rear brakes sticking

[Ghostdad]

I just had my 1100RT into the dealership for tires on Saturday and when they pulled the rear tire they found the rear pads shot. I thought I had heard a faint squeal once or twice the previous days. Well they put in a new set and now they seem to be sticking and the rotor is too hot to hold on to. I searched for topics on this prior to posting and had no luck finding anything.

I recall reading posts about a pins that gets rusty and holds the pad against the rotor.

My question is : is the pad retaining pin the one everyone is talking about or is it a different pin?? And if it is the retaining pin can I pull the pin without removing the rotor or should I pull and check the rotor anyways???

I'm not blaming the dealer since I'm sure it is something that is probably easy to fix and more than likely not easy noticeable at the time of the work...

In fact I'm quite satisfied with the way the dealership handled the whole thing since they got me in fairly quickly without an appointment..

Any and all help and suggestions appreciated..

Thanks in Advance

Dave

[DEF]

The dealer did not properly serice the caliper when they replaced the pads. Any time the pads are replaced, the caliper should be split, cleaned and the pins greased.

 

Remove the caliper and remove the pads. Pull apart the two halves of the caliper exposing the pins (under the rubber boots). Clean these pins and lube them sparingly with a light application of grease. Reassemble and refit the caliper....problem solved.

[Jerry Duke]

You'll need a rebuild kit. There's two small O-rings that if you're not careful will need to be replaced if you split the caliper.

[Hedge36]

The retaining pin on the rear of the caliper should be pulled, brass-brushed and lubed with brake grease at each oil change as a preventive measure, more often if you ride in the rain a lot. The pin gets gunked up and makes the pads drag, shortening their lives. Known issue.

[Ghostdad]

So if I split the caliper halves I need to get a rebuild kit for the o-rings? What kind of grease should I use to grease the pins? Wheel bearing grease or moly grease?

Or is it the retaining pins on the back of the caliper that is causing the problem???

Just trying to figure this out so if I need to go to the dealership I can before I have torn down.

Thanks

Dave

[Hedge36]

Unless you have a specific reason to split the caliper, I'm betting that you just need to clean things up and polish up the pin. Use brake grease, comes in a little tube at the local parts haus (Pep Boys, Autozone, et cetera). Just a dab'll do ya.

[philbytx]

BMW recommends Shell Retinax A, which isn't listed in the Shell catalogue for the U.S.!

Checking their website for applications, it appears that Shell Retinax LX (2) is the appropriate grease or really, any other Lithium based NLGI 2 ASTM GC-LB grease with excellent water wash off resistance and high temp properties...I'll simply use Mobil1 grease as I use it on my RV zerk fittings

[RFW]

So if I split the caliper halves I need to get a rebuild kit for the o-rings? What kind of grease should I use to grease the pins? Wheel bearing grease or moly grease?

You will only need a rebuild kit (a few O-rings and piston seals that BMW charges obscene prices for) if the rubber parts are damaged.

 

As for grease, the best BY FAR is Dow Corning #4 or #111 silicone grease. This stuff is totally unaffected by water and withstands extreme heat. Regular grease is not recommended because it is affected by water.

[DEF]

So if I split the caliper halves I need to get a rebuild kit for the o-rings? What kind of grease should I use to grease the pins? Wheel bearing grease or moly grease?

Or is it the retaining pins on the back of the caliper that is causing the problem???

Just trying to figure this out so if I need to go to the dealership I can before I have torn down.

Thanks

Dave

 

 

No-no-no....do not open the hydraulic portion of the caliper....split the two halves..just do the following.

 

1- Remove the brake line.

2- Remove the caliper.

3- Remove the pads and other hardware.

4- Take the two halves apart from one another...just pull on the two halves.......the caliper will part accordingly.

5- Grease the now exposed pins. I use the same grease I use for the splines. Caution, do not get grease on any friction surface.

6- Reassembly is the reverse.

7- Reinstall the caliper.

8- Reinstall the brake line.

9- Bleed the caliper.

10- Refill the rear brake reservoir.

 

Some added information, your caliper is attached to the rear drive by what I will call the mounting bracket. The caliper floats back and forth on the pins attached to this bracket. Remove the bracket from the caliper. This will expose the pins in questions.

 

Follow instruction above.

[Ghostdad]

1- Remove the brake line.

2- Remove the caliper.

3- Remove the pads and other hardware.

4- Take the two halves apart from one another...just pull on the two halves.......the caliper will part accordingly.

