Seized Brake Caliper?

LoneRonin

LoneRonin

Well-known member
I had put on new pads and rotor and the rear wheel was tight at first, I thought it was because of the fresh pads and aftermarket rotor being a tiny bit thicker.

It would spin by hand but not freely, over time I thought it would improve with use and wear but it really didn't. I was given the suggestion to push back the pads a little with a flat head and it worked, but now I noticed there is plenty of space in there for the pads and rotors.

Its only when I apply the rear brake hard (by hand) that it gets tight again. I'm spinning the wheel by hand on the rear stand and it seems as if its got that drag again but the wheel WILL still spin, just not as easily.

SO, is this case of the caliper being seized? It feels as if it doesn't want to let off the pressure fully. Is this just a simple case of taking it off and cleaning the pistons? Its one thing I've overlooked because I haven't touched my rear brake in ages, bike is a 09 Ninja 250 with 70k km...
 
LoneRonin said:
I had put on new pads and rotor and the rear wheel was tight at first, I thought it was because of the fresh pads and aftermarket rotor being a tiny bit thicker.

It would spin by hand but not freely, over time I thought it would improve with use and wear but it really didn't. I was given the suggestion to push back the pads a little with a flat head and it worked, but now I noticed there is plenty of space in there for the pads and rotors.

Its only when I apply the rear brake hard (by hand) that it gets tight again. I'm spinning the wheel by hand on the rear stand and it seems as if its got that drag again but the wheel WILL still spin, just not as easily.

SO, is this case of the caliper being seized? It feels as if it doesn't want to let off the pressure fully. Is this just a simple case of taking it off and cleaning the pistons? Its one thing I've overlooked because I haven't touched my rear brake in ages, bike is a 09 Ninja 250 with 70k km...
Click to expand...

No one can tell you that from the comfort of their computer and not seeing it in person.

Id clean it first and try to move it back and forth a couple times to see if it gets better...
 
There is no real good mechanism on those rear brakes to pull the pads apart, the pads will always drag aganist the rotor.

If it isn't an OEM rotor and is thicker - that might not give the pads enough room to drag gently against the rotor.

If you are going to go the trouble of blowing the pistons out and cleaning it, you might as well put in new seals, it should be around $20-$45 for a seal kit for a caliper. And I think the rear on that bike is a single piston...so it should be ultra cheap.

If the rear brakes are binding/getting tight? is it the whole way around? or is it tigher in sections?
 
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The ninja 250s have two pistons for the rear caliper but they are on the same side... kind of a weird design.

If you take the pads out and push both pitons in and then push the brake pedal you should see both pisotns moving at roughly the same rate. If one comes out much further than the other, the one that isn't moving much is binding. The only effective cure for binding pistons is a caliper rebuild. Ninja 250 caliper rebuilds are as simple as you can get.
 
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