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Old 12-30-2010, 06:46 PM   #1
Dookie
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Default Brake Caliper Rebuild - Walkthru

After several months of figuring out my heavy vibrations under braking, found out I had a frozen piston on my driverside caliper. Here is my walkthru to rebuilding the caliper.

1. Disconnect the brake line from the back, twist a shop towel through the banjo (to prevent leaking) and tie it up out of the way.
2. Unbolt the 2 slider bolts and pull the caliper off.

Pic of caliper


3. Use an air compressor to push the pistons out, make sure to place a few pieces of wood to catch the piston and not damage them. Takes about 40 - 60 psi from the compressor.





4. Pull the pistons out and carefully remove the inner seal, try not to scratch the inner walls.



Pics of the new seals and boot covers with the old pistons.



5. Clean and wash the caliper in soap and water, do not use any degreasers. Use a 2000 grit wet sandpaper to remove any burnt or ruff areas inside the caliper if needed.



6. Dry and air blast any remaining water or dust.
7. Place the new inner seal in place and grease (piston grease) or oil (brake 0il) to the inner cylinder, seal and piston.

Last edited by Dookie; 12-31-2010 at 12:28 PM.
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Old 12-30-2010, 06:50 PM   #2
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8. Place the boot cover on the very end of the piston, the end that goes into the cylinder. Make sure you have it on correctly before placing it into the cylinder. I recommend practice placing the boot into the cylinder before connecting the piston onto it.






9. Slide the piston in while holding the top of the boot. The boot will connect to the pistons ring once the piston is pushed half way in.



10. Push the piston all the way in using your hand, making sure it goes in straight.


11. Reinstall caliper in reverse order.
12. Bleed the brake line and you're all done.


Enjoy your new regained stopping power.

Last edited by Dookie; 12-31-2010 at 12:28 PM.
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Old 12-31-2010, 09:27 AM   #3
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Great walk-through!!!! Thanks!!
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Old 12-31-2010, 03:00 PM   #4
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Agreed - great walk thru. I'd intended to do something like this when I rebuilt mine, but was too lazy. Thanks Dookie!
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Old 01-03-2011, 04:10 PM   #5
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Thanks guys. Still was having some vibrations and decided to pull the otherside off. Yup, same issue, a frozen piston. After rebuilding both of them now, the vibration has ended. Whoot!


Recommendation - Do both at the same time, to save time.
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Old 01-03-2011, 04:47 PM   #6
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ew...I hope mine don't have problems. Good walkthrough, thx!
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Old 03-16-2011, 07:29 AM   #7
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Quote:
Originally Posted by Dookie
After several months of figuring out my heavy vibrations under braking, found out I had a frozen piston on my driverside caliper.
I am having the same vibration problem. How did you fig out it was a frozen caliper piston and where did you get the rebuild Kit??

Last edited by JonboyGT; 03-16-2011 at 08:43 AM.
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Old 03-16-2011, 09:14 AM   #8
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How to test your calipers:

1. Unbolt the 2 slider pin bolts on the back of the brakes.
2. Pull calipers off and rest them upside down on top of the rotor.
3. Have a friend slowly start pumping the brake petal.
4. Watch the pistions as they go out/in, one maybe slower than the other which is normal. If you notice one of your pistions is moving very little or not at all, then you have a sticky/frozen pistion.

One of my dust cover boots was torn and dust/dirt got in causing the pistion to freeze.


Keep in mind, there could be several reasons for braking vibrations. Such as:
1. Glazed/warp rotors - needs to be turned or replaced
2. Uneven pads - Check the slider pins, relube.
3. Worn/torn LCA bushings - replace
4. Rear brakes will also cause the same issue, so make sure to check them too.
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Old 03-16-2011, 09:40 AM   #9
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Thats kinda how i thought to check them. Thanks. I was planning on checking all of the above as well just wasnt sure on the pistons. So best place to find a rebuild kit would beeeee. . . . . ??
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Old 03-16-2011, 01:01 PM   #10
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Oh ya, I bought my kit from the dealership for around $18 bucks. It includes 4 seals, 4 boot covers & 4 guide/slide pin boots (covers both front calipers).

Or you can get them hear for a little cheaper.
http://www.rockauto.com/catalog/raframecatalog.php
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Old 03-16-2011, 01:22 PM   #11
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Nice. That site is sweet. Thanks.
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Old 03-27-2011, 07:14 PM   #12
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Nice walkthrough!

What do you do if only one of the pistons comes out when you are applying the compressed air? This happened on both front calipers with mine. It seems one is more prone to freezing up than the other. I have them soaking in PB blaster, but with one already removed compressed air is out of the question. What would you do?

I am hoping the answer is not "buy new calipers".

...but I am thinking it may be....

Thanks,
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Old 03-28-2011, 09:34 AM   #13
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MDD - About the only other way to pop the other piston out is to secure the good piston in place. Put the good piston back into the caliper, place a block of wood between the good piston and the caliper to lock it in position. Now pump up the air to over 60 psi or more and try to blast out the frozen pistion.

This should work as long as the other pistion is lock into place forcing all the psi to the other pistion.

If not, time to buy a new caliper.
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Old 04-05-2011, 05:45 AM   #14
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Default Good tip!

Thanks for the idea Dookie. It worked like a charm for removing the other piston. I have them all apart, and they are being powder coated. I am hoping the rebuild will be as easy as you made it look.

Regards,
Matt.
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Old 04-05-2011, 10:41 AM   #15
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I'm glad it worked out for you.

How do the pistons look? Are there any deep scratches on them? If they look good, just make sure to practice placing the boot cover in the housing 1st then the rest is pretty easy.
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Old 04-05-2011, 11:31 AM   #16
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They look good. There were no significant scratches. There was also no staining on the inside of the caliper. Except for the corossion around the top of the piston, they looked pretty good. Even that was pretty easy to wipe off. I did spray them with PB blaster several times and let them soak for a couple days, so that may have helped. I had time to wait as I am doing the suspension at the same time.

One interesting thing to note is that my pistons were sized to fit the specific caliper they came from. I accidentally grabbed the piston from the other caliper and it would not go back into the caliper I was working on at the time. It was not a huge size difference, but it was easier to push in the one that came out of that caliper. So, the moral of the story is, if you are rebuilding both at the same time, remeber which pistons came from which caliper.

I get to try rebuilding the rears also. That one looks a little more diffucult as there is a retaining ring that holds the boot in place. I don't see how you can place the ring with the piston already in the boot. I figure I'll try the fronts first, and then tackle the rears. The rears were in good shape and not frozen, but the powdercoating process made it necessay to take them apart.

Thanks again,
Matt.
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