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Sticky brakes?

Posted: Thu Jun 23, 2005 10:45 pm
by Shifty
If you've been following the thread in General you will know that I have recently picked up a GPZ900. The front brakes have been machined, calipers rekitted and of course new brake pads.

The bike felt a bit funny into corners and I put that down to being a longer wheelbase and being much heavier than I was used to (an extra 48kg dry). Now, when I stopped at the servo on the way home, the bike was a bitch to push. At first I put it down to the weight of the bike, but that just didn't make sense as I could push my GPX600 around without any woes, but the GPZ900 I could harly move 10mm with all my might. So, I assumed the brakes were sticking.. and having ridden it all about the place it is definitely the front.

This makes corner entry funny (tried trailing the front brake all the way through a corner? well don't!) and it as absolutely impossible to reverse, even on slight hills. Sometimes it doesn't stick as much and I can push it a little (even when off the bike it is near immovable) so something really needs to be done!

As everything has been recently reco'd (last few months) I'm wondering what the issue is, andhow I might solve it. My current plan is to bleed the brakes & pull the calipers off, fully extend them and then recompress them half a dozen times in case they're just a bit toight (like a toiger).

Other suggestions (master cylinder?) would be welcomed.

Posted: Thu Jun 23, 2005 11:04 pm
by RG
erm...... how about getting the training wheels off?

Posted: Thu Jun 23, 2005 11:09 pm
by Neka79
maybe the calipers are sticking?? maybe the pads??
id pull the pads out, take the master cyl cap off & see how hard it is too push the calipers in...also grab sum light sandpaper & give the pads a lil clean up, and check the pads while u got em off..dunno if that will help, but cheap 7 worth a try??

Posted: Thu Jun 23, 2005 11:10 pm
by Shifty
RG, lucky you're not within arm's reach! :D

Nothing to do with training wheels though, definitely sticky brakes. Dropped in at mum's tonight, and when leaving had her push me backwards down the driveway and out onto the road!!

Neka, that's the current plan mate. Problem is that my first chance to do that is saturday morning.. and by the time I've done that most of the shops will be closed and I won't have the option of taking it to a mechanic or buying whatever parts I ned from Kawasaki or a wrecker.

Posted: Thu Jun 23, 2005 11:21 pm
by strutto
It's not the wheel bearing is it? Forks / axle bent? I guess once you pull the calipers off you'll find out pretty quickly...

Wouldn't the disks be glowing after a long ride if the brakes were jammed on?

Posted: Thu Jun 23, 2005 11:46 pm
by Shifty
They 'un jam' once you ride for a little.... for example.. if I ride around and don't use the front brake for a minute or two, and then stop purely using the rear brake, it is fine to push around. But as soon as I apply the front brake (even at a standstill) it doesn't release properly.

Posted: Fri Jun 24, 2005 12:58 am
by HemiDuty
It could be the master cyl. as well. More likely the calipers, but you never know. The piston can just start siezing if there is any rust in there, or if the fluid has gone off. Also check that the rubber boots (anywhere it has them) aren't folding over and getting in the way of moving parts.

Posted: Fri Jun 24, 2005 5:30 am
by Barrabob
some times brand new pads are like that for a couple of hundred kms the backings stick in the calipers and need a little use to free them up.

Also if he did it himself and didnt clean the pistons properly they could be sticking a bit too. :D

Posted: Fri Jun 24, 2005 9:51 am
by Glen
Does the front wheel spin freely when you've got it on the centre stand (if they have one), while you're lifting the front up.

Do what Neka said and maybe check that the dude has the right pads in it. I've had dirt bikes do this and its usually solved by a good ripping apart and cleaning of everything. Maybe also check that the reservoir is not absolutely chocka's with fluid. This could happen if the previous blokes has pushed the calipers back to get new pads in while the reservoir was already fairly full.

Be careful riding it around though, it sounds like something is definitely wrong.

Posted: Fri Jun 24, 2005 1:48 pm
by greenman43
I'd say it is one of the ports in the master cylinder blocked (probably partially) ; the system is being pressurised, and all the fluid is not being returned. Strip the cylinder, and give all the parts a good clean with metho. When you re-assemble it, use either rubber grease (preferred) or brake fluid on the seal. With any luck all it will need is a good clean, and away you go.

Alternatively, have you recently replaced the lever, or is there no free-play in the lever ? I once used a ZXR lever on an R1 master cylinder, and the levers were sufficiently different that the cylinder was always on slightly, causing drag.

Cheers,
Brian