C2Dude

This is really a continuation of a previous thread. I pulled the front calipers from my 66, found the right one to be leaking. A club member has two SS O-ring calipers he is selling me tonight. Out of curiosity I measured the rotor widths with a machinist caliper, came up with 1 3/16" passenger side, 1 5/32" drivers side. Searched the forums and it would seem as if 1.215" is the minimum thickness which I believe translates to 1 3/16". So if I am correct, I need rotors. The previous owner had obviously done this at some time as all the rivets have been drilled out. So with the caliper off I should be able to tap the rotor off without disturbing the hub. I can order two new slotted rotors from Ecklers on sale for 118. each. mount it, apply the lugs and check it for run out (< 0.05" I understand). Shim it if it exceeds that amount and I'm good....RIGHT?

MikeM

You are wasting your time and your money assuming your specs are correct. New rotors won't fix a weak stopping situation like you described.

Tampa Jerry

There is no reason to get slotted rotors. Save your money and buy regular rotors from the major vendors. They should cost about $50 each or so. It is easier to check run out as well with stock rotors. Jerry

C2Dude

I hear you Mike, this is a developing investigation. As I pull things apart to correct the big picture of poor braking, I am finding other things that I "think" should be corrected. In this instance it would appear that the rotors should be replaced. I pulled them off and began cleaning up the hub surface that had surface rust on it and discovered that the drivers side hub when spun, is lumpy. The passengers side is smooth. So the next question is does lumpy indicate worn wheel bearings, worn hub or both? Is it necessary to replace both sides while I am at it or just the sketchy side?
Thanks

C2Dude

Your right Jerry. I have to constantly remind myself about the difference between marketing and reality. Another member of our Corvette club has two new OEM rotors he will sell me at a good price. Mentioned to Mike about the lumpy feeling drivers side hub I found while spinning it (rotors removed). Any opinion about replacing the bearings, hub or both.
Thanks

benrep

The wheel bearings should always be inspected and re-packed and new seals installed when the brakes are replaced. I would mount the new rotors to the hubs (really clean the rust off of the hubs), with the lug nuts torqued to spec and true them on a brake lathe to the hub. Put index marks on them and the next time thy come off you can put them back on where they are true. Mark them left and right also. A good shop can do this for you with the bearing races only in a clean hub. New races if you are changing bearings. Never shim a rotor for true. They will probably have to kiss them a little but true to the hub is the only true. They should also be cleaned of any oil etc. before machining then really cleaned well after.

kellsdad

C2Dude,
Let me reiterate what was said above about doing the wheel bearings when you do the brakes. Note that the caliper is fixed (not floating like more modern cars) and the rotor movement is determined by the wheel bearing. So, if the bearing allows the rotor to run in and out as it turns, it will cause the pistons in the calipers to move in and out with each turn. On original style calipers (i.e., those without o-rings) this can lead to air being drawn into the caliper causing a chronic soft pedal situation.

C2Dude

Noted. I will order two sets of Timken bearings today and pull the hubs after marking them L&R. Pull the races from the hubs, mark them R&L and clean them (paint them??). Install the new bearings when they arrive. Look for an automotive machine shop to true them up after assembling hub and rotor, torquing down the lug nuts. Place index alignment marks on trued rotor/hub assembly. Then it's reassembly time.
Thanks

benrep

You should first watch a couple of YouTube videos on wheel bearing replacement. You have to drive the races out with a suitable tool. The new bearings come with new races that need to be installed with the proper tool. You may want to have the shop do this part. The bearings are all the same until you run them, then if you re-pack them, you don't mix them up, and the races don't get disturbed. Packing needs to be done properly, by hand is an art, a wheel bearing packer is much better. Seating and adjustment are critical not for a novice. If tapered roller they need a slight pre-load. Watch all you can find, look for bearing companies or sellers videos, not Bubbas.