C3 Brake Rotors

[Steve B.]

I have a 1976 Coupe and spent last winter performing a comlete engine overhaul, which to many I have to say thank you for your generous and expert advice. This winter I thought I'd take a shot at replacing the brake rotors. First off is this a job that someone such as myself (a very part time mechanic) can accomplish at home in a small garage with limited tools? If so, what help can anyone offer regarding the procedure? Any advice from the purchase to the testing would be greatly appreciated.

Thanks again,

Steve Boyd

[Michael W.]

Re: C3 Brake Rotors

First off, why do you need to replace the rotors? They very rarely need to be changed (or even resurfaced for that matter). I've got well over 100,000 miles on my '73 and still have two of the original four.

If you do change them, make sure that the new ones are first measured for run out while installed on the hub, and machined as a pair of they are out of tolerance.

There's lots of info in the archives here, and plenty of mis-info on other websites.

[Jim T.]

Re: C3 Brake Rotors

Steve I agree with Mike on replacing/surfacing rotors. I have 96K on my original owner 68 and it has the original rotors. Have 160K on the front original rotors of my original owner 70, and 102K on my 85's original rotors.

[Todd H 26112]

Absolutely

Presuming they need it - if you can tackle an engine overhaul - this should not pose any problem. But I'll warn you of a couple things while you are in there.

1 is that you may discover a 'mess' w/ your rear parkign brake compontents which may tempt you into servicing those as well. That's a tricky one and a small subject unto itself but many people also manage those at home as well.

Periodic bleeding can also be beneficial. I've also found new brake hoses to make a VERY noticeable difference in brake performance and feel depending on how old your old ones are. And the nice thing is these have the added benefit of being the uniquely recognized 'safety' items on your car and thus not judged so get what you please (does this allow SS hoses to be used w/ no deductions? - anybody know?)

You may need to rent a special tool to pull some of the rotors if there is rust - it can be purchased or rented or borrowed for free from a parts store or something. Sometimes a few well placed raps can free them which I'm not above doing but then there's an off chance one might crack or shatter.

My rotors seem pretty good after many miles but I may be forced to replace my rear rotors unfortunately. While none needed resurfacing or replacing - I did terribly need some resurfacing to teh inner drum parking brake surface on the rears. I had to dig to find a shop that could resurface such small drums. And I gave them SPECIFIC advice NOT to turn the rotors as well. THey of course did anyway and now I suspect I have the dread runout problem w/ the calipers so I may just brake down and get a whole new set all around. Anyway to make a long story short - as others have mentioned - ensure you really do need new rotors or whatever.

I own other makes of cars and some routinely need new rotors every 50K or 100K or so - it depends somewhat on the design and somewhat on how it's driven and somewhat on the pad material selected and perhaps even teh manufacture of the rotors themselves though that last one is a hard one to pin down and quantify. My point is your mileage may vary from vehicle to vehicle and vintage Vettes are pretty easy on rotors.

Good luck,

[Joe L.]

Re: C3 Brake Rotors

Steve-----

As others have advised, you should change the rotors only if you need to do so. The rear rotors, in particular, should NEVER, EVER be changed unless absolutely necessary.

You can assess the condition of your existing rotors using a micrometer and a dial indicator, with stand. If you don't have these tools, you can purchase them quite economically from sources like Harbor Freight Tools. The inexpensive ones will be "foreign" sourced, but they'll work quite well for your limited use and requirements.

All of the specifications for the rotors will be found in your factory service manual. If your rotors meet all of the factory specs, as is likely, you don't need or want to replace them. My rotors on my original owner 69 have 200,000 miles on them and are near-perfect with ALL specs.

By the way, circumferential scratches or scores on the rotor surface DO NOT mean that you have to replace or resurface the rotor. Unless they are real wide and/or deep, they won't harm anything, at all.

[Craig S.]

Re: C3 Brake Rotors

I agree with everyone - my 74 has the original rotors (only 75000 miles though) and they literally have zero wear. My 67 needs new rotors, only because someone else that DIDN'T know what they were doing FIXED them in the past, drilling and turning them off the spindles. The solution is new rotors, riveted to the spindles, and turned as an assembly as GM did....Craig