5- Grease the now exposed pins. I use the same grease I use for the splines. Caution, do not get grease on any friction surface.

6- Reassembly is the reverse.

7- Reinstall the caliper.

8- Reinstall the brake line.

9- Bleed the caliper.

10- Refill the rear brake reservoir.

 

 

 

 

Thanks for the clarification. I will pick up some brake fluid tomorrow and fix it then. Is the spline grease your talking about a moly grease by chance? It seems to be what everyone recomends for splines.

Thanks for yours and everyones help. This D.B is great and full of knowledgeable and helpfull folks. Thanks again

 

Dave

[RFW]

No-no-no....do not open the hydraulic portion of the caliper....split the two halves..just do the following.

You had me going there for a moment, Dennis. With my old K100's Brembo brakes, splitting the caliper automatically gets you into the hydraulic system, since it has 2 opposing pistons and a rigidly mounted caliper. THere is an o-ring seal between the caliper halves.

 

Then I noticed your last paragraph, which implies the calipers on the bike in question, are floating types with piston(s) on only one side. Is this correct?

[Joe Frickin' Friday]

Then I noticed your last paragraph, which implies the calipers on the bike in question, are floating types with piston(s) on only one side. Is this correct?

 

R1100RT, rear caliper, has pistons on one side only; the caliper floats on guide pins.

 

I haven't looked at it, but as I was reading this thread I thought it odd that one would have to break into the hydraulics in order to service those guide pins.

[DEF]

No-no-no....do not open the hydraulic portion of the caliper....split the two halves..just do the following.

You had me going there for a moment, Dennis. With my old K100's Brembo brakes, splitting the caliper automatically gets you into the hydraulic system, since it has 2 opposing pistons and a rigidly mounted caliper. THere is an o-ring seal between the caliper halves.

 

Then I noticed your last paragraph, which implies the calipers on the bike in question, are floating types with piston(s) on only one side. Is this correct?

 

Yes....one side pistons only.

 

Once you remove your caliper from the bike, the dissasembly, lubing the pins, etc. will be intuitive.

 

Sorry, my original instructions were vague and missleading. I often assume people know what I am speaking of when I post a proceedure...........that is not a good idea.

 

I'll try to be more informative and explain things better in future posts.

[RFW]

I'll try to be more informative and explain things better in future posts.

No biggie! This was more a problem with my unfamiliarity with the specific bike in question than anything else. As you said, one you have the caliper on the bench in front of you, the whole thing becomes pretty clear.

[Ghostdad]

Alright I pulled apart the caliper per your intructions,( except changing the brake fluid), cleaned and greased the pins. Went for a test ride after I was done and still the same problem.

Any other suggestions??

Dave

[Davis]

Have you checked to make sure the pushrod between the brake pedal and the master cylinder isn't misadjusted and applying the brake? If that's not it and it isn't the caliper sticking on the guide pins or the pads sticking on the retaining pin, then about all that's left is the pistons in the caliper sticking.

[Ghostdad]

Have you checked to make sure the pushrod between the brake pedal and the master cylinder isn't misadjusted and applying the brake? If that's not it and it isn't the caliper sticking on the guide pins or the pads sticking on the retaining pin, then about all that's left is the pistons in the caliper sticking.

 

 

 

That rod shouldn't need adjustment just because new pads were installed should it?

If it is the pistons sticking, how difficult is to to disassemble and repair?

Dave

[Joe Frickin' Friday]

That rod shouldn't need adjustment just because new pads were installed should it?

 

If the dealer was able to push the pistons back in in order to install the new pads, that means the bleed port in the master cylinder was not being covered by the master piston when the pedal was unpressed. All of that is to say that your brake pedal and pushrod/master cylinder appear to be in proper adjustment (it does not need to be adjusted based on pad thickness).

 

I think your caliper's slave pistons are sticking in their bores. Try pushing them back in their bores a bit: grab the left side of the rotor with your fingers, and the right side of the caliper with your thumbs, and squeeze. Verify that you've created some clearance and that the wheel spins freely. Now go for a short ride (yes, use the rear brake normally), pop the bike on the centerstand, and check rear wheel spin again. It's normal for the brake to rub a little bit and be warm to the touch, but even with driveline friction you ought to be able to get the rear wheel to spin for a rev or two with a good shove.

 

How many miles on the bike?

[Ken H.]

they seem to be sticking and the rotor is too hot to hold on to.

