usually leave it overnight with the brake applied and then give it a quick bleed in the morning,mainly for peace of mind!

 

[Eddie]

I bought a Mityvac a couple of years ago as I was changing brake fluid a lot, great bit of kit for getting the bulk of the brake fluid pulled through but always needs a manual bleed afterwards.

baz's method has always worked for me on other bikes, ABS and non-ABS. Cable tie the lever back to the bar overnight and a quick bleed in the morning. Job done.

 

[bananaman]

+1 normal bleeding..

 

[fast_ryan]

ABS Brake Lines

Bleeding is quite straightforward. Some people recommend vacuum bleeding/syringing backwards through the lines,though I have never had a problem bleeding conventionally. I usually leave it overnight with the brake applied and then give it a quick bleed in the morning, mainly for peace of mind!

+1.

 

[Mick753]

Excellent, cheers for the advice guys, I am in contact with Venhill at the moment who also seem to make custom lines or certainly advertise that they can do the line I am needing for around ?100.

As for the bleeding given that I am putting calipers on with new lines I generally tend to reverse bleed to start with to push any air up the system, before then bleeding as normal. I am intending to throw RBF600 in the front, now that I know that they are separate systems I will leave the rear fluid alone as the rear brake (for when I do need it) works perfectly fine as it is.

 

[fast_ryan]

HEL Performance

You may also want to try HEL as they can make bespoke brake lines for you and are reasonably priced.

 

[Mick753]

Re: HEL Performance

You may also want to try HEL as they can make bespoke brake lines for you and are reasonably priced.

Rang HEL this morning as I was in a particularly impatient mood having been away from the bike all weekend and wanted to make a start whilst I had the day off.

The response I got from HEL was actually not what I expect to be honest, I asked them if they could make a custom brake line for the front based on the original brake line but with some straight unions on the end of the caliper lines instead of the standard bend.

I was told particularly bluntly that they were not allowed to make that line for me, they could only sell me the full 6 line kit because it is an ABS system, even when I insisted that I wanted a custom line made they would not have it citing that there would likely be a different pressure between the ABS system and the newly made line!!

Absolutely ridiculous :excitement:


So I rang Venhill who were only too happy to knock the line together based on the brake line that they already sell as a replacement for the front calipers to ABS modulator, I also asked for them to make them in carbon look, put two flat unions on the caliper ends and to make them ends 20mm longer too. And no for no extra cost. (?110).

I was sorely tempted to just speak to Reactive and change the M4's for HPK's and did even flirt with the idea of getting the GP4-RX calipers instead but truth be told the M4's are a bling item as much as anything but as yourself I wanted 2 pad calipers instead of 4 due to the cost of the pads :tennis:

 

[fast_ryan]

HEL Performance

That's a very surprising response from HEL.

 

[Mick753]

Re: HEL Performance

That's a very surprising response from HEL.

Trust me it completely baffled Venhill too!