Bearing assemblies have been rebuilt but still have rotor wobble on new and cut rotors so going to shim the rotors now. What name of tool should I google to mic my rotors on the car as I have never done this before and about how much shoud it cost? Do stores tool loan them? I'm in Waterford, MI. What is good to use for shims? Also, what is a simple check or procedure for a power booster for working properly since EVERYTHING ELSE IS NEW!!!

 

You want a dial indicator with a magnetic base. This will measure rotor runout on the rotor. I use shim stock in varying thickness to shim my rotors. They are all within .002. now. I doubt any store would loan them but you might find someone who will loan them to you. Just atke care of them. They are a precision instrument. Try not to drop it or kick it around. A forum friend just got one off ebay for about 35 bucks for the indicator and base. You can also spend over a hundred for one.

 

You want to use a dial indicator to measure the runout on the disc. Any shim stock will suffice. It's usually not recommended to have rear rotors machined since most production shops can not maintain rotor parrallelism requirements, which sets you up for endless piston air pumping issues until you just replace the damn rotors with new, uncut rotors.

I have no idea if you can rent the dial indicator and stand, but I don't see why not. They're not an unusual tool, and you could buy a cheap one with stand for probably around $75.00.

 

http://www.amazon.com/Dial-Indicator...8&s=automotive

Not sure how much you want to spend here's a good web site.

 

Where do you purchase shim stock? and what type to purchase?

As someone else suggested in an earlier thread, I just purchased a
dial indicator with a magnetic base from Grizzly Co. It also came
with a dial caliper. Total cost with shipping was $41.20.
Their item no. is H3022.

 

Where can you get the shims and is there any thread or website that tells you how to do this. I think I have the same issue with the brakes on my 75 ---- thanks

 

Google "corvette rotor shims" you'll get a hit from a corvette fever how to article.

 

I've seen a few threads on here where they use shim stock cut from beer cans.

 

What about a "how to" on checking the if the power booster is working properly, or, what are some tell tale syptoms of power booster failure vs. MC problem.

 

How do you diagnose a bad power booster

 

With a totally bad brake booster you will have no power assist when applying the brakes. Very hard pedal and very hard to stop the car. Much like having a death grip on the steering wheel and standing on the brake pedal with both feet just to get the car to stop. The Master cylinder is a little more difficult to diagnose. There are a number of symptoms that could indicate a master cylinder is bad. Separate the master cylinder from the booster if you see any brake fluid there replace the master cylinder its bad. Other symptoms such as a soft pedal, pedal going all the way to the floor, could also be a master cylinder problem or a problem with the brakes lines leaking, caliper’s leaking, or air in the brake system caused by excessive rotor runout.

 

If the booster is bad your brake pedal is hard to push. All the booster does is assist (with vacuum) to make braking easier.
You can get a magnetic base dial indicator at Harbor Frieght a lot cheaper than anywhere else.
I used a Grapette cola can ( some use a beer can) to cut out the shims when I did my rotors.
I also used white paint on one of the studs and marked a white spot on the rotor when I got done, so that if I ever took them off, I would know the correct position when I put them back on.

 

got mine on fleabay for $50 after shipping.... excellent tool to have.

 

I purchased a cheap dial indicator/mag mount from HarborFreight Tools. It's made in china, but hey, I just needed to use them once. Google them, there's quite a few in MI, plus available on line.

I purchased a Brass sheet .005 4"x8" from Ace Hardware for $2, but it took 30 minutes to find it, no one knew what I was talking about. It was by fluke the clerk found a display with brass/tin/ss metal pieces, pipe, etc. It was packaged in an area and labelled as KMS (or KSM?) Metal Product or something like that. They did actually have a package called Brass shims, but didn't label the thickness, I guessed it had 2 .005 and 2 .002 small sheets. But I opted for the single .005. It worked fine for my 2 front rotors.

I used tin snips to cut a small circle (used a bleach bottle cap as a drawing guide). I then used a 1/2 inch drill bit to notch a hole in it to clear the bolt threads so it wouldn't bind up.

I now need to do the rears..

Hope this helps out.

Criss

 

You can buy shim washers from Mcmaster Carr in any thickness you might need, down to .001". They come in brass, stainless, aluminum, whatever you want.

 

I did! Each circular shim I cut was .003 thick. Didn't need any thicker to get rotors within .002 of runout. Used nothing but the best imported beer can for my ride!
Eddie

 

http://www.corvettefever.com/techart...brake_upgrade/

 

First thing I would do is check the rotor thickness since you said they were turned. 1.250 is new and 1.215 is trash. If they are close to 1.215 then consider new rotors. With that said don't expect to have new rotors, either USA or imports, with no runout.
I'm assuming this is for rear rotors? regardless they can be dialed in as long as the spindles are not bent. Be sure there is no rust or burrs on the mating surfaces. I only dial in rotors when I can secure them to the flange or hub with flat heads. I do not rely on the lug nuts to hold the position, this will change everytime you remove a wheel. I know many use the lug nuts only but if you want the better job bolt them on. You don't need to rivet them and riveting is only good when you can turn the spindle and rotor as one. Bolting on gives you the opportunity to remove and dial in the shims.
If you have never used a dial indicator there are some things to learn. First you have to 100% sure there is no movement in your fixturing, the slightest pressure will throw off your readings.
Next I know the chinese indicators are cheap, I have some too, but they are junk. I've had the 2 or 3 here last only a short time and then start sticking. This is worse then the first problem because the reading will appear good then start to drive you crazy!
I use SS shim stock from MSC, it comes in kit form from .001-.020" I punch out the holes with a sheet metal hole punch kit. These 2 will set you back about $80- $100 so I would look around a good hardware store, You'll need a micrometer or caliper too.
It is important to get the runout under .002" I've heard up to .005" is good but you're going to be the one driving the car so why do it 1/2 way?
If you don't have any of this stuff and don't plan on doing much wrenching on your car then find someone to do it for you. If however you plan to really work on a vette you're going to need the indicator, micrometer, calipers, and a lot of other tools.


Here are some pictures from a front setup

 

What are you using for the flat head bolts in the rivet holes? Did you have to cut threads into the hub or ar you using nuts on the back?

 

I dont understand the need for shims. Just exactly where are they being used? Im using your pictures because they lead me to believe that most of time the rotors are seperated from there hubs and cut, then re-assembled. There is not any need to seperate the hub from the rotor unless a new rotor is used. Proper proceedure with a new rotor would be to re-hub the rotor and then cut them. With a good machine they will be dead nuts every time. And by the way all rotors should be cut at every pad change to make sure they are straight.