Pointy Rear Brake - play in front slide pin

[aesmith]

Hi,

I've always had a problem with the rear brake, typically it only wears the piston side pad, sometimes it sticks even though everything is perfectly free when tested separately. I think the problem is caused by play between the front sliding pin and the carrier, meaning that the calliper doesn't slide in a straight line.

Two questions, firstly does the panel think that this could be the cause? There's definitely play in that front pin, but I'm just assuming that it should be a tight sliding fit. I can see the calliper moving unevenly when I press the pedal.

Secondly, is there anyway of fixing this other than by replacing the carrier?

Thanks,
Tony S

[Red ones]

I can't answer the question, however I can give a word of warning.

The caliper and carrier bracket for the rear brake comes as a matched pair and cannot be bought separately.

I would not recommend buying a secondhand caliper carrier because they can get easily bent changing the back wheel.

[Blapper]

Have you overhauled the rear caliper lately? I am just thinking that a seized piston could cause a twisting action and make the caliper bind up instead of sliding.

[Bibio]

sounds like you have a bent carrier bracket. its rare for pointy rear callipers to seize due to the piston seal recesses being anodised.

some of the problems i have seen in the past is the rear piston side shim gets corroded and the inner layer breaks up. not fitting the pads on the forward location shim properly, the shim has small tabs that can cause the pads to jam. cross threaded bolts.

most of the time its badly fitted pads on the carrier shim and yes i have also been guilty of doing it myself.

[aesmith]

Cheers all. I notice that Suzuki sell the bracket separately, so I'm not sure it can be true that they're a matched pair not to be sold separately.

I checked this all out as best I could just recently, when refitting the rear calliper after stripping and rebuilding. The piston was still moving and letting off, but getting sticky. With the calliper fitted but without pads, it can slide freely but only if I take care to move it while keeping it square. It really wants to go squint which then jams.

From what you guys say it sounds like play in the front pin isn't an issue in itself?

I'm guessing that there's not going to be any way to straighten the bracket, so I suppose it's time to check Ebay and make sure the seller's clear that it's not bent.

[Bibio]

Originally Posted by aesmith

I checked this all out as best I could just recently, when refitting the rear calliper after stripping and rebuilding. The piston was still moving and letting off, but getting sticky. With the calliper fitted but without pads, it can slide freely but only if I take care to move it while keeping it square. It really wants to go squint which then jams.

.

if i'm reading this right and the piston is getting sticky and moving squint then you have a twisted piston seal.

[aesmith]

Sorry I must have been unclear. The piston is now completely free, calliper has been rebuilt. Prior to rebuild it was reaching the stage that it needed a bit of force to push it back, although operation was still more or less normal.

It's the calliper itself the goes squint when the brake is applied, or if I move the calliper when it's fitted to the carrier but without the pads installed and try sliding it in or out.

[Bibio]

there is a tiny bit of play but not that much. i would suggests that you have fitted it wrong and will stick my neck out and say that the pads are catching on a shim. TBH unless i had a look then it could be a number of things.

these are the main things that are fitted wrong or needs replaced:
brakes.jpg

number 1:
people put this the wrong way round so jams the pads. yes it only goes one way but can be put in the wrong way. the smaller of the 'prongs' fits on the immovable pad opposite the piston side pad which has the longer 'prongs'.

number 2:
when refitting people dont get the pad lobes in the correct position again jamming the pads. there are small uprisings on the shim which people tend to get the tab of the pads caught on.

number 3:
the rubber bush gets perished so causes the calliper to move on the metal bush insert which causes excessive play.

[aesmith]

Thanks. A few things to check there, some of which I'm sure I've already checked in the past but no harm in going through them all again. No1 isn't something I've checked before.

[aesmith]

After a couple of days use, around 125 miles, the pads are now more or less bedded in. The amount of movement is now so small I can't really see if the calliper's staying square or going squint (when first fitted the front was clearly moving more than the back). The acid test will be whether the pads wear evenly but that won't be apparent for quite some time.