Question on Calipers
11-03-2010, 12:59 PM
#1
Racer
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Question on Calipers
Is it necessary to split the calipers for an O-Ring conversion?
Stupidly I'm after taking off the calipers painting them without reading bout caliper rebuilding.
Is the small seal between very important to change?
Stupidly I'm after taking off the calipers painting them without reading bout caliper rebuilding.
Is the small seal between very important to change?
11-03-2010, 01:21 PM
#2
Race Director
11-03-2010, 01:45 PM
#3
Team Owner
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....and
11-03-2010, 11:23 PM
#4
Here are my stainless steel sleeved calipers that I recently rebuilt.
Split halves. Remove dust seals and pistons.
Wear mark left by lip seal after 25 yrs. of service.
Caliper halves after cleaning with wire brush wheel on bench grinder and final cleaning with laquer thinner. Before and after.
Cleaning bores with very fine scotchbrite pad and brake fluid as a lubricant
Bore after scotch brite. Wear mark was just on surface as SS did not pit over the years.
Use old dust seals and paper towel to mask off bores. Note that caliper half mating surfaces have been sanded flat using sand paper mounted to a thick piece of glass for a flat surface.
Painted caliper and parts to rebuild front caliper. Rear calipers use one o-ring to seal halves.
Piston with o-ring and dust seal. Some say do not use spring with o-ring pistons but I did anyway. Use brake fluid as a lube before placing pistons into bores. Press pistons into bores by hand.
Rear dust seals are easy to tap into place but fronts, being larger, are more easily bent while installing. I bent the first one but was able to straighten it out. I tapped in one side then worked opposite side of seal into bore and finally got it in straight. Place small o-rings in their recesses while holding up opposite half with bolts started then slide halves together and tighten bolts.
Finished caliper ready to install.
Other Members, feel free to correct or add any info. Good Luck with it. mike...
Split halves. Remove dust seals and pistons.
Wear mark left by lip seal after 25 yrs. of service.
Caliper halves after cleaning with wire brush wheel on bench grinder and final cleaning with laquer thinner. Before and after.
Cleaning bores with very fine scotchbrite pad and brake fluid as a lubricant
Bore after scotch brite. Wear mark was just on surface as SS did not pit over the years.
Use old dust seals and paper towel to mask off bores. Note that caliper half mating surfaces have been sanded flat using sand paper mounted to a thick piece of glass for a flat surface.
Painted caliper and parts to rebuild front caliper. Rear calipers use one o-ring to seal halves.
Piston with o-ring and dust seal. Some say do not use spring with o-ring pistons but I did anyway. Use brake fluid as a lube before placing pistons into bores. Press pistons into bores by hand.
Rear dust seals are easy to tap into place but fronts, being larger, are more easily bent while installing. I bent the first one but was able to straighten it out. I tapped in one side then worked opposite side of seal into bore and finally got it in straight. Place small o-rings in their recesses while holding up opposite half with bolts started then slide halves together and tighten bolts.
Finished caliper ready to install.
Other Members, feel free to correct or add any info. Good Luck with it. mike...
Last edited by mds3013; 11-03-2010 at 11:35 PM.
11-01-2011, 06:35 PM
#11
Pro
Just wondering how the brakes are holding up after all your work to bring them back to life!? How the heck did you get the calipers so clean? You said wire brush and wheel but really?? Nice work, making me consider doing mine instead of buying new. 
11-01-2011, 08:08 PM
#12
They are doing well. They were bought in '82 from a local Corvette supplier. Car is always garage kept. I cleaned them with a 6" wire wheel on a bench grinder and about 15min. each half, then the lacquer thinner. I use Dot5 fluid so there was no need for "caliper" paint. I primed them with Rustoleum engine primer and high heat red. One can primer, two red. mike...
11-01-2011, 10:37 PM
#13
Safety Car
Beautiful. Great write up
11-04-2013, 08:41 PM
#15
Race Director
since the original caliper has lip seals and is rigid mounted is it better to use the OE style lip rather using a floating caliper style say maybe like the 84`s with there non floating O ring seal?
11-05-2013, 06:55 PM
#16
Safety Car
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The rigid caliper grips the rotor from both sides while the floating caliper relies on the castings being clean enough to slide smoothly every time the brakes are applied. I've rebuilt enough daily driver calipers to know that this design is intended to save $ more than to enhance braking capabilities.
If you rebuild a ss-sleeved C3 caliper with O-ring seals you have the advantages of the rigid caliper and the ability to store the car without worrying about the brakes leaking. I rebuilt my calipers with O-rings in 2009 and the car gets driven a lot less than it should. I have not had any problems with leaks. My previous lip seal rebuild failed after sitting on the shelf for a couple of years while the car was rebuilt.
Rick B.
11-05-2013, 07:40 PM
#17
I found it's easier getting the dust boots in by C-clamping one side of the ring, putting the caliper in a large shop vice, and carefully tapping the opposite side of the clamp first.
I wish I'd seen your excellent write-up before starting on my calipers. Several great tips. I was struggling to install those pistons using a piece of plastic strapping. A jeweler's screwdriver would've saved me a LOT of time.
Dan G>
Last edited by Capkunu; 11-05-2013 at 08:03 PM.
11-05-2013, 11:38 PM
#19
Safety Car
The work looks intimidating, but its really pretty easy. When putting the new dust seals in place you need to take your time, and use a little bit of brake fluid to get them to seal, using the fluid as a lubricant to get the rubber in place.
kdf
kdf
02-03-2014, 07:05 PM
#20
One more thing. The torque spec on the bolts holding the front caliper halves together is somehing like 120 ft/lbs. It might be easier to break them a half turn loose while the calipers are still bolted to the spindle.