NewFoundPower

I've been considering rebuilding mine but wanted to see how I can tell if they need it or not. There are no leaks from around the pistons, the rear dust boots are torn a bit but the fronts look ok. Is it a good idea to rebuild them "just because" after a little over a year and a half tracking the car, or should I wait? I don't need to go looking for things to spend money on but don't want to have any problems come up that could have been avoided by rebuilding.

0Anthony @ LGMotorsports

You should have a mileage that you go by, but this typically only comes by either the manufacturer, or a log of how long you have seen them last.

Of course the dust boots go away the first day, but keep an eye around the piston seals. If you start to see a sweat (not leak) but a sweat around the pistons then they should be torn apart and cleaned. Everytime they come apart they need new seals. Check the pistons for roundness, any scarring, or chips. Any big marks on them that can not be easily removed with some very fine paper, the pistons should be replaced.

Completely depends the brake, the tracks, the pads, and the driver on when they should be done.

Also if it is a caliper that has cross over lines, you need to inspect them as well for cracks or leaking as vibrations will wear these out over time.

wtknght1

For stock calipers, rebuild them only if it's leaking. If it's not, then pound on 'em til either they leak or spread enough to get that funky pad taper (top to bottom). When that happens, throw them away and buy another caliper...don't rebuild it.

dbirdz06

davidfarmer

If you EVER have to rebuild a stock C5/C6 caliper, then it's likely deformed beyond repair. The seals outlast the caliper by a long shot when used for track duty.

For a racing caliper, I wouldn't rebuild them unless they start weaping fluid. I had this happen in one hard racing season on calipers that didn't have titanium/SS caps/shields. Your mileage may vary.

0Louis @ LG Motorsports

You guys kill me. Hey, lets wait till they leak to replace them!!! Uhhh, what happens when you drive the car to the track, and they start leaking AT the event?

How about when the start to leak on track?

TIME them out!! You must WORK on your car people, you cant just run it into the ground and expect it to last forever, and you never get hurt!

Pull the caliper off, inspect it. Replace the seals and see how bad the old ones are. If they are still good, go one more track event, and then pull them apart again.

Your mileage may vary, WC cars go 3 races. GT2 car goes 30 hours of track time. Lous street car went 1 day at the track

Louis

jaa1992

On my C4 - 10 - 15 events for the fronts, depends on where I go and what they look like. I bleed until I get fresh fluid after each even though. I haven't had to do the rears yet.

I usually get a reman set from Autozone or wherever, less hassle than doing it myself and don't have to worry about spread. Dust boots are usually gone after 1 or 2 events though.

NewFoundPower

Thanks for the responses guys!

I forgot to mention they're stock calipers, and I don't plan to upgrade them for the forseeable future (will replace if necessary) so I can stay in my NASA class. I have no points to spare!

I am currently using Carbotech XP12 front and XP10 rear pads. I didn't have any taper on my last set, but in the front the outside pad was worn noticeably more than the inside pad. I expected it to be the other way around. What does that mean?

Also, on one set of pads I was using this past summer (XP10/8) I did have significant pad taper on the fronts. It only happened on one set of XP10s, hasn't come back since I switched to the XP12s. I am significantly harder on the brakes now (fronts will last about one weekend - thanks for the motivation Chris!) but I don't know if that would explain the taper going away. Any thoughts?

I do have about 15 track events on them, but that covers back to when I just started going to the track so it's not 15 all-out events. Sounds like I don't need to worry about it yet with stock calipers, but it wouldn't be a bad idea to have an extra set... Is that a fair assessment?

wtknght1

The XP12s are just a superb pad for the front especially when you start really pounding on the brakes hard. They cure most tapering issues. Carbotech is also working on some new development stuff that I'll hopefully get a chance to test out while I'm down at the Florida Nationals. Danny had a big grin on his face when we talked down in Atlanta, so I know it's REALLY impressive. I hope I didn't let some secret cat out of the bag.

If you're using the stock C5 caliper, you'll eventually get to the point where you need to replace them about every 3-5 events to be honest. They'll just start to spread on you. The C6 calipers have a thicker outer wall and don't suffer the spreading issues nearly as bad. But for the C5 caliper, just replace them once a year (they're cheap) and keep the old ones as a spare just in case. I've never seen one leak. As Dave said, they'll spread long before the seals fail.

dbirdz06

Are there any measurements you can take of the caliper to see if they are within spec or not?

Bill Dearborn

Chris,
If I threw away the stock calipers on my 97 and 03 the first time pad taper showed up I would have been replacing them when they were brand new. The pads on my 97 tapered by the 2nd session of its very first track day w 2700 miles on the car.

Bill

wtknght1

None that I know of...because the measurements aren't the same when the caliper is cool vs. when it's smokin' hot on track. It's easy to tell though if they are toast - if the top of the pad is thin, but the bottom is really thick, then your caliper has spread and needs replacing.

...or if you're getting excess taper on either the leading or trailing edge.

And yeah, 2-piston squeezer calipers may normally show a bit of taper even when they are new, but if you're really trying to get the last .1 or .2 out of a lap, everything counts. When I ran my C5, I replaced my front calipers once during the middle of the season and again at the runoffs (about every 5 events).

Jason

Damn, my pads are always tapered to hell.

jackcasual

I've got an 04 ZO6 and run several events every year. I have run some events @ Road America. My best lap time there is 2:29. The last thing I want is to not have brakes going into turns 1,5 or Canada Corner or I guess any corner @ any track. I have front calipers on the rear also. I rebuild all 4 calipers every winter. It gives me a chance to look at everything and no I don't have any issues. Got to agree with Louis.

Webz

For stock calipers, it's like $15 per caliper for the repair kit and maybe 1/2 hour of time per caliper (if done during a rotor change). I rebuild mine once per season. Definite peace of mind if nothing else.

dbirdz06

$22.95 & $22.97 to be exact

AutobahnCCZ06

how did you mount the front calipers on the back? did they just bolt right up with new front rotors back there too?

Sidney004

I measure the parallelism between the piston mounting faces and the opposite "clamp" If they are skewed more than .030; they are really garbage because they are plasticaly deformed and weakened and will go downhill fast. This is based on my observation on J55's.

jackcasual

Yes, it all bolts on

AU N EGL

for stock calipers, if you do lots of events, toss them each winter.