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jeepwm69

Putting new seals in calipers

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So the only thing left on this 08 Foreman project is the brakes.  I have a good M/C, and bled them, but get very little stopping power.  One caliper moves a bit when I apply the brakes, the other doesn't, so I'm thinking stuck calipers.

 

Went to my pile of extra parts, pulled out a couple of calipers that also didn't seem to want to move much.  Got a grease zerk, got the old pistons and seals out, cleaned everything up, but then couldn't figure out how to get the seal back in place, along with the piston, and of course, I poked a hole in the seal while trying to do so, so will just get new seals to install.

 

Luckily upon further digging I found two good calipers so I got them cleaned up and tested, and will install them hopefully after work today.

 

I seem to recall @retro having a trick to getting the pistons and seals installed in the caliper, but don't remember where I saw it.  Anyone know the trick to getting these things in place?

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 I don't have any tricks for you , other than on other applications I have put  seals into hot water to soften them up a bit for manipulating them into position -----   I use SuperATV calipers , have never had to change a seal or experienced a stuck caliper on my atv before , LOL 

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jeep.... have any pictures we could go by ? I've delt with a few disk brakes in my time but never on an atv.... but the principal of mechanics is basically the same ... 

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32 minutes ago, Fishfiles said:

 I don't have any tricks for you , other than on other applications I have put  seals into hot water to soften them up a bit for manipulating them into position -----   I use SuperATV calipers , have never had to change a seal or experienced a stuck caliper on my atv before , LOL 

 

Fakenews.

 

@_Wilson_™beat me to it. I think they're like flat seals of some sort. I'd like to see a pic.

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Hi @jeepwm69, I have always used compressed air to reinstall caliper pistons. I wet down the bore, piston, square-cut piston seal and the dust seal with brake fluid. Then shoot a small amount of air into the brake line fitting hole while pressing the piston down (holding the piston firmly centered over the bore and dust seal the best ya can, the piston will bounce up and down and try to tilt off-center) against the dust seal outer lip until the dust seal boot expands like a balloon enough that the piston slips through the expanded seal lip. Once the piston slips through the dust seal lip you're done with the air pressure. At that point just twist and push the piston past the square-cut seal until it bottoms in the bore, then look to make sure that the dust seal lip has snapped into its groove on the outer end of the piston.

 

This method is quick and easy... but can get your fingers beat up if you feed too much air, because the piston will bounce hard against the blown up rubber dust boot and try to flip out of your fingers. I generally open the bleeder screw (or remove it in some cases) while carefully feeding the caliper a low volume of air, as it helps to minimize the violence. Hold onto the piston sides tightly .... don't get your fingers between the piston and caliper body else they'll get hammered. Sometimes just one short burst of air works the best, provided ya got firm grip on the piston. Practice makes perfect.... the second piston should go in easier than your first. :-)

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Forgot to mention.... since the outer caliper body is open in the center you can push a snug fitting plastic screwdriver handle (or whatever ya got handy that fits) into the hollow piston to use to hold the piston centered against the dust boot when ya feeding air to the cylinder. Then you won't get your fingers beat up by a bouncing piston.

 

I figured this trick out when I was a teenager working on cars. I wish I had a video of my first attempts it was a hilarious experience... The bigger the pistons are the more frustrating (and painful) it can get.

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1 hour ago, retro said:

Hi @jeepwm69, I have always used compressed air to reinstall caliper pistons. I wet down the bore, piston, square-cut piston seal and the dust seal with brake fluid. Then shoot a small amount of air into the brake line fitting hole while pressing the piston down (holding the piston firmly centered over the bore and dust seal the best ya can, the piston will bounce up and down and try to tilt off-center) against the dust seal outer lip until the dust seal boot expands like a balloon enough that the piston slips through the expanded seal lip. Once the piston slips through the dust seal lip you're done with the air pressure. At that point just twist and push the piston past the square-cut seal until it bottoms in the bore, then look to make sure that the dust seal lip has snapped into its groove on the outer end of the piston.

 

This method is quick and easy... but can get your fingers beat up if you feed too much air, because the piston will bounce hard against the blown up rubber dust boot and try to flip out of your fingers. I generally open the bleeder screw (or remove it in some cases) while carefully feeding the caliper a low volume of air, as it helps to minimize the violence. Hold onto the piston sides tightly .... don't get your fingers between the piston and caliper body else they'll get hammered. Sometimes just one short burst of air works the best, provided ya got firm grip on the piston. Practice makes perfect.... the second piston should go in easier than your first. 🙂

That was it.  Any trick to getting that dust seal into its groove?  I got one of these more or less in place yesterday, but the dust seal didn't snap into the groove, so I had to take it apart again.

 

I figured I'd need to do that, then get the piston pushed into the seal with the seal already in place.

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Got no trick for that.... unless the piston can be installed in the caliper before pressing the dust boot in place? If that isn't possible try pumping the piston out a ways then push it back down, hopefully the boot will fix itself.

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I'll give her a go when the new boots come in.  Thanks for the input guys!

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2 minutes ago, jeepwm69 said:

I'll give her a go when the new boots come in.  Thanks for the input guys!


 

if you would ditch them OEM calipers and get you some SuperATV calipers you wouldn’t be doing this. Lol.  Self inflicted pain.  

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7 minutes ago, Fishfiles said:


 

if you would ditch them OEM calipers and get you some SuperATV calipers you wouldn’t be doing this. Lol.  Self inflicted pain.  

says the guy that has to replace super atv brake pads after every ride ?!..rofl.

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wow! this is turning to be just like a tire thread .... i may have to back away ... lol ...

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4 minutes ago, _Wilson_™ said:

wow! this is turning to be just like a tire thread .... i may have to back away ... lol ...

No.  Just you turning it into something it ain’t again. 

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10 minutes ago, shadetree said:

says the guy that has to replace super atv brake pads after every ride ?!..rofl.

You know I get 3 rides. 

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huh ? i didn't try to change the subject... i was making a joke ... lol. you know ... defrent thoughts on aftermarket disk brakes ??

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2 hours ago, Fishfiles said:

You know I get 3 rides. 

you must be near FL ?, cuz ya know...they can't count down yunder !..rofl.

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13 minutes ago, shadetree said:

you must be near FL ?, cuz ya know...they can't count down yunder !..rofl.

1 + 1 ain't 3 up dare in Little Rock ! 

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Just now, Fishfiles said:

1 + 1 ain't 3 up dare in Little Rock ! 

ya sure ??..lol.

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Posted (edited)

 

16 hours ago, Fishfiles said:

 I don't have any tricks for you , other than on other applications I have put  seals into hot water to soften them up a bit for manipulating them into position -----   I use SuperATV calipers , have never had to change a seal or experienced a stuck caliper on my atv before , LOL 

 

thats kind of what happens when you have to change pads all the time ... lol 

Edited by _Wilson_™

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