Rear brake pad replacement

[xman]

My rear rotor was fairley warm after a ride.  Fronts were cold. When I got it on the lift,  there was a bit of grinding noise and a bit of drag. And fair amount of brake dust. It was hard to see what's left of the pad, so I ordered pads and the seals for the two pistols. 28k on the bike and never had brakes.

So when you do pads do you clean up the piston and push them back in?  Or push out the pistons and replace the seals?

[Brewer]

I push the pistons back in if the seals are not leaking I leave them.

I also test the caliper movement on the slides, it should move side to side for re centering (even wear for the pads).

This is what I was taught for car brakes. If one of our MC experts has a different view I am sure they will chime in.

[BobB]

Pull out your current pads and push the cylinders in to get clearance for the new pads.  I use a c-clamp for that.  Put in the new pads and run them for a few miles.  This brake should not drag and heat up but the pads have to be run in.  If dragging, then a complete rebuild is required with new seals.  There is plenty of information here on how to proceed.

Brewer is right about checking the self align movement, that can be lubercated...

[cookiedough]

I've got 30K on my Valk I/S same OEM pads from 2001.  I just ordered new pads all around since last few years I have noticed my rear pads do not bite/grip and slow down the bike like they use to some 4-5 years ago.  Front brake pads work well still though and from what I see looks pretty darn good still can see visually with flashlight shining on them see the 3 grooves still in them showing and working well still.  I use the rear brake pad more often than front to slow down more gently adn don't see anymore wear bars/grooves left at all.  The rear pads don't look too good so will be replacing them more than likely when I get the new rear tire mounted soon, but will leave it up to the tech to see what he thinks on front brake pads since look o.k. to me yet until 1-2 more years from now when I need a new front tire.  

[hubcapsc]

I cleaned the exposed parts of these pistons and then
pushed them out some... that contamination you
see is what gets pushed back into the caliper if you
don't push the pistons out far enough to clean them
all the way, or take them out to clean them and replace
the seals...



I always take the calipers apart and clean everything up like new
when I change the pads...



-Mike

[xman]

Thanks, I'll try the easy pad replacement. If there's drag when I get done,  I will have the seals to redo it.

[Rio Wil]

It would probably also be a good idea to remove the rear brake pedal and clean and re-lube the pivot bolt...they tend to crud up over the years......you will be surprised how much more useful rear braking becomes.....

[old2soon]

You've ALREADY got it off go ahead and rebuild it while it's off. NOT that hard. Couple years ago I was checking my I/S before a ride. Rear brake locked up and would not release. After removing the pistons have a look at the bores. Polish up the exposed part of the pistons new seals and be done with it. It's your brakes. Have a look t that flex hose back there. If there is the slightest doubt-replace it to. Again-it's your brakes. RIDE SAE.

[Valkpilot]

Make sure your pads are moving freely on the retaining pin.  A little sanding and a light coat of high-temp grease on the pin will keep the brakes from dragging.

[Chrisj CMA]

If the brakes are operating properly, I would wonder why the rear rotor was warmer than the fronts.  If you use the rear more than the front during normal driving conditions, you are asking for trouble

[Joe Hummer]

When I have my rear wheel off, I usually take a brass wire brush to the pistons to clean them off before pushing them back into the caliper.  I use a pair of pliers to rotate the pistons...just grip the edge and twist.  They usually move pretty easily.  You can also use fine grit sandpaper and wrap it around to clean.  I have 145k on my original calipers/pistons and never had issues.  Definitely check the pivot point for the brake pedal.  While it shouldn't cause the pads to rub, it will make working the brakes much better.  Lastly, check your feet placement to make sure you aren't resting your foot on the pedal while riding.   

ChrisJ...you aren't asking for trouble if you use your rear brakes more than your front...as long as you don't overdo the amount of rear brake given at any one time.  The best braking is with both at the same time.  You just have to remember to stand the bike upright before applying a lot of brakes. 

Joe

[F6Viking]

A couple of years ago I noticed a huge reduction in slowing/stopping when getting on the rear brake.
What I found was that the pistons had almost seized and would barely move, if at all. It took quite a bit of work to get the pistons pulled out without damaging the calliper itself. I had to clamp on the lip of the piston with vice-grip and would hammer on the vice-grip to loosen and pull the pistons out. A lot of Kroil and a little heat really helped. The piston cups were too rough on the edge of the lips to reuse them by the time they came out.

I ordered the seal/gasket sets along with new pistons then proceeded to clean up the calliper. I had to use a small wire wheel on a Dremel to get all the oxidation from around the calliper openings and the outside gasket groove. I was really fortunate that I caught it when I did and was able to successfully pull the old pistons and get the caliper cleaned and operational again without damaging or having to scrap the whole calliper.

Needless to say, this is now an item that I thoroughly clean, not just wipe the brake dust off of while it is removed while I have the rear wheel off doing the rear drive service.  

[Gunner]

I had a seized piston in a rear caliper.  After attempting to blow the piston out with air, and then soaking the whole works in Kroil, it still would not budge.  I took the end off the hose of my grease gun and found that I could screw the end of that hose into the caliper.  I then pumped that caliper full of grease and that piston walked right on out.  Surprised me and no damage.

Gunner

[F6Viking]

Wow, very ingenious. Amazing what we can come up with in a pinch. Hope to never be in that situation again but hopefully will remember the grease gun idea if someone else or myself would be there.