Rear brake malfunction

[David13]

I had low brakes.  Then after a slightly hard stop, the brake failure light started to come on.  I realized the rear brakes were frozen.  Which makes sense, as I always use only the front by the lever, as they are supposed to be integrated, the front operating the back as well.

I pulled the caliper and they were frozen.  I pushed them in and got them to move a bit but not much.

 

Looking for a rebuild kit, there are none offered anywhere.  BBY says due to a lawsuit they cannot get any more Majura parts.  Max BMW doesn't offer either parts to kits.  They do list the piston seals or o rings but the pistons are number 21 and the sales list only goes to 20. 

 

I haven't even found a place to buy a replacement or rebuilt cylinder.

 

Any ideas.

 

2008 R1200RT with ABS

[dirtrider]

14 minutes ago, David13 said:

I had low brakes.  Then after a slightly hard stop, the brake failure light started to come on.  I realized the rear brakes were frozen.  Which makes sense, as I always use only the front by the lever, as they are supposed to be integrated, the front operating the back as well.

I pulled the caliper and they were frozen.  I pushed them in and got them to move a bit but not much.

 

Looking for a rebuild kit, there are none offered anywhere.  BBY says due to a lawsuit they cannot get any more Majura parts.  Max BMW doesn't offer either parts to kits.  They do list the piston seals or o rings but the pistons are number 21 and the sales list only goes to 20. 

 

I haven't even found a place to buy a replacement or rebuilt cylinder.

 

Any ideas.

 

2008 R1200RT with ABS

 

Evening  David13

 

Maybe look for an E-Bay good used caliper (probably some that are decent).

 

Or try calling Ted Porter 1-831-438-1100, I don't see any listed on his web site but he might know where to find pistons.

[David13]

Thanks dirtrider.

I had looked at the ones on ebay and realized that there is no reason to believe any of them are any better than the ones I have. 

 

I also realized that I need to rebuild the front as well, and that more likely than not it is simply age that caused the seals to fail or harden.  I suppose someone could say I used the brakes too much or wrongly, but I only used them rarely.

 

MaxBMW says they "may" be able to get the pistons for the rear, which don't show on their parts list online.  But that they only sell the front seals with the pistons. 

 

I still haven't taken them apart but I do suppose I won't need the pistons. 

 

They are just garden variety Brembo brakes so there ought to be some outlet for Brembo parts somewhere. 

 

I'm wondering if anyone knows where it is.  I tried Max BMW and left a message for parts at Ted Porter. 

dc

[David13]

I'm ready to complete the rear brake caliper rebuild with the BMW seals.  I don't need the pistons, they are fine.

 

What I can't determine, is, if there is a right side to go up with the seals.

 

Sometimes they have one edge wider which should go down in the cylinder. 

 

I can't determine if they have that.

 

I'll also have that same issue with Ted Porter's Emerald Island aftermarket seals and pistons (which I probably won't need) for the front calipers.

 

Does anyone know how to determine that?  I tried feeling the old ones.  I can't see anything different on the new ones.

dc

[dirtrider]

On ‎5‎/‎15‎/‎2019 at 9:49 AM, David13 said:

I'm ready to complete the rear brake caliper rebuild with the BMW seals.  I don't need the pistons, they are fine.

 

What I can't determine, is, if there is a right side to go up with the seals.

 

Sometimes they have one edge wider which should go down in the cylinder. 

 

I can't determine if they have that.

 

I'll also have that same issue with Ted Porter's Emerald Island aftermarket seals and pistons (which I probably won't need) for the front calipers.

 

Does anyone know how to determine that?  I tried feeling the old ones.  I can't see anything different on the new ones.

dc

 

Evening David13

 

I can't tell you but can comment on brake piston seals. Some are cut square & will go in either way & others have a slight taper cut  & those need to go in in with the taper pointing in the same directions as the removed ones. (get a strong magnifying glass on them to look)

[David13]

That was all the information I got from the internet. 

 

Some go only one way, and some are directional.

 

With the looking glass I could see nothing on the new ones. 

 

In feeling the old ones I could feel the edge as I pulled my finger out of the bore.  When I took the old ones out they looked only a tiny bit more to one side.  Which I attribute to the pistons pulling against them for years. 

 

Putting the new ones in, they had that same feeling, that the inner edge was sticking up.  So maybe the ring cuts are angled in some way.  Doesn't seem like it could be, but ...

 

I'll see how they work.

dc

[dirtrider]

11 hours ago, David13 said:

That was all the information I got from the internet. 

 

Some go only one way, and some are directional.

 

With the looking glass I could see nothing on the new ones. 

 

In feeling the old ones I could feel the edge as I pulled my finger out of the bore.  When I took the old ones out they looked only a tiny bit more to one side.  Which I attribute to the pistons pulling against them for years. 

 

Putting the new ones in, they had that same feeling, that the inner edge was sticking up.  So maybe the ring cuts are angled in some way.  Doesn't seem like it could be, but ...

 

I'll see how they work.

dc

 

 

Morning  David13

 

That angle cut has more to do with (slight) piston retraction than sealing.