Brake problem, 90KDX 200

[adckdx]

I have a 90 KDX 200, recently replaced the rear pads and disc. The pads were picked up from a buddy who got rid of his bike (same bike as mine). They have never been used, but not in the new package, just sitting in the garage for the past few years.
Can brake pads dry rot or become useless after sitting for a long period of time?? The brand is the same one I always use so I know it is not a quality issue. I've changed brake fluid, bled and bled and bled the brakes to no avail. The brakes lock up if pressed hard enough, but other than that I get nada.
Went for a ride today, took a look at the brakes when I got home and they are worn down pretty good already.

Any ideas??

 

[CaptainObvious]

What is the condition of your pins? Did you use never seize on the surface? Does the piston move without binding? If the rubber seal is twisted the brakes will not work correctly. Do you see any fluid by the caliper piston?

 

[David Trustrum]

Yeah sounds like they are seizing. Time for a caliper strip I think. Check the pins as said above (remove pads & slide caliper off mounting plate - use hi temp copper grease) & that the wheel spins ok(ish) & that the master cylinder is allowing to return (freeplay in lever) & breather in lid ok.

Pump the piston out as much as you can with the pads removed & pull the piston out. There may well be gunk behind the piston preventing it returning properly. Clean the piston up & have a look at the seals if they need to be replaced do so. Be clean in there & put it back together.

 

[adckdx]

I did'nt use never seize this time around. Everything appears to be pretty clean, pins look good, no fluid where there should'nt be. I'll break it down in the next day or so, do a closer inspection of the piston and let you know what I find.

Thanks.

 

[jamin326]

i have a rear brake caliper, actually whole assembly off of a 91 kdx200 email me if interested, say $30

 

[adckdx]

Took a look today, pads are completly worn after only 3-4 rides. Pins are smooth, no groves. Took piston out, very clean. Re-drained brake fluid, might have been some water in there, not sure. Waiting on new pads from D.K., will just have to wait and see how they do. Thanks for the replies.

Jamin326 - thanks for the offer, bought a rear brake assembly off of e-bay a couple of months ago just for extra parts. You are about $20 cheaper though.

ADCKDX