Rear Brake Rotors

Fuelie74

Well-known member
Joined
May 7, 2008
Messages
770
Location
Monroe, WI
Buying a new set of rear rotors for my 74 and noticed most don't come with the rivet holes. I want to bolt them on when I shim them. Can I just use my old rotors for a pattern and drill the holes in the ones that don't have rivet holes?
 
Sure, why not.

Just make sure the mounting flange face the 5 studs go through is about 1/4 inch thick and slightly thinner then the front rotors.....

otherwise you have a set of front rotors, and you supply house dunno the diff....

:bonkers::shocking:
 
I just drilled my new rotors and used a old spindle for a template, your old rotor will be just as good.
Do not drill into the spindle flange when you remove (drill) the rivets out. Use a centerpunch and use a drill big enough so that the rivet head pops off when the drill breaks thru. You can then pull the rotor off and then beat the rest of the rivet out. That way you're not making the hole any bigger, as it is now it's already big enough for 3/8" thread.
A few photos of the rotors and setup for runout:
http://www.vettemod.com/forum/showthread.php?t=3013

I did not have to use shims, runout was under .004"
 
Thanks. I thought it would be ok but wanted to double check before hitting it with the drill. I all ready removed the rivets. My rear rotor runout is .020 and .010 on the spindle faces. Needless to say my brakes are in need of bleeding every 150-200 miles. So I will probably be in need of shims on this one.
 
Because of the two holes for the parking brake adjuster you can't reposition (rotate) the rear rotors to minimize runout. The front rotors can be mounted in five different orientations.

Are you sure your wheel bearings are ok ?? .010" on the spindle is quiet a bit.... can you point the indicator on the spindle flange OD and move the spindle ? How much play do you see on the dial ??
 
I believe the bearings are ok. I am planning on replacing them but it keeps getting put of various reasons. I don't remember what I measured on the spindle. I will try to remeasure it this weekend.

My brake problem started as soon as I got the car. Stupid me thought I would take the rotors into work and clean them up on the brake lathe during lunch since they had a little rust from sitting so long. I put them on the lathe and remember thinking man these are really far out. Not knowing that they were cut on the car. Ever since I have had a problem with rear brake noise and air in the rear brake lines.
 
At least you know why you have this problem :thumbs:

I'd just clean the spindle mating surface and install the new rotor, then measure runout. If it's not all that much - maybe you're lucky like I was - and the runout is ok. If it needs a .002" shim I'd try to clean up the mating surfaces a little more, maybe with a DA grinder or a sander... 60 grit should do the trick, you only need to remove .001" on the spindle to change the runout on the larger diameter rotor by .003" or .004"..... . You can do that once the studs are removed, just bolt the rotor on using the 3/8" bolts that replace the rivets.

Replace the wheel studs with Moroso or ARP stuff.
 
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