Help Please

[mooseracerX]

I've been having this problem for sometime now. My caliper keeps sticking. I take it apart ground down some of the pad and put it back on a few times, but its either a bent pin that holds the pads or the complete caliper is screwed up. The piston pushes against the pad but the pad doesn't push back and it drags horribly on the rotor. Its really annoying and kind of dangerous while MX racing landing with the brake on so to say. Has anyone had this problem or herd of a solution to this problem? Does anyone have a stock caliper laying around that works and might want to get rid of? I'm going to look on OEM for the pins and hope it is that but I'm hoping one of you guys could help me out.
Thank you very much
Moose racer 416 ex. =\

[mooseracerX]

Alright I just go back in from trying something. I put a worn out pad on the inside and and put it back together. It is the piston that isn't working. I pump it and the piston goes out but it doesn't go back in. Does anyone know what I could do to fix that? could I WD the piston? Do you think that would fix the problem or am I better off getting a caliper rebuild kit?

[Pappy]

I would suggest taking the sliders out, cleaning and lubing them. rarely do calipers go bad.

http://www.exriders.com/vbb/showthread.php?s=&threadid=348212

The piston will not snap back in after you stop pumping

[mooseracerX]

Are those the two pins that hold the pads in?

[Pappy]

thats correct


and some cheaper pads will be thicker then the stock units, not sure why but they never seem to work as well or even last as long, but we usually replace them on machines with braking issues first and foremost. ebc and oem is all we use here.

[mooseracerX]

Alright I just got done cleaning them up. I use streamline myself. They are thicker put that doesn't explain why one side works great and the other doesn't. I'm going to try them out right now. Do you think making the holes on the pads a little bit bigger would do anything or make it worse?

[Pappy]

no, the holes wont do anything


is it possible you may have a bent rotor on the side giving you problems?

[mooseracerX]

Yeah I realized that the holes wouldn't do anything because the pins slide in and out fine. Its got to be a bent rotor. When I bought it used it had an OEM on one side and a Moose Racing on the other. I was trying to save money and bought a used rotor and its got to warped. Plus it was off a 300ex or something and it has a size of 3.0mm on there and the other one is like 2.5mm. You wouldn't happen to have a new rotor would ya? haha I'm looking on OEM right now, they want $150 for one disk WTF?!? You can get 2 Streamline waves for that.
I'm going to try the Moose racing tomorrow since it is getting dark. If that is the problem I'm going to get a brand new OEM one to match.

[mooseracerX]

Alright its not the rotor. It wasn't as dark as I thought it was. It made it worse if anything. I'm a little P.Oed right now because instead of practicing this weekend I have to my dad work on taking the dang caliper apart and figure out what the problem is. Just to give you a picture of how bad its dragging w/o the wheel on you can hardly turn the hub. There has to be crap inside of the caliper causing it not to release. Its the only think I can think of at this time. I bet the 1st thing my dad will say is why didn't you leave it alone it was fine to begin with. haha THIS SUCKS to the 3rd degree.

[BigBore24]

i had the same problem. turned out a previous owner left the rubber plugs off for the slide pins and they got water in there and the pins siezed up. ended up ruining the calipers trying to get them freed up

[buster024]

This seems to be a fairly common 400 problem. Same thing happened to me, and we're going through it right now with my riding buddy on his. Sand and saltwater probably jammed mine up, although I'm not sure what's up with his.

So not to hijack this thread, but it's along the same topic. I just rebuilt my back end, including running new rear brakes. I bled my brakes, and I can see the piston move, but it won't release back without help. I can push it back with a screwdriver using very little effort, but it won't come back on it's own. Lube problem?

[mooseracerX]

^^^ Yeah same with me I can push it back but it won't release. Its not the pins. I has to be something with the piston. I'm thinking he hit something or flipped it hard on that side and that is why that side had a different rotor on it. I guess I'll just have my dad cuss and swear at it and take it apart. :mad: :ermm:

[madmax400ex]

Like Pappy said pistons don't spring back in. When you release your brake lever the pressure releases on the piston, which will allow the pads it to free up against the rotor, but the piston will always be touching the pads. So if your piston is getting stuck when you release the brake
then something is causing the pressure on the piston or the pistons is locking up when pressure is released. I would do a rebuild on the caliper. When you take out the piston take a good look at how the piston slides back and forth in the caliper. I am not sure what the problem is, this is very weird.

[madmax400ex]

Does this happen right from the get go or does it take awhile like when the brakes are warmed up?

[mooseracerX]

Nope right away. As soon as you put the brake back on the rotor and pump the brakes a few times it doesn't release all the way and drags too hard to turn.

[madmax400ex]

Definitley a caliper issue - Try a rebuild or just buy a new one, cause i am not sure if a rebuild will solve the problem!

[mooseracerX]

Like I said I'm going to have it taken apart, maybe it is just some junk on the piston, hopefully that is all it is. Unless I could find a used caliper that works it would be super expensive. OEM wanted 150.00 for a single brake pad WTF. haha

[mooseracerX]

Alright we need either a new caliper or the two pins that it slides on. They have to be bent. My dad took out the piston, cleaned it greased it, and put it back in. That isn't the problem. The problem is that it doesn't release after getting pumped up. If we loosened up the pins it got a little better but we know it is the pins fault.

[mooseracerX]

Alright my dad found the problem. The plate that holds the pins and holds the caliper to the spindle was bent. Tell me how that happens?! The pins were like this V in stead of being like l l. He heated the plate up and straightened it out so now they work better, still not as good as the other side but just about.

[madmax400ex]

Glade to see you guys figured out the problem. So at least it won't be to expensive to fix. Definitley a weird place for the brakes to be bent.