Technical Question on Brake Pad Bedding

Oh man...I'm having almost the same issue with the aftermarket p*** caliper on my c20...i spent hours on it with out success.
Good luck

 

Thanks good luck to you as well. I'll keep posting as I continue working on this.

 

I forgot to say the cpp bracket has a 1/16 gap where the caliper slides along on the top knob. The speedway did not maybe that's where it was binding up and causing the caliper to not slide. I don't know if on a hard stop I would get a clunk noise with the cpp bracket. Does anyone know?

 

There was a thread here a bit ago, someone from England, who bought (not sure if from Speedway or not) a disc kit that also came from CPP.

IIRC the caliper bracket needed to be tweaked to get things correct, he found this out by calling CPP directly, I'll see if I can locate the thread, maybe you two can compare notes?

 

Thanks the cpp bracket looks like it will work without modifications so long as a 1/16th gap where the caliper slides is acceptable. Just not sure if a gap is supposed to exist or not. I gave up on the speedway one since the caliper piston on the driver side doesn't go in as far as the p*** side so I will have issues finding the right pads. I am outside of Napa now. I hope to return the speedway calipers and brackets.

 

Looks like I've gotten some threads mixed up, I found the one from the guy in England, he had other issues with the CPP stuff.

Can't recall where I read about the other issues.

Best of luck.

 

Thanks I'll keep at it just got some Napa calipers and pads and heading back to test fit with the cpp bracket

 

With the cpp bracket and the new Napa semi metallic pads and the speedway caliper the driver side now spins. Not much clearance between the pads and rotor but it spins easily by hand. Just don't know if the 1/16th inch gap between the caliper surface and bracket can cause a clunk when stopping. Anyone know? Here's a photo.

 

There shouldn't be much clearance, if it spins freely that's good, as for the gap, it will get "adjusted" by the caliper the first time you use the brakes.

 

Thanks! The gap I'm worried about is between the caliper surface (the same one some of the pad edges ride along) and the flat knub on the caliper bracket. The speedway ones have maybe 0.020" clearance there. I can see in a hard stop the caliper shifting upwards and hitting the caliper knub. I know to put grease there but don't know if 1/16" clearance may cause an issue with noise. I suppose once it shifts up stopping in reverse would have the opposite effect and the caliper would move down and hit the knub. Not sure the pin/bolts prevent this motion of the caliper or not. I certainly can't make it move up and downwards by hand.

 

Anyone have advice on that gap I mentioned with the cpp bracket?

 

I don't think it'll be an issue

 

Yes, put it together and drive it.
Speculating only delays the outcome.

 

Thank you!

 

Did you get the brakes finished?

 

In this pic it looks like the caliper is higher than it should be. It looks like part of the pad is above the rotor. I don't think this is normal.
Remember on disc brakes after stopping and the pads only go back maybe a thou or so allowing the rotor to turn. Unlike a drum set up there are no springs pulling the shoes back to rest. As far as a perfect match up of the pads and the rotors I don't think any kit out there that is m*** produced will align up perfectly. After a few stops all will be well.

 

Thanks, still working on it (I had to stop all work the past 5 days to do resume updates and job applications ughh!). I will post some photos later tonight.

 

There should be rubber bushing/o-rings in the caliper ears where the mounting bolt p***es thru , they'll cushion noise transfer..yep , i'd be nice if the caliper mounting plate was a little thicker and fit the caliper a little closer but that's an aftemarket adaptor , very seldom perfect..
dave

 

Thanks definitely o-rings and bushings. I lubricated them really well with synthetic grease.

 

Ok so I took photos of the new setup which consists of CPP brackets, NAPA calipers, NAPA semi-metallic pads and the Speedway rotors. The pads look nice and parallel, the rotors spin nicely, and the calipers moves in and out, however the pads do not fully cover the rotor. I can see how the pads' edges won't wear with the rest.




In this instance what advice would anyone have? I could grind the threaded roid a bit and then enlarge the lower hole so that I have slop to push the entire ***embly towards the rotor hub center. I'm concerned I may mess up the roid and causing it to not sit parallel against the spindle surface.

 

What's a roid ?
That word is all over this thread.

Usually the pads sit 100% on the rotor and the rotor's OD is beyond that of the pads. This develops a ridge in the rotor's edge as time and wear and rust do its thing. At first thought the caliper needs to go closer to the center, but that's difficult, however doing so would close the gap at bracket to caliper. Second thought would be maybe the rotor is lacking on OD.

There may be a problem as the pads wear. i say May because i dont know and have not seen that before. as the pads wear and develop a shelf over the rotor. Most likely it will just wear away and flake off being so thin.

Out of everything I see there the one thing I'd worry about is the pads hitting the threads of the caliper bolts. It will Buggar the threads and you'll catch hell removing them some time in the future.

If you're worried about that gap, weld the bracket face and file it to fit better.

Or just make your own brackets that fit without any compromise.

 

Thanks again for your help. Some manufacturers call the upper spacer that is threaded a roid. I could grind that roid/spacer down a little so it pulls the bracket towards the hub center and enlarge the bottom hole. I don't know if I'm going to mess it up.

I imagine the brake pad edges will flake off as it wears like you mentioned but this may be asking for trouble, I don't know. The threads on the caliper pin/bolts are clear from the pads. In the photo there is anti-seize that formed the threaded looking pattern on the bolt since I put anti-seize in the threads of the caliper brackets and some pushed through.

Any thoughts if my plan to grind is a good idea as shown in the photo below?

 

Roid... sounds like something you rub a certain cream on and avoid ghost peppers for a while....

I'll throw another "engineering" term that goes along with the funky brackets. Look up "kluge".

 

Haha that's funny.

 

Does anyone know what I should do? Keep grinding away at the caliper brackets?

 

run it

 

It's tempting I've dragged this on for too log. pun intended... yet there is something not satisfying about the rotors not extending fully past the pads. I don't know.........

 

Definitely an example of a collection of parts that do not play well together. Take the pads out, hold them in a bench vise, hacksaw anything off that extends past the rotor. Hit it with a blast of spray paint first (while on the car...) or mark it with a sharpie as a guide.

 

Thanks I had looked at photos of the speedway parts and it looked like the brake pads were overhanging with that set up as well.

Would it be too risky to grind the caliper brackets like I suggested in the red markups in the photo above? I could buy another set if it came down to it. It seems like the right thing to do given I'll need to replace pads some day.

 

I measured the rotor diameter to be pretty much 11" exact. I went to NAPA this morning and they did not have any 69-72 Chevelle rotors in stock but they call for 11" diameter and I was told those dimensions run pretty much spot on.

At this point all I can think of is to grind the caliper bracket spacer down evenly by 0.100" and then grind the bottom hole so it will slide in a little. The top of the pads are needing to move inwards (towards the hub center) more than the bottom.

I took the caliper brackets off and have them with me at work and will grind them down with a file as careful as I can.