When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Snug up the bearings a little on the fronts, hold the rotor with the lugnuts, indicate the brake surface while spinning the wheel, mark the high and low and how much it runs out, try moving the rotor around a few positions to get the best runout condition and paint a stripe on it and the hub so you know which way to always put it on.
Make or buy some shims stock (buy tapered rings from NAPA or cut shim stock/beer cans and install on the low side studs
keep adjusting until your less than .005" runout
All this talk is concerning me. I'm kicking around different ideas for my brake options and now I have to worry about runout too. Sheeeeesh....
Boy do I know what you mean. I started a year ago with a brake caliper leak. I've rebuilt the front suspension, the transmission, changed wheels, (a few other things I won't go into) and now I have a brake line fitting leaking so the brakes still don't work. I've driven the car less that 20 miles in the last year.
I love a good soap box ramble. I think I understand what you guys are talking about. I'm less worried about it now.
Glad we could help.
The issue is that the C3 was actually a very advanced car for its age. Four piston fixed calipers are a great system. Just with the lip seals used at the time, run out has to be held to a minimum. It takes time and $$$. In fact, the C4 went to floating calipers and arguably, the brakes were not as good as the C3 but the better tires made up for the difference.
Is the only way to secure the hub back to the rotor to rivet them back like the factory did? I don't think I have the ability to do that, but it would be nice to lock them in once it's shimmed properly. Save me from a screw up later.
Is the only way to secure the hub back to the rotor to rivet them back like the factory did? I don't think I have the ability to do that, but it would be nice to lock them in once it's shimmed properly. Save me from a screw up later.
Drill, tap and use countersink bolt....or those cheap stamped rings that every GM car used for 25 years that go on the studs....like a big push clip.
Is the only way to secure the hub back to the rotor to rivet them back like the factory did? I don't think I have the ability to do that, but it would be nice to lock them in once it's shimmed properly. Save me from a screw up later.
That system is totally different that stock. The Dynapro caliper has a piston surface of 5.06 in^2 compared to 5.56 in^2 for the stock caliper. So you will lose about 9% of clamping force compared to the stock caliper. Not a good deal.
The stock rotors are good. Very good. I have never seen any definitive tests that prove that slotted or dimpled rotors are any better for street use. I did replace mine with new NAPA rotors but only because we did the trailing arms at the same time. For my rears, Gary set the run out to .0025" on both my rear rotors. One required a .003 shim, the other did not. He then fastened the rotors to the hubs with bolts so they don't move.
I replaced the front rotors myself. Drilled out the rivets, fastened the new rotors to the hubs with lug nuts. Check run out using a dial gage. Took a couple of shims but got it down to ~.002 on both.
I read some articles and even watched a video on the slotted or drilled rotors vs solid... The reality is that it actually hurts more than it helps for a street car. They are popular based on looks not function. the brake companies are loving it because the slots and holes wear everything out quicker as well as increase to likelyhood of warping. They only help as reducing brake fade in racing applications at the costs mentioned above.
This and the fact that my factory 74 rotors even with 110,000 miles on them appear to be in fantastic shape which has been unheard of with any newer car Ive owned even with half that mileage, tells me the grade of steel used on the oem rotors is far superior to the lower grade russian/chinese steel used now days.
Last edited by augiedoggy; Feb 11, 2021 at 01:04 PM.
I will say this and this is just an opinion. I have driven cars with crappy brakes. They never scared me. I knew they were junk and adjusted my distance. I was driving a car once and got on the brakes a few times in a row. As I was coming to a STOP sign, the brake got hot and faded on me REALLY bad. Up until that point I had never really thought about brakes acting different while driving from one stop to the next. At that point, I WAS SCARED. So if you gave me the choose between better brakes that may fade or worse brakes that wouldn't fade, I would take no fade.
But your point that most people change because of looks is correct. And in this case, I'm probably most people. I would like to spend a few thousand on some really nice Bear brakes, but the funds just aren't there.
I will say this and this is just an opinion. I have driven cars with crappy brakes. They never scared me. I knew they were junk and adjusted my distance. I was driving a car once and got on the brakes a few times in a row. As I was coming to a STOP sign, the brake got hot and faded on me REALLY bad. Up until that point I had never really thought about brakes acting different while driving from one stop to the next. At that point, I WAS SCARED. So if you gave me the choose between better brakes that may fade or worse brakes that wouldn't fade, I would take no fade.
But your point that most people change because of looks is correct. And in this case, I'm probably most people. I would like to spend a few thousand on some really nice Bear brakes, but the funds just aren't there.
But you have to really but doing a LOT of long braking for this to really be an issue.. Its not something that would typically happen on the street. This is why street cars dont typically come with these features because auto manufacturers would probably statistically have to deal with more issues and warranty repairs if they did. It is something you would see on a track through. I get it though.. I tried to convince myself I needed them too because they look so cool on open wheels. and it looks like your using some thick wheel spacers there so the brakes would look even smaller I would think than normal.
Last edited by augiedoggy; Feb 11, 2021 at 06:53 PM.
Is the only way to secure the hub back to the rotor to rivet them back like the factory did? I don't think I have the ability to do that, but it would be nice to lock them in once it's shimmed properly. Save me from a screw up later.
Do we have to? Mine were drilled out well before I got the car. The rotors were held on by the wheels.
I had to use 2" adapters to get the wheels to fit. If I ever get to drive it again, I'll find out if it worked. The brakes do look kind of small. But who knows, I may never change the rotors.
Yeah, 6K is a few right? Maybe it's a couple few. Is that more like it. I think they make good stuff. People brag about them. Maybe that's because they spent so much on them.
I've never taken it to the track, but I would like to one day.
