[juffer]

Hi everyone. I have just done the caliper conversion from r53 to r56. Im getting a really long pedel and can't seem to improve it. The calipers were second hand from a working car and looked in good condition. Fitted with grooved discs and mintex pads. The fluid i used was Motul RB660.

I have bled the brakes 3 times with a one way bleeder and a bottle filled with fluid. I bled them from back of the car first to the front. I have since taken it to the garage which they bled them under pressure but it hasn't made any difference.

Do i need a bigger master cylinder? Im now at a loss.

 

[E-R53]

No you don't, many have done exactly this on the standard master.

There must still be air in there somewhere.

Try going for a drive & where safe brake VERY hard to activate the ABS a few times & then bleed again.

I generally find the best way is to use a "Gunsons eazibleed" & also pump the pedal at the same time.

 

[Maccmike]

Definitely air in there still. Follow above ^

 

[HenR56]

I had similar after a caliper change. I tried activating the ABS as above and then bleeding but couldn't get that to work. Used a scan tool with ABS bleed function and that sorted it out.

 

[juffer]

Thank you for all your suggestions. I Went out today for a drive and triggered the ABS about 8-10 times over a 20 mile distance. I came back home and bled the brakes again. Still no luck! I also tried it again with the ignition on so the module was ticking thinking this may be doing something but that didn't work either.

The pedal is solid if the engine is off, it just goes long when engine is on.

Would the torque app be able to trigger the ABS bleed function?

 

[Micke]

Had a similar situation after installing the R56 front brakes. Had to bleed it several times before the feel was as expected.

 

[CarsOrBikes]

fwiw R56 kit does give a longer pedal than 53 stock kit

 

[juffer]

If I can't get it to bleed with the ABS bleed mode and it is just the normal travel, is there anyway of geting a better travel pedel?

 

[CarsOrBikes]

well we don't know if what you have is 'normal' for this mod in fairness, just advising travel is a bit longer if doing it, I'd avoid dicking about with master cylinders, the stock one works for brakes much bigger than these, some people who've changed them have since reverted to stock realising they messed the system up somewhat, one thing you could try if inclined is pumping the pedal up and holding it down as in old school bleeding then vent the master cylinder connections a bit

 

[NigelStap]

The pedal on my R53 has a longer travel with the R56 front brakes fitted. It isn't spongy.

Later edit: When I say longer, I do mean only slightly. Certainly not soft.

 

[Mysticarl]

I noticed a slightly longer pedal on my R56 conversion but it was a small difference. Even on the BBK now it's not really noticeable, though they took 2-3 attempts to bleed properly.

In case anyone is tempted by these, I changed my caliper bleed nipples to one-way ones to 'help' with bleeding, and they're all off again now. One failed and barely allowed anything through it, the others still got air in from the threaded side unless you were very careful. I've since got a decent ez bleeder (£80 or so from demontweeks) and I've not had any issues since then.

Some tools can activate the ABS - my foxwell tool can but I've not used it. BMW dealers can of course but I expect they charge an arm and a leg. The ABS activation is best on gravel I believe as it gives the system more agitation compared to tarmac. Make sure to re-bleed after the activations as any air should then hopefully be out of the module and in the brake lines. Tapping the calipers gently with a rubber mallet when bleeding can help as well.

 

[juffer]

Thank you all so much for your help & input

 

[R53-Luke]

A nice reminder of how I don't miss fucking about with cars

 

[lordf]

It shouldn't be that much difference in pedal travel, my car wasn't with the R56 standard or JCW 4 pot calipers. You can bleed the ABS module with a most of the decent plugin code readers now, they should list the function.

 

[HenR56]

Where you based OP? Might be worth seeing if anyone local has a obd plugin you can borrow that activates the ABS. At least you'll know then that it's done properly.