Warning on C4 Calipers

[jannes_z-28]

I did some work on my car and it involved removing the front calipers. I couldn't believe what I saw. They were bent! Apparently they are to weak for highpressure systems like my HydraBoost combined with a S-10 M/C.

I haven't noticed any problems with the brakes, up until now they have worked. I have to admit that they have got a fair share of abuse.:evil:

Look at the picture to see tha angle they now have. I didn't see any cracks or so. They would have held up a while longer.

I will now change to C5 Calipers which are much stronger.


http://www.protouring.se/files/bent_c4_caliper.jpg

Jan

[Fluid Power]

Holy bent caliper Batman!

Yikes!

Darren

[Stielow]

On C-5 Corvette race cars the calipers are a consumable item. We replace them after a set period of time. The elevated temps from track use weaken the bridge of the caliper. This also leades to taper wear on the brake pads and a long brake pedal.

Mark

[Apogee]

There are also two C4 calipers, the early gravity cast version and the 1996 Grand Sport pressure-cast version. While neither is exactly robust by today's standards, the Grand Sport calipers do tend to hold up a little better in severe-duty use.

To add to what Mark said, the C6 calipers have additional material across the bridge to make it stiffer and give it a longer service life, so I would suggest you consider those over the C5 calipers if that's the direction you decide to go.

Another thing to consider would be the amount of pressure your system is capable of generating at the wheels...hydro with an S10 MC sounds a bit overkill. Best case is that you are using the late-model disc/disc unit with a 1" bore. Worst case would be that you're using the early S10 quick take-up MC with a 15/16" [24mm] secondary bore. Have you installed a pressure gauge at the caliper to see what you're getting there? Most people run a 1-1/8" bore MC with hydro and C4/C5/C6 brakes.

Either way, any pressure generated beyond lockup is only shortening your caliper life for no additional gain in performance, just a decrease in pedal effort. There have been several threads lately about the 1-1/8" bore MC's feeling touchy on GM hydro units...how's the feel and modulation of your setup?

Tobin
KORE3