96GS#007

Anyone have a rule of thumb or indicators they look for regarding when it's time to replace brake calipers? The calipers on my GS are original and have seen many thousands of track miles.

Nothing is currently wrong with them...ie the pads don't taper, braking is fine, no apparent defects, etc. However, I'd rather error on the side of caution versus finding myself sailing thru the trees and thinking "damn, should have replaced those calipers...."

Thanks,

Sidney004

Yeah they are junk, just send them to me; I will pay for shipping.
The failure mode on these calipers are when they spread. So long as you are not experiencing radial pad taper, they are fine IMO. However, my offer still stands.

SouthernSon

Well, you are on the right track by stating no pad taper yet. Keep the calipers but you might consider replacing the pistons with stainless steel if you are concerned with heat at the track. Of course, Mid America has a retrofit front spoiler with cutouts for brake ducts, too.

Kanmer

Jim, you actually use your brakes?

Bob

davidfarmer

It's been a while since I've done anything with C4 brakes, but on the C5, I can "spread" a front caliper in half a season of hard use. The backbone of those OEM calipers is very weak, and heat and fatigue stretch them out rather quickly, although they work very well up to that point.

If you look at a Monoblock caliper (like Brembo, Stoptech), you see that they backbone of the caliper is extremely beefy, and this allows them to hold up year after year.

96GS#007

I have plenty of cool air via my brake cooling setup

My concern really centers around caliper fatigue. Specifically at what point do the stock calipers simply decide they've had enough of life and spread apart or crack? Seems like pad taper is what I should use as a warning sign.

96GS#007

Only after I see God and count to 3

mlfair43

What does it mean when you get radial taper on the pads, but it's opposite - one pad is thinner at the top, and the opposite pad is thinner at the bottom. Is this spread, something else going on, or normal for a C5 with OEM calipers? It would appear that the caliper is cocking, but not spreading. However, I've been having problems with a soft pedal that pumps up, and I'm not sure where else to look. I have braided lines, and I just replaced the front hubs, because I heard that was something that could cause this, but frankly, the old ones seemed fine. The car is a 99, but I bought it with 20K street miles on it 5 years ago, and it has 17 track days totalling about 2000 miles of track time.

longdaddy

we have a thread just for you

http://forums.corvetteforum.com/auto...-opinions.html

short version: you can try replacing/re-lubing guide pins and flipping pads around, as well as "pre-pumping" the pedal but this is normal and you will have to continue to have to deal with it unless you have $$ to sink into properly designed calipers

Sidney004

Radial pad taper due to spreading(which is measurable on the caliper) will result in both pads being thinner on the top and thicker on the bottom. Your soft pedal is probably a result of whatever is causing this unusual wear pattern. Is it on only one caliper? If so, cheapest solution is change the caliper with new hardware.

mlfair43

I failed to update this last year, but did mention the resolution in another thread. My hubs were the original ones, and though there was nothing obviously wrong (no side play when rocking the wheel, nothing with rolling resistance or noise, etc.), I replaced them, and it solved the long brake pedal issue. Apparently, the hubs can have play in them under real suspension loads, but not enough that you can find problem by rocking a wheel. I'm sure they would have developed a more severe failure over time, but the long pedal (one that pumps up due to pad kickback) is apparently a good early warning that the hubs are worn.

kmagvette

How old are your wheel bearings and how hard are you tracking the car? Got sticky rubber too? Old, Hard, and Sticky () will give you the soft pedal and the pad wear mentioned above. The pad taper (along the length of the pad) you are seeing is from the normal flexing of the brake system. This condition is exacerbated by worn out bearings. Worn out bearings will also allow more knock back thus giving the soft pedal.

Most of us that flog the car hard have gone to the SKF X-Tracker bearings sold by various vendors on this forum. They are a great upgrade, but do not totally eliminate knock back. I still double tap, but way lighter than I used to with stock bearings.

Zenak

Radial wear = caliper spred. VERY common on crappy C5 calipers. Get C6 calipers to replace them for the OEM stock C6 set up. Same exact size as the C5, but jsut a better bracing in the rear.

If you get an SKF hub get the ARP studs so if you need a spacer later with a BBK on your current rims the longer studs make this easier.

Not all braided lines are teh same. I went to the goodridge form DRM and its so much better than my old ones I got from another vendor. Also the DRM pistons for thermal transfer for the C5, and the quantum duct kits and heat shields.

If you let the pads get too thin the pistons push out and then you got issues. You get piston wobble. Im designing a shim to fix this currently. Almost done.

See this thread for 99% of these questions answered, its a sticky in this section. Why doesnt anyone read stickies :-P

http://forums.corvetteforum.com/auto...e-learned.html