Rear Brake seems to 'hang onto' the rotor...

chiller

Chowdah Ridah
Joined
May 13, 2006
Messages
250
Location
Mississauga, Ontario
Bike
ST1300
STOC #
Forgot
So I changed my tire this afternoon, put the wheel back in and button everything back together... tire spins fine...

I took it for a quick test spin and came back. I 'feel' like I'm using more clutch to get it moving from a stop. I put it on the center stand and spin the rear wheel, it does NOT spin easily. Also the caliper feels warmer then the front. So I put a screwdriver in between the pad and rotor and push the pads back in just a tad. Tire spins fine again ! If I tap the rear brake pedal it activates the brake but again doesn't want to "let go" ...

My bike is still under warranty with about 130k km = 80k miles on her. Wonder if this is a caliper issue or something else ? brake bleed was done about 2 months ago and was riding fine for a while (including a trip between then and now)

thoughts ?
 
chiller said:
So I changed my tire this afternoon, put the wheel back in and button everything back together... tire spins fine...

I took it for a quick test spin and came back. I 'feel' like I'm using more clutch to get it moving from a stop. I put it on the center stand and spin the rear wheel, it does NOT spin easily. Also the caliper feels warmer then the front. So I put a screwdriver in between the pad and rotor and push the pads back in just a tad. Tire spins fine again ! If I tap the rear brake pedal it activates the brake but again doesn't want to "let go" ...

My bike is still under warranty with about 130k km = 80k miles on her. Wonder if this is a caliper issue or something else ? brake bleed was done about 2 months ago and was riding fine for a while (including a trip between then and now)

thoughts ?
Click to expand...
Put on Center-stand, Stomp on rear brake peddle and then spin tire. If tire spins better then it is most likely the SMC sticking. Sometimes hitting just the rear break will release a sticking SMC. Yes it could also be the rear caliper not fully retracting.
 
I would take the caliper off and make sure that the pad and clips are installed correctly. If it was ok before the tire change I would not bet on a problem with the smc. Also the smc is not activated when the bike is on the stand.
 
woodybelle said:
I would take the caliper off and make sure that the pad and clips are installed correctly. If it was ok before the tire change I would not bet on a problem with the smc...
Click to expand...

+1 - then check smc, then check for dirt on the calliper pistons as not everyone cleans them that well if they don't fully remove the calliper at pad change (guilty! - as are most STealers) to access the more dificult to reach bits; then the dirt gets into the seals with the newly retracted pistons.

woodybelle said:
...Also the smc is not activated when the bike is on the stand.
Click to expand...

It is if you, or better a friend compress the smc by hand. (There's a method to use a car jack to lift the calliper while on side stand but after bitter experience I'd suggest DON'T unless you have a spare set of forks handy).

The stand has no link to the brake performance - except you ain't going anywhere if you keep it down...;)
 
I fixed it today ... I think my caliper pins were sticking ... I lubed it and torqued it back down and now EVERYTHING is smooth again ...

I did take the pads out, and sprayed brake cleaner on the caliper pistons and cleaned them off ... i checked the SMC and it was moving so I didn't think it was that, but I shot some brake cleaner down and into the hole just to be sure that the drain hole was cleaned out.
 
Mine is doing the same thing, I've got 51k (miles) on the clock and changed the pads 4k ago, I have yet to get up-close-&-personal with the caliper but it looks like the left pad friction material is poluting the air in Germany (I've just got back from there) and the right pad is OK, I have invested in a caliper servicing kit and intend to overhaul it later this week, I noticed it after my fuel consumtion went up and I only got 300 miles from a tank full instead of the normal 370 i get for normal motorway driving:(
 
chiller said:
I fixed it today ... I think my caliper pins were sticking ... I lubed it and torqued it back down and now EVERYTHING is smooth again ...

I did take the pads out, and sprayed brake cleaner on the caliper pistons and cleaned them off ... i checked the SMC and it was moving so I didn't think it was that, but I shot some brake cleaner down and into the hole just to be sure that the drain hole was cleaned out.
Click to expand...

Brake cleaner is gonna eat up the seals. If the pads were changed and they didn't scrub the exposed pistons with brake FLUID you may have pushed gunk bank into the seal with the new (thicker) pads, causing them to stick a little. Also clean lube the caliper slide and hanger pin with silicone brake grease (dielectric grease).
 
Brake Cleaner should not be used to clean anything near the calipers! It will swell and ruin the seals in a matter of seconds.
You can use windex or simple green and a small pain brush to clean the area. then use brake fluid and a tooth brush to clean the pistons etc. As said prior, don't push the dirt into the system.
Glad you solved your problem...hope you didn't create another....JUst sayin'
Ride safe
 
chiller said:
Just curious , why do they call it brake cleaner if its not meant to clean brakes ? (maybe I'm asking a dumb question)
Click to expand...

It is to clean any oils or other deposits off the rotors. Should some oil or grease get up on them from a leaking fork seal or something. The brake cleaner has chemicals in it to clean away the oils and not leave any residue behind.

It isn't good to clean the caliper pistons with it as you can push some of the cleaner back into the brake fluid and on the piston seals when the pistons are pushed back in the caliper. This can damage the piston seals over time as it is harsh on them and contaminate the brake fluid. Doing it a couple times won't likley do any major damage but not good practice. When you clean with brake fluid if any works past the seals you get brake fluid in contact with brake fluid. No harm there and the seals are designed to be resistant to brake fluid so it won't harm them.

I wouldn't go back and reclean with brake fluid. Just keep in mind for next time.
 
You must log in or register to reply here.
Back
Top Bottom