Rear caliper overhaul

[stolzy]

My rear pads have gone from new to metal in about 3000km. Before you ask, no, I haven't been dragging the rear, my trusted compadres would be more than willing to let me know if my brakelight was on

Removing the caliper reveals that one of the pistons is quite tight, not stuck, but distincly tighter than the other.

So I see new piston seals etc in my future.

My question regards bleeding them - the brakes are abs/servo, does that make them impossbly difficult to bleed? Or do these issues not affect bleeding just the rear?

Ta in advance

 

[Packer]

1150 GS with Servo/ABS means that you have to take the tank off to bleed the brakes.

There are photo's and write-ups on here but basically set up a bleeding tube on the caliper as for normal brakes, remove the tank, open the rear filler on the servo unit, ensure the reservoir is full, switch on the ignition and work the rear brake lever. Top up the servo reservoir as required.

DOT 4 fluid

P.S. If the fuel tank is full it weighs around 30Kgs for a standard bike and 40Kgs for a GSA. Moral? Use the fuel up first or drain most of it into something else.

 

[ELIMINATOR]

Try popping it out a bit and cleaning it up, before going the route of putting in new seals. when you've done this and if they both move easily, put a thin smear of red rubber grease around the piston / caliper interface. this should slow down the crap that gets into the caliper.

 

[Popeye]

If you're running servo/ABS make sure you are using sintered pads - standard pads seem to wear in the mileage you've indicated.

 

[stolzy]

If you're running servo/ABS make sure you are using sintered pads - standard pads seem to wear in the mileage you've indicated.

Ferodo Platinum. Same as I had on before - previous pair lasted 2 years/20K km. These lasted 3 months/3k km.

 

[Aidjay]

Try popping it out a bit and cleaning it up, before going the route of putting in new seals. when you've done this and if they both move easily, put a thin smear of red rubber grease around the piston / caliper interface. this should slow down the crap that gets into the caliper.

Would something like WD40 or AC-50 be good for this to free up the movement?

 

[stolzy]

Try popping it out a bit and cleaning it up, before going the route of putting in new seals. when you've done this and if they both move easily, put a thin smear of red rubber grease around the piston / caliper interface. this should slow down the crap that gets into the caliper.

I'll certaibnly try that, but how far can I pop them out before all the fluid ends up on the floor?

 

[CHANGELING]

IMHO you need to change the two rubber parts that protect the pins on the bracket and interface with the caliper as these swell with time and improper lubricants. You can buy a BMW kit with two rubbers and some silicon lube for about a tenner and it will work wonders for your problem young man.

 

[ELIMINATOR]

Aidjay, No do not put WD40 or ACF50 near the seald or pistons. there are far better products to use.

In theory just pop them out a little at a time, a ring of "crud" will be revealed, remove this with a toothbrush, brake cleaner aerosol, scotchbrite, etc.