Rear brake locked up?

[Guest]

I took my rear tire off to replace the sprocket and tire. When putting the caliper back on the rotor the pads wouldn't separate. I had to force them apart to seat on the rotor. Now the rear tire won't spin at all. Am I doing something wrong?

[chef1366]

Take it off and push the piston in with a c-clamp.
Put it together and pump the brake until it gets stiff.

[GS650E_81]

Take it off and push the piston in with a c-clamp.
Put it together and pump the brake until it gets stiff.

I assume I have to take off the brake pads first?

[BassCliff]

Hi,

You can leave the pads in if you are careful not to damage them while you force them apart. Use something to cover the pads.

What maintenance have you done to the brake system? Have you replaced the brake fluid (bled the lines until all the old fluid is gone)? Have you rebuilt the calipers or master cylinder? These are all very important tasks that must be addressed. Don't ride on 30 year old brakes.


Thank you for your indulgence,

BassCliff

[chuck hahn]

Are the proper washers on the bolts..if not the bolt can screw in too far and jam against thr rotors.

[GS650E_81]

Are the proper washers on the bolts..if not the bolt can screw in too far and jam against thr rotors.

My bolts don't appear to have any washers and I checked to see if they were hitting the rotor and they are not.

The pads appear to be locked together hard from the top looking down. I will try and get them out and try again.


I really didn't want to have to bleed the system and rebuild the calipers, but I guess I better. Looks like I won't be riding this summer

[chuck hahn]

Pry them open off the rotor and just pull them apart and clean the entire caliper and reassemble it. Take the seals out carefully and clean them. I use my fingernail to gently go around and scrape them clean from any stuck on gunk..then wash them with some hot soapy water and towel dry them. Then use a dremel and the little wire brush and clean the groove the seal goes into. The common problem is that scale builds up around and behind the seals in the grooves. This creates the need for something to be displaced and that would be the seal. This pressure causes the seals to gorilla grip the piston and your at the point you are now. If you simply disassemble it and clean the seals and grooves youll most likely have good brakes again..Its only a hr or so worth of work. Be sure tht you smear a bit of brake fluid on the seals and pistons before you slip them back in.

[GS650E_81]

Pry them open off the rotor and just pull them apart and clean the entire caliper and reassemble it. Take the seals out carefully and clean them. I use my fingernail to gently go around and scrape them clean from any stuck on gunk..then wash them with some hot soapy water and towel dry them. Then use a dremel and the little wire brush and clean the groove the seal goes into. The common problem is that scale builds up around and behind the seals in the grooves. This creates the need for something to be displaced and that would be the seal. This pressure causes the seals to gorilla grip the piston and your at the point you are now. If you simply disassemble it and clean the seals and grooves youll most likely have good brakes again..Its only a hr or so worth of work. Be sure tht you smear a bit of brake fluid on the seals and pistons before you slip them back in.

Any way to get the piston out without using compressed air? As I don't have a air compressor. Might as well do a complete cleaning if I am going to go this far..

[chuck hahn]

Take the caliper off the rotor but DONT break the banjo bolts. Remove the pads and the pistons will now be wide open. Get a piece of about 1/2 inch thick wood and a few other thinner pieces..like say 1/8 strap steel shims. Next insert the wood with a shim or two ( whatever fits in the caliper) then pump the foot lever and the hydraulic pressure will push the pistons out to the shims. Remove the 1/8 inch pieces and pump some more. The idea is to get the pistons out as far as you can without actually dislodging them from the caliper. Then you remove the caliper from the brake line, undo the 2 allen heads that hold the 2 halves together and you can wrap something around the pistons to prevent any scars and use some channel locks to get them the rest of the way out. You can grip them by the very end just above the groove the dust boots go in also and kinda twist and pull out at the same time. You just dont want to scar anything below that groove though.

[chuck hahn]

I probably should add that the pistons arent that deep in the calipers..maybe around 3/4 inch or so. guage how far your getting them out and make a call as to how far is enough..then grip them and twist them the rest of the way out.

[GS650E_81]

I loosened up the bolts that hold the caliper to the rotor. That seemed to work. The wheel would spin freely.

The problem is I was riding Saturday morning and the back brake went out. I looked at the caliper. One of the bolts is missing!

I assume since I cannot tighten them down all the way one vibrated out. So now I think I may have to lock-tite them so they stick? Confused as to why when I tighten down the caliper snug, the wheel does not move...

[Steve]

I would figure that out before riding the bike again.

Riding around with intentionally loose brake parts is qualifying yourself for a Darwin Award.

.

[Nessism]

Dude, fix the bike before you wind up dead.

Pull off the caliper and then remove the pads. Hold the caliper in your hand and gently pump the brake pedal and watch the pistons come out. Try to get both pistons to come out equally (push the one that is coming out faster back in some. In the end you want both pistons to pop out of their bores at roughly the same time. Brake fluid will go everywhere so be ready for that. If one piston is still in the bore, carefully pry it out - use two screwdrivers at 180 degrees from each other around the piston, prying up in the dust boot groove.

Once you get the piston out inspect all the parts and clean out the crud. I strongly advise you to take the master cylinder apart too, and replace the brake line. The entire job will only take about 1/2 day assuming you gather all the parts and tools together first.

Good luck and please be safe.

[GS650E_81]

Dude, fix the bike before you wind up dead.

Pull off the caliper and then remove the pads. Hold the caliper in your hand and gently pump the brake pedal and watch the pistons come out. Try to get both pistons to come out equally (push the one that is coming out faster back in some. In the end you want both pistons to pop out of their bores at roughly the same time. Brake fluid will go everywhere so be ready for that. If one piston is still in the bore, carefully pry it out - use two screwdrivers at 180 degrees from each other around the piston, prying up in the dust boot groove.

Once you get the piston out inspect all the parts and clean out the crud. I strongly advise you to take the master cylinder apart too, and replace the brake line. The entire job will only take about 1/2 day assuming you gather all the parts and tools together first.

Good luck and please be safe.

Thanks.

Advised I am brand new to working on brake systems. Can I just order a replacement brake line from gssuzuki.com or something like that? Or will any brake line work?

I know SS brake line is supposed to be good as well. Can that be used for the rear brake?

I am going to take the caliper apart tonight and see whats going on.

Thanks for your input.

[GS650E_81]

Also, does anyone have a picture of the rear master cylinder with the lid off? Mine has a rubber housing but it appears to be dirty and is sitting on top of the brake fluid. Is brake fluid suppose to be in the rubber housing or under it?

Noob