Aug 29, 2007
10
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like it says above, my rear brake caliper is kinda loose, like i can wiggle it a good amount. when i spin the rear wheel and hit the brakes i can see it move around when i grabs. Is this normal or not, and how do i fix it....

thanks...
 

76GMC1500

Uhhh...
Oct 19, 2006
2,142
1
The pins in the caliper may be loose or the pins/caliper are worn. Some looseness is normal/acceptable, it's hard to tell you if you have a problem from here without actually feeling it myself. I would say much more than 3/32th of an inch in any direction would be too much. I don't really have any service specs. These are the 2 large caliper pins I'm talking about, not the pad retaining pin. They'll probably be around 3/8ths inch in diameter. You have to partially disassemble the caliper to get to them (remove the pads and slide if off of the mounting bracket). The manual says to lube them with Silicone grease, but I've used moly paste without problems.
 
Aug 29, 2007
10
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it appears to be loose at the axle where the whole caliper assembly attaches, Im not really sure if its suppose to be like this to allow adjustments to the chain. I know its suppose to slide on the swing arm bracket but it seems like there is ann 1/8th inch of play up and down. Also i noticed that my brake rotor is warped and is causing it to move when it hits the warped part, Probably loosened it up a little cause of that.....

there is also like a square shaped washer where the axle attaches to the swing arm that is kinda loose, like i can move it around cause the hole is oval shaped not round.....
 

IndyMX

Crash Test Dummy
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Jul 18, 2006
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Amo, IN
funkengruven99 said:
it appears to be loose at the axle where the whole caliper assembly attaches, Im not really sure if its suppose to be like this to allow adjustments to the chain. I know its suppose to slide on the swing arm bracket but it seems like there is ann 1/8th inch of play up and down. Also i noticed that my brake rotor is warped and is causing it to move when it hits the warped part, Probably loosened it up a little cause of that.....

there is also like a square shaped washer where the axle attaches to the swing arm that is kinda loose, like i can move it around cause the hole is oval shaped not round.....


So what you are saying, the rear axle is loose.

Perhaps you should tighten it.

If you have no idea about what should be tight and what shouldn't be tight, I suggest you show the bike to someone near by that knows what's what, and get it fixed.

I'd suggest also getting a service manual... :bang:
 

rmc_olderthandirt

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Apr 18, 2006
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It sounds to me like your rear wheel is messed up.

The brake caliper should be rigidly mounted and not be able to move at all. The brake pads within the caliper ride on guide pins and can be wiggled around a bit but you would have to first pry the cylinder apart and then reach in with a screw driver or something to do that. If you can just grab something with your hand and wiggle it then something is wrong.

Like Indy said, it almost sounds like your entire axle is loose. If it has been riden loose for a while and the pounding has elongated the slot that the axle slides in then you may have really mucked up the swing arm.

You should really fix that ASAP. As in, don't ride it that way any more. At best you will only cause more damage and at worst the axle can snap at a critical time and cause a major crash.

Rod
 

76GMC1500

Uhhh...
Oct 19, 2006
2,142
1
The movement you have described now is not normal and you should not ride the bike until you get it fixed you you risk doing expensive damage to your brakes, swingarm, and crankcase.
 

IndyMX

Crash Test Dummy
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Jul 18, 2006
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Amo, IN
76GMC1500 said:
The movement you have described now is not normal and you should not ride the bike until you get it fixed you you risk doing expensive damage to your brakes, swingarm, and crankcase.


Isn't that what rmc just said?
 

76GMC1500

Uhhh...
Oct 19, 2006
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I'm just emphasizing the possible damage. I had a sand whip mount break apart once which caused my axle nut to come off and I tore up all of these things.
 
