Rear brake pads replacement problem

[Dann]

I'm in the process of replacing my rear brake pads.

Everything went well until I tried to put the caliper back on the disk.

 

There is no way the pads will spread apart enough to fit over the disk (Which is at 5mm )

 

I removed almost all the fluid from the reservoir but it makes no difference.

 

The pads are EBC FA363HH which should be the right ones.

 

I've replaced my front pads last year with EBC ones with no issues.

 

I'm open to suggestions

 

 

[The Rocketman]

This might help:

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=937950#Post937950

[xoomerite]

Will the piston retract completely? If not, it may need to be cleaned or some debris removed to allow it to do so. I use two wooden construction shims to spread the pads apart. When installing new pads, I find that the pads must compress the piston completely in order for the fresh assembly to fit over the disc.

Chris

[Guest Kakugo]

Dann, I've had exactly the same problem not once, but twice, only the second time I knew exactly what the culprit was.

 

Those Brembo rear calipers are mounted on sliding pins which can rust solid. If the caliper cannot slide freely, you won't be able to fit new pads on the disc, no matter how hard you try.

The only solution is to take the caliper off its bracket, polish the sliding pin (usually only one is rusted) as much as you can, put a dab of brake grease on it and reassemble the whole thing.

If you have this problem, it will come back down the road, hence once you have to insert a polishing/greasing session once a year in your maintenance routine.

[Dann]

Dann, I've had exactly the same problem not once, but twice, only the second time I knew exactly what the culprit was.

 

Those Brembo rear calipers are mounted on sliding pins which can rust solid. If the caliper cannot slide freely, you won't be able to fit new pads on the disc, no matter how hard you try.

The only solution is to take the caliper off its bracket, polish the sliding pin (usually only one is rusted) as much as you can, put a dab of brake grease on it and reassemble the whole thing.

If you have this problem, it will come back down the road, hence once you have to insert a polishing/greasing session once a year in your maintenance routine.

 

By the sliding pins do you mean that silver bar attached to the caliper?

If so, it moves very easily.

 

Anyway, Thanks for your replies but unfortunately it's game over... (for now)

I ended up ruining the pads trying to spread them apart.

 

 

 

I reinstalled the old ones which still have a bit more than one bar left.

 

This is how much the pistons were pushed back. Could they still go more in?

 

 

 

No matter how much I tried, the fluid would not push back into the reservoir.

 

Next time i'll try with the bleeder valve open.

[Alfred02]

To me it looks like you have got the wrong brake pads!!

One of them is suppose to be thinner in brake material then the other pad. Looking at your photo, they look exactly the same material thickness and that would be WRONG.

 

[dirtrider]

Evening Daniel

 

That happens every now & then on the 1200RT--Some aftermarket pads are just a little too thick to fit when

new. (OEM rear pads have one slightly thinner pad)

 

 

If you are absolutely sure that the caliper pistons are FULLY retracted then you have a couple of choices.

 

Sand one pad thinner or sand both pads slightly thinner (usually doesn't take much)--Just make darn sure

that you get ALL the sanding grit of off the pads before installing. (if I have time I usually just mount

the inner pad in my Bridgport & take a little off the pad thickness)

 

 

Or if I don't have the time (or want to spend the energy) I just install one new brake pad & one of the

originals ( never had it not go back together that way). Then next tire change or in a few thousand miles

remove the original pad & install the other new brake pad.

 

On your banged up brake pads-- As long as the pad steel backings are not bent, Personally I would just sand

them a little on a very flat surface (like piece of glass) then use those. In a few thousand miles you will

never see those marks. (maybe not on the front but for rear brake pads I would not have any qualms using those).

 

 

 

 

 

[Bernie]

Dann, I've had exactly the same problem not once, but twice, only the second time I knew exactly what the culprit was.

 

Those Brembo rear calipers are mounted on sliding pins which can rust solid. If the caliper cannot slide freely, you won't be able to fit new pads on the disc, no matter how hard you try.

The only solution is to take the caliper off its bracket, polish the sliding pin (usually only one is rusted) as much as you can, put a dab of brake grease on it and reassemble the whole thing.

If you have this problem, it will come back down the road, hence once you have to insert a polishing/greasing session once a year in your maintenance routine.

 

By the sliding pins do you mean that silver bar attached to the caliper?

If so, it moves very easily.

 

Anyway, Thanks for your replies but unfortunately it's game over... (for now)

I ended up ruining the pads trying to spread them apart.

 

 

 

I reinstalled the old ones which still have a bit more than one bar left.

 

This is how much the pistons were pushed back. Could they still go more in?

 

 

 

No matter how much I tried, the fluid would not push back into the reservoir.

 

Next time i'll try with the bleeder valve open.

 

I think those pistons can retract another 1 or 2 millimeter.

When mine are fully retracted, they are lush with the housing.

And I would not worry about a few marks on the pad surface, as long as it is not cracked or covered in oil/grease.

[Bob_Minor]

Evening Daniel

 

Or if I don't have the time (or want to spend the energy) I just install one new brake pad & one of the

originals ( never had it not go back together that way). Then next tire change or in a few thousand miles

remove the original pad & install the other new brake pad.

 

 

 

Clever!

[Dann]

Latest update...

 

I'm pretty sure I found out what my problem was.

 

I had a hard time doing a brake bleed today. I could not get pressure from the pedal no matter how much I pumped.

So I figured that there must be something wrong with the line since I had some brake fluid but no air coming out.

 

The line under the rear reservoir was so twisted that the fluid could hardly go through.

 

The pistons could not be pushed back more because there was the fluid couldn't go back to the reservoir.

 

Every time you put the cover back on the rear brake reservoir, you have to make sure it doesn't turn. It's only held by a clip and can rotate easily.

 

I guess that after years of being twisted a little every time there was a brake bleed, the line got too twisted for the fluid to go through properly.

 

I'm going to leave my old pads on for a while since they had more life left than I thought. (They're not at the 3rd notch yet) and replace them later.