oversize brake pads?

[Emile]

The only thing I can think is that the new rear pads I just fitted to my R1200 Gs '04 are too thick, while prepared to admit the thickness may only be in my head, can anyone see a cause/soloution to my problem?

I ordered a new set of rear pads from Norman's, put them in as per described in the manual (last time I needed a new set BMW did them along with the service) but after fitting the rear wheel is now very stiff and will only reluctantly turn by hand, if ridden, the bike will not free wheel in neuteral for far at all and the disc reaches a very high tempreature. In other words the brake pads are in constant contact with the disc and becoming operational with the brake pedal off.
When removing to inspect the set up, I can push the pistons in by my fingers, insert the pads, pin, R clip etc and mount the caliper, it is only when I tighten the caliper bolts the last few turns that the pads seem to take effect and stop the wheel from rotating without problems.
I must stress that both pistons retract fully, and their is enough room for the wheel to move until those bolts are tightened.


thanks to anyone who may be able to help me..............

 

[Bones]

I have just changed my rear pads and they didn't drag at all until the brake lever was applied with the ignition on. I fitted Ferodo sintered pads which do look thick compared to wafers I'd removed. They did drag a bit causing the disk to get fairly hot but this stopped happening after a few miles.

Cant think why the pads would drag when the caliper bolts are tightened especially if the brake lever hadn't been applied yet.

I followed these instructions, there is a pic of a new pad I seem to remember for you to compare thickness

http://www.r1200gs.info/howto/brakepads.html

 

[JohnC]

Hoping I'm not teaching you to suck eggs, but do you know that the pad on the piston side is thicker? Or, you could have a warped disc.

 

[Shep]

Or perhaps the master cylinder is full??

And if its an ABS bike, the brake circuit is not simple, i think there are 3 mastercylinders to cover the circuit

Shep

 

[SteveBC]

Just an off chance, but an easy mistake to make, look carefully to make sure that you have not trapped the ABS sensor wire or something else like the end of a cable tie between the caliper and the mounting bracket. This will cause the caliper to 'tip' slightly when you tighten the mounting bolts and then creat the drag you are experiencing.

SteveBC.

 

[Bydand]

Yip, i've had exactly this problem when I fitted a new set of EBC pads to the rear of my GS. Ultimate result was that I had to remove the inner pad as it was too thick. It looks like it is too thick full stop but I'm running the old inner pad with the new outer pad for a couple of thousand miles and then I'll re-try the new inner one. This is my third set in 24k and whilst this rate of attrition doesnt reflect my experince with prevoius bikes I guess its the linked brakes, it is the first time I've used anything other that the bmw parts.

Who-ever suggested that the pads had been put in the wrong side obviously hasn't changed a set.....they only fit one way on my GS!

 

[JohnC]

Yip, i've had exactly this problem when I fitted a new set of EBC pads to the rear of my GS. Ultimate result was that I had to remove the inner pad as it was too thick. It looks like it is too thick full stop but I'm running the old inner pad with the new outer pad for a couple of thousand miles and then I'll re-try the new inner one. This is my third set in 24k and whilst this rate of attrition doesnt reflect my experince with prevoius bikes I guess its the linked brakes, it is the first time I've used anything other that the bmw parts.

Who-ever suggested that the pads had been put in the wrong side obviously hasn't changed a set.....they only fit one way on my GS!

Correct, my bad, of course they can only fit in one way on the 12, I've certainly changed enough Must have been thinking of something else, perhaps my old 11.

Perhaps I'm just gettin sea lion

 

[VAL. H.]

The only thing I can think is that the new rear pads I just fitted to my R1200 Gs '04 are too thick, while prepared to admit the thickness may only be in my head, can anyone see a cause/soloution to my problem?

I ordered a new set of rear pads from Norman's, put them in as per described in the manual (last time I needed a new set BMW did them along with the service) but after fitting the rear wheel is now very stiff and will only reluctantly turn by hand, if ridden, the bike will not free wheel in neuteral for far at all and the disc reaches a very high tempreature. In other words the brake pads are in constant contact with the disc and becoming operational with the brake pedal off.
When removing to inspect the set up, I can push the pistons in by my fingers, insert the pads, pin, R clip etc and mount the caliper, it is only when I tighten the caliper bolts the last few turns that the pads seem to take effect and stop the wheel from rotating without problems.
I must stress that both pistons retract fully, and their is enough room for the wheel to move until those bolts are tightened.


thanks to anyone who may be able to help me..............

I have EBC pads fitted in my 1200. No issues, no problems.

Have you checked for any thing that could be trapped?

Have you ever topped up your breakfluid resivouir? This would prevent the pistons retracting fully.

Have you by chance fitted a new disk?

Fu+k I don't know Take the effin thing apart and do it again

 

[Wizard]

Given BMWs propensity to use materials made of 50% rust & 50% paint, it could be that your piston is a wee bit corroded and not seating fully back in the caliper. Pump it out a bit (stick your old pads in the caliper first) and check it.

 

[Jon P]

Correct, my bad, of course they can only fit in one way on the 12, I've certainly changed enough Must have been thinking of something else, perhaps my old 11.

Perhaps I'm just gettin sea lion

All four valvers only fit one way........

 

[Bydand]

Guys, when I came across the problem I did check for pretty much everything you've noted, everything was OK. The wheel would rotate happily with the caliper and new pads in place, it was only when I tightened the caliper that the problem became apparent. I think that no matter the wear on the outer pad, the inner will always be a wee bit too thick, I'll re-post with an update in a few weeks when I get some more miles on. BMW.....

 

[Deleted account 211025001]

Clutching at straws a bit, but as has already been suggested, could be a warped disk - not unheard of on 1200's.

Also, I can't remember if the rear is a slidding caliper, if it is did you take it apart, clean and re-grease the pin? Ditto the pin the pads slide on?

Will be interested to hear what you find in the end, am on my second set of EBCs with no problems.

Andres

 

[The Bede]

... To my feeeble logic, if the wheel and disc rotates properly when the caliper is 'loose' it doesn't sound like the new pads are over-thick

... Could this be the caliper bolts are being over-tightened (they're only spec'd to 24NM, which aint a lot), or is there an obstruction which is throwing the caliper off square?

... I have the allegedly 'thick' ferodos and haven't had this problem. I re-torqued all my caliper bolts after the pads were changed at the last service.

 

[SilverFish]

... Could this be the caliper bolts are being over-tightened (they're only spec'd to 24NM, which aint a lot), or is there an obstruction which is throwing the caliper off square?

I think I made the same mistake a few years ago on my 1150. Overtightened the caliper bolts, the wheel wouldnt rotate freely. Slackened them off slightly and then found out I had stripped the thread on one

A replacment caliper from Motorworks sorted it all out so could be the torque...

PS Ive since bought a torque wrench and suprised myself at just how little force is needed to tighten things to their proper limits.

Mike