Rear Brake Pedal Long Travel Problem?

[ianm00]

I replaced the rear brake pads on my 2014 R1200 GS (TE Model). However the rear brake pedal seems to have a long amount of travel before operating the brakes.

What could cause this issue?
I didn't release any brake fluid just gently eased the pistons back in and slotted in new pads.

Any ideas?

 

[matchbox]

Have you pumped the pedal a few times to bring the pads up to the disc?

 

[ianm00]

Hi yes pumped the pedal lots. The brakes do seem to work just the pedal has to travel a long way down.
I cannot think of any reason why they are like this. I have changed loads brake pads before on my 2006 GS and many cars so Im not sure what the issue is here?

 

[Deleted account 190920001]

Assuming it isn't simply needing bleed.
Only seen it a couple of times but maybe the pistons have been pushed back too far. Remove calliper/pads and pump the pistons out a bit and push it back together so it's slightly tight/rubbing. If you look you can probably see the pistons moving with the peddle it's just they are a little too far in and return too far. They usually reset after a few hundred miles but doing it manually sorts it right away. Like I said I have only seen it a few times and I have no idea why it can sometimes happen but it can.

 

[ianm00]

Assuming it isn't simply needing bleed.
Only seen it a couple of times but maybe the pistons have been pushed back too far. Remove calliper/pads and pump the pistons out a bit and push it back together so it's slightly tight/rubbing. If you look you can probably see the pistons moving with the peddle it's just they are a little too far in and return too far. They usually reset after a few hundred miles but doing it manually sorts it right away. Like I said I have only seen it a few times and I have no idea why it can sometimes happen but it can.

OK will give this a try at the weekend as away for few days now. Would they need bleeding after just changing pads? (never had to a bleed brakes when changing pads before). No fluid came out or was let out when changing the pads.

Thanks for the advice

 

[Engineer]

I replaced the rear brake pads on my 2014 R1200 GS (TE Model). However the rear brake pedal seems to have a long amount of travel before operating the brakes.

What could cause this issue?
I didn't release any brake fluid just gently eased the pistons back in and slotted in new pads.

Any ideas?

My LC rear brake is always short travel and 'solid' feeling immediately after a service but it goes soft and long travel again within a matter of weeks, I think the fluid must be absorbing water through a less than perfect seal somewhere.

 

[ChazzyB]

My pedal has too much travel from new. New pads and fluid change, not at same time, haven't changed anything.

 

[tadhgocuilleain]

Were the old pads very badly worn? Apparently, that can cause the fluid level to drop below the minimum and cause the system to take in air. I've never seen it myself, though.

Check the calliper to make sure it's not weeping fluid. It's possible that dirt on the piston scored the seal when you were pushing them back. I hope not. I hope you just have to pump the pistons out as Marki_GSA said.

 

[roamer]

The pads may not have seated on the steel shims in the calliper, or the disc may be worn and the pads are sitting on the high spots making it feel springy,,

 

[ianm00]

Hi

I removed the pads and pumped pistons out a bit more and re-fitted but its still the same. I think too much pedal travel. The pistons dont seem to retract fully and when turning wheel by hand they are just lightly rubbing the disks (not binding in any way) which I think is normal.

Pistons were relatively clean, old pads were not fully worn out either.
I cannot see any fluid leaks. Bike is still in warranty for few more weeks so will take it to BMW to check as something isn't right.

The brakes do work but I think pedal travel is too far.

Thanks for all the suggestions.

Ian

 

[matchbox]

There is an adjuster below the slave cylinder which will alter pedal height/travel.

 

[Nikonnigel]

There is an adjuster below the slave cylinder which will alter pedal height/travel.

DO NOT adjust that nut you will end up with the rear brake locking on.

 

[ianm00]

There is an adjuster below the slave cylinder which will alter pedal height/travel.

This is not an adjuster. It just sets a small amount of free play, there is NO adjuster for adjusting pedal travel!

 

[ManicMic]

I got in touch with my local dealer regarding my excessive rear brake travel and they bled the brakes and all is good again.

They told me that GSA's (LC's) have a tendancy to let in air into the braking system. Apparently it's quite common.

 

[Shamone]

I got in touch with my local dealer regarding my excessive rear brake travel and they bled the brakes and all is good again.

They told me that GSA's (LC's) have a tendancy to let in air into the braking system. Apparently it's quite common.

Good feedback as mine ended up with too much travel, no leaks, pads barely worn and bleeding did help. Still think I have a little air still in the circuit so may do another bleed.


Sent from my iPhone using Tapatalk

 

[ianm00]

Hi,

What I cant understand is how air can get into the sealed system?

Ian

 

[ManicMic]

Neither can I but that's what the dealer told me.

I looked for leaks and so did they so it's still a bit of a mystery to me as well.

 

[ianm00]

Took the bike to dealer today for checking. They tried to bleed the brakes but broke the bleed nipple off in the calliper!
Now they have to order new calliper and replace it!

Further updates to follow when the calliper is replaced.

Ian

 

[DaveTez]

Same problem different thread!

I replied to another thread on the same subject yesterday:

My 2013 GS also developed the same problem, but I sold it before the issue was fixed!
However, my new 2016 2600 miler is not as good as I would like so I had a BM technician take a quick look.

He told me that its not a bleeding issue (you probably wont get any air out) but down to the fit of the rubber piston seals in their bores i.e. Very tight. (Cant quite remember the exact wording or figure out the logic!) sure someone will!

He went on to show me that by physically pushing the calliper against the disk & thus forcing the piston fully back into its bore that the brake pedal would have loads of movement. By activating the brake a few times the pedal was back to the top of its travel & firm again (try it!).
Another of his customers had admitted to not using the rear brake as much due to the brakes being linked, this had also resulted with the same problem.
I'll start using mine a bit more & see how it feels!

 

[ianm00]

Update:

The dealer replaced the calliper today. I collected the bike and the brake pedal travel is now much less than before.

Ian