Aug 29, 2007
10
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ya i dont plan on riding it this year and i am slowly fixing it up for next summer but believe me i am not riding it at all with the brakes like this....

k so my axle isnt loose at all. The wheel is spinning straight and true, so is the sprocket, however the rotor is warped.

and i did get a clymer (sp?) manual yesterday and i have just started to take the bike apart. This is the first dirt bike i have owned but i am no stranger to turning a wrench (owned 2 80's vw for 5 yrs)......


thanks for all the input. Ill go and take the caliper apart tonight, It could be just the mounting bolt is loose or something, i just havnt been home all day to look at it....
 

Yz250JdT250

Member
Apr 26, 2004
142
0
I know what your talkin about, the swingarm and that aluminum bracket are probly kinda worn out, its like that on my yz125. The rear axle goes through that bracket, so it wont move when the axle is tight. My caliper moves becuase of the pins / grommets being worn too. Maybe new grommets (the black rubber inserts) would help out..... :yeehaw:
 
Aug 29, 2007
10
0
ok so i took my rear wheel off and found out that the slider piece is not worn out, nor is the brake caliper slider piece but they are still loose. there seems to be like the caliper doesnt belong on this bike or something. Im thinking maybe a shim to put on the swing arm slider or do nothing at all.
 

rmc_olderthandirt

~SPONSOR~
Apr 18, 2006
1,533
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You really need to get a manual for your bike and see what it says.

I had the opportunity recently to inspect another bike's rear wheel caliper. I was a bit surprised at the fact that the entire caliper was "floating" on the pins/bolts that hold it to the axle/mounting plate. I am used to the brake pads floating on pins inside the caliper but not the entire caliper floating on pins.

I suspect that they do this to allow the caliper to follow a warped/bent rotor.

So, by existance proof having the caliper free to move some amount could be normal. The question is if it is normal for your bike, and if so what the limits are. I would expect a decent manual to tell you that.

If the amount of movement is excessive then I would think that the pins/bolts that the caliper ride on need to be replaced. I would not expect them to be very expensive and should be easy to change.

Get a manual.

Rod
 
Aug 29, 2007
10
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rmc_olderthandirt i have a clymer manual for my bike but it does not mention anything about the brake freeplay. ...

snb73 i think its the swing arm bracket that is worn, i could be the caliper bracket too but i can feel a little groove in the swing arm part. I most likely will get a new caliper bracket just to snug things up a bit but i am wondering if there is some sort of shim that i can stick on the swing arm bracket to make it somewhat of a tight fit (but still loose enough to adjust ) I was thinking a little strip of steel or aluminum and j&b weld it on there or something like that.

i still need to order the brake disk and my axle nut (i beat it up pretty bad trying to get it out) so i have some time to figure this out. I just dont want to have to order a new swing arm cause i might as well look for another bike if that is the case......

i will take some pictures later when i get home to show u guys the damage.....
 
Jun 28, 2006
94
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funkengruven99 said:
it appears to be loose at the axle where the whole caliper assembly attaches, Im not really sure if its suppose to be like this to allow adjustments to the chain. I know its suppose to slide on the swing arm bracket but it seems like there is ann 1/8th inch of play up and down. Also i noticed that my brake rotor is warped and is causing it to move when it hits the warped part, Probably loosened it up a little cause of that.....

there is also like a square shaped washer where the axle attaches to the swing arm that is kinda loose, like i can move it around cause the hole is oval shaped not round.....

Most brake calipers float on pins. That's why you see the caliper move when the warped rotor comes around. If the rotor is warped bad enough you will feel the brake peddle pulse. If the brake carrier is moving then the carrier could be worn where it slide on to the swing arm,axle passes through or improper assembly of the rear axle. The brake carrier should never be loose. Once the brake carrier is slid up on the swing arm the carrier will have a little free play but once the axle nut to torqued properly the carrier should not move.
 

bclark001

Member
Sep 12, 2007
230
0
if the rotor is warped it will push the caliper piston back (on a floating caliper design) causing excessive play in the caliper and as you apply the brakes every time the part of the rotor w/ the thickness variation comes around it will push the piston in more and more giving reduced brake performance and causing extended pedal travel -replace rotor-

check the rotor for lateral run out and thickness variation in at least 3 spots
 
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