KoreaJon

Yep, that was pointed out in one of the threads I read. I ordered new pads for the fronts brakes, and plan to clean the brake pad material from old front brake pads...then weld the (cleaned) backing pads onto the back of the new (rear) pads. This would make the new rear pads sit deeper in the caliper bracket.


Thanks for the clarification!


Regards,
KoreaJon

Cutlassmaster

Multiple vendors on here will sell you the metal plate instead of having to clean the pad material off of the metal. Probably quicker and safer than ckeaning it off and possibly breathing residue of the pad.
Chris

Caveboy

Are you using the brake caliper brackets from C5 Z51 or C6 Z51?

lionelhutz

C5 front calipers and C5 front brackets. They are all the same.

Caveboy

Who are some of the vendors that sell the backing plates. I would love to buy them instead of welding

BABYBUGY

good work
thank you for the write up

KoreaJon

I'd love to have gotten some, as well! But either way, the new backing pads will NEED to be welded to the existing brake (backing plates) pads....it's pretty simple, though...I have a TIG welder, probably won't take more than a couple of minutes per pad.



My pleasure!


Regards,
KoreaJon

romandian

so what bout brake balance. how does piston area compare to stock? are you saying you have more braking force in the rear now without the abs comming in early? shorter stopping distance?

KoreaJon

The balance actually feels better now....there is far less front-end dive when using the brakes at their limit.

Piston area? I don't know. If you look at the size of one of the (single piston) rear calipers you can see that the area is far smaller than the (twin piston) front calipers. I think that equally indicative of the increased braking force is the area of the larger brake pads as compared to the smaller.

There is absolutely more braking force in the rear than previously.

As far as the ABS coming on,.....well, the ABS will come on (engage) at EXACTLY the same "time," which is at the limit of tire traction. The ABS has absolutely no clue what kind or size of caliper is squeezing the rotors. All the ABS "sees" is that the wheels are no longer spinning.

The sense that I get when making a max-performance stop is that instead of diving, the car just kind of "hunkers down."


Regards,
KoreaJon

romandian

that makes me want to play with the pressure limiting valve for the rear. last time i looked, i couldnt find it. is there one at all?

KoreaJon

Thanks, Lionelhutz!

I took the advice or another poster in the thread, and welded on another backing pad to the outside brake pad. It made a significant difference to where the pads sit in the caliper bracket!


Regards,
KoreaJon

KoreaJon

I think that it depends on the year. On mine it is located just ahead of the master cylinder. On later models, I think that it's built into the abs module.


Regards,
KoreaJon

SuperTom

Any updates since its been a few months. I just installed a wildwood 6 piston front kit and now have to do something with the rear brakes. Went over my budget so this is up my alley. I already have the stock front c5 calipers that I would modify then purchase some c6 z51 rotors. Have also considered a budget c6 zo6 rear brakes if these are the correct calipers from autozone http://www.autozone.com/brakes-and-t...03_2362_46162/ . But still interested in your setup as that would be the least expensive

Caveboy

KoreaJon

Well........I love how well the brakes work. I can stop absolutely on a dime...If I really stomp on the brakes, the passenger had better close their eyes, just to keep their eyeballs from popping out.

On the other hand, I've encountered some...annoyances.
1. When I really heat the brakes up, I can hear some very pronounced rubbing until they cool down again. This means that the rotors are "growing" in at least one dimension. What I discovered is that the rotors diameter actually grows enough to rub the underside of the caliper.

I don't like this at all.

The options then become a.)clearance the underside of the caliper body to provide space for the rotor to grow, or b.) reduce the diameter of the rotor.

I did NOT want to shave any metal off of the caliper body....I don't know enough to know when the metal is too thin to carry the stresses imposed by hard braking. And the other annoyance is:

2. In the picture below you can see that the caliper bracket isn't QUITE tall enough to get the pads to the very edge of the rotor.
The rust-colored band on the perimeter is 5mm wide.




One option would be to have a custom caliper bracket made that would move the caliper outboard by 5mm. I chose to have the rotors diameter reduced by 8mm, and use the other 1mm as a chamfer area.



I'll wire brush the rusty ring this evening, and pretty it up with silver paint.

The other thing that I don't like is that where the brake pads didn't get quite all the way to the outer edge, they ended below the inner edge. See this picture, where the pad has the ridge on the inner (right hand) side?



It looks like they might contact the backing plate as they continue to wear, but it's just the angle of the picture. The fix for ~this~ little issue is to have caliper brackets that will move the caliper outboard by +/- 5mm. Of course THAT would obviate the need to have the rotors turned down....

Sooo...having the rotors turned down means that I have TWO custom pieces in the rear brakes:
1. The outside brake pad, with the welded on (additional) backing pad, and
2. the turned-down rotor.
I really don't like this, because it makes the inevitable brake job more technically difficult. ie; these are not "off-the-shelf" replacements.

I ~believe~ that milling down the outboard side of the caliper mount bosses on the hub will negate the need for the welded on backing pad. I need to measure the thickness of the pad, and measure the height of the boss where it can be milled down before I know for sure. I'll report back the results of what I find.

This does not, of course, address the diameter / clearance issue, but at least when doing a brake job, there would only be one special operation instead of two.



IHTH,
Jon

SuperTom

Thank you Jon for the honest feedback. Doing my own research the front c5 rotor is 325mm and the z51 rear is 330mm hence your 5mm rust lip. It seems the only way to make this work easier is to use the front rotors in the rear BUT you would lose your e-brake. If you were going through trouble/cost of having brackets made I'd push it out 15mm then you could use the 350mm C6 Z06 rear rotors. Seems like to much trouble even though they are small issues I have too many small issues piling up and would annoy me in the end. I think I am going to take the risk on those reman. autozone z06 calipers for $150 a pop. Even if they don't come with any corvette wording is a plus as I just want to G2 paint them red anyway to match the Wilwoods upfront. And ebay my used calipers to recoup the cost.

KoreaJon

Yeah, the small issues can become very annoying...

I had the rotors turned down yesterday...cost me $50, but at least I don't have to worry about the caliper breaking under heavy braking due to my having removed material in just the wrong spot....

I probably will have a set of caliper brackets made to push the calipers outward and inboard relative to the rotor. This would obviate the need to shave the bosses on the caliper brackets and welding the additional backing plate to the outboard pad. It would make the installation "plug and Play," and be very easily reversible.

I'm VERY interested to see what you find regarding the AutoZone calipers. Would you post some pics of what they look like?


Regards,
KoreaJon

SuperTom

well I went to place my order the autozone calipers and was excited to see I could get 20% off using USA20. Total price for both 259.18 including shipping and core fee. However they are out of stock of both

KoreaJon

I got everything cleaned up and reassembled.





The lighting is shtitty, but there is the appropriate amount of clearance between the calipers and the rotor.






I'm at the tail-end of a H/C swap on the engine, but when I get it back on the road, I'll give another report.


Thanks,
KoreaJon

SuperTom

EDIT nevermind they don't have them in stock ouchhh!!! Looks like I will have to fork over bucks for the real thing



quick update on my journey Cardone part #'s 18-5178XR and 18-5179XR and come already powder coated red https://www.cardone.com/Products/Pro...der+Coated+Red

purchased from northern auto parts http://www.northernautoparts.com/part/2a-18-5178xr . Came to $320 for both including core fee and shipping. I will hold off on purchasing rotors, pads, lines until I see them but looks an inexpensive c6 z06 upgrade.

There is also Cardone part # 18-5178, and 18-5179 those are a lil cheaper but don't come powdercoated and was hard to find any in s