Just to be sure we are not chasing a ghost problem here...

 

When you say sticking, with the bike on the center stand, can the rear wheel be rotated easily by hand? A bit of brake drag is normal. OTOH the wheel shouldn't be 'stiff' to rotate.

 

With the brakes stone cold, go for a 15 min. or so ride and use NO rear braking at all during it. Is the rear disk then too hot to touch, or just somewhat warm?

 

What pads did you/they put back on it? Some aftermarket ones have notoriously low clearance when new.

[Ghostdad]

Alright to answer your questions: the bike has 42000 miles. As far as what pads they put on I'm not sure the part # on the invoice is 4542410 if that helps?

it seems a little better after cleaning and greasing the pins. Now you can almost hold onto the rotor after riding. I realize the rear rotor will not be a cool as the front rotors after a ride (because of the heat from the final drive) but they shouldn't be so hot that you can't hold onto them should they?

I ordered a seal kit today, I should have it tomorrow. I just unbolted the caliper and removed the pads and tried lightly pressing on the brake pedal. Only the rear piston moves out, the front piston will move if I hold the rear piston while pressing the brakes. When I let off the pressure on the pedal the pistons retract a slight bit (maybe 30thousandths of an inch).

Any other suggestions or should I go ahead and replace the O-rings and seals?

Thanks

Dave

[DEF]

Alright to answer your questions: the bike has 42000 miles. As far as what pads they put on I'm not sure the part # on the invoice is 4542410 if that helps?

it seems a little better after cleaning and greasing the pins. Now you can almost hold onto the rotor after riding. I realize the rear rotor will not be a cool as the front rotors after a ride (because of the heat from the final drive) but they shouldn't be so hot that you can't hold onto them should they?

I ordered a seal kit today, I should have it tomorrow. I just unbolted the caliper and removed the pads and tried lightly pressing on the brake pedal. Only the rear piston moves out, the front piston will move if I hold the rear piston while pressing the brakes. When I let off the pressure on the pedal the pistons retract a slight bit (maybe 30thousandths of an inch).

Any other suggestions or should I go ahead and replace the O-rings and seals?

Thanks

Dave

 

Sounds as if the DOT4 was neglected. Remove the brake line, Remove the caliper and remove the pads. Remove the pistons. Examine them, If there is any rust, the caliper needs a rebuild. If the pistons and caliper merely show signs of junk, dirt and sludgy DOT4, thoroughly clean with brake cleaner. Wet the pistons with DOT4 and resinsert them into the caliper. They should move freely and not stick in any position. If all is well, reassemble and instal and thoroughly bleed the caliper using fresh DOT4.

[Ghostdad]

All is good again.. I popped the pistons out and cleaned everything real good and replaced the seals. Well all but one dust seal, The seal kit I got from the dealer had one off size dust seal. So I picked the best looking old one and cleaned it good and reinstalled it. Everything is working fine now. I just need to bleed the brakes again I got a little air in the line but other than that all is well...

Thanks agin to everyone for helping and heading me in the right direction to fix the problem. This place is full of top notch people. The more work I do myself the more knowledge and confidence I gain and know that with the collective knowledge of this board I should be able fix almost any problem myself....

It's nice to have my bike back on the road and just in time for the weekend.

Thanks again.

Dave

[DEF]

All is good again.. I popped the pistons out and cleaned everything real good and replaced the seals. Well all but one dust seal, The seal kit I got from the dealer had one off size dust seal. So I picked the best looking old one and cleaned it good and reinstalled it. Everything is working fine now. I just need to bleed the brakes again I got a little air in the line but other than that all is well...

Thanks agin to everyone for helping and heading me in the right direction to fix the problem. This place is full of top notch people. The more work I do myself the more knowledge and confidence I gain and know that with the collective knowledge of this board I should be able fix almost any problem myself....

It's nice to have my bike back on the road and just in time for the weekend.

Thanks again.

Dave

 

Dave,

 

Job well done.......you have tackled one of the most difficult repairs on a motorcycle with excellent results.

 

And while brakes do not have the many precision sufaces, bearings, splines like other parts of the bike, brakes are THE most important system on your motorcycle......without good brakes, you're dead (or seriously injured).

 

The secret (no secret really) to long brake service is bleed and refill the system annualy with fresh DOT4 to remove water and other contaminants.....

 

So, next time you need a repair or maintenance procedure, call on us here......someone has first-hand experience and can help.......Next, spline lube......think about it!

 

Now, go ride........