HELP: 1970 front brake rotor replacement
#1
HELP: 1970 front brake rotor replacement
Ok... to my surprise when doing a rotor swap I found that the rotors are riveted to the hub. I have new cross drilled and slotted rotors but am having trouble finding someone that can drill out the old rivets and install new ones. How could this be done without warping the new rotors without doing all 5 rivets at the same time?
I have a machine shop that can drill them out but doesn't have the rivets. What have you guys done in the past? Any suggestions would be helpful.
I have a machine shop that can drill them out but doesn't have the rivets. What have you guys done in the past? Any suggestions would be helpful.
#2
Team Owner
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You can aattempt to install rivets on your aftermarket rotors, but the bearings, calipers, and lug nuts will keep them in place.
No disrespect, but since you were not aware of the factory installation, are you confident about your rotor swap?
#3
Rotors cannot be simply swapped on a C3 as is done on modern cars. They were riveted together by GM to allow the final machining of the rotor face to eliminate runout. Unless you are prepared to re-machine or shim the new rotors after installation, leave the originals in place. They almost never wear out, basically good for the life of the car.
Slotted and drilled rotors do not improve braking BTW, just bling.
Slotted and drilled rotors do not improve braking BTW, just bling.
#5
That's factory. All four are riveted unless someone has been there before you.
You can aattempt to install rivets on your aftermarket rotors, but the bearings, calipers, and lug nuts will keep them in place.
No disrespect, but since you were not aware of the factory installation, are you confident about your rotor swap?
You can aattempt to install rivets on your aftermarket rotors, but the bearings, calipers, and lug nuts will keep them in place.
No disrespect, but since you were not aware of the factory installation, are you confident about your rotor swap?
I tend to differ about just the bling of the cross drilled rotors. I have used these on at least 10 other cars with a significant improvement in stopping ability. Pads wear out sooner but its just the price you pay.
I have not taken the rear tires off yet to see if they are also riveted. The funny thing is that the new rear rotors only have holes for the lug studs. Only the new front rotors have rivet holes.
#8
#10
When I bought the car the brakes were bad. They reminded me of the 4 wheel drum brakes back on my 66 SS Chevelle. No leaks but just doesn't want to stop. Pads looked almost new. The surface looks a bit glazed and Thought I would go through everything. I started with the fronts. I have new SS brake lines with new rotors and pads. This usually takes me about 20 minutes per side with everything but this has now turned into a real challenge.
Also, the back reservoir on the master was a little low an I suspect the prior owner put a new break line on the back.
When they mention shimming the rotors..... where exactly does the shim go? Is this between the rotor and the hub to push it out? Or is this just a spacer between the hub and the wheel?
Also, the back reservoir on the master was a little low an I suspect the prior owner put a new break line on the back.
When they mention shimming the rotors..... where exactly does the shim go? Is this between the rotor and the hub to push it out? Or is this just a spacer between the hub and the wheel?
#11
Race Director
You do not need the rivets, use a large drill bit to cut the tops of the rivets off and just drive them out. Then drive the studs out and the hub and rotor can be separated.....Clean the hub surface and place the new rotor on the hub and then re-stud it.....this should make a minimum amount or nothing run out....If there is run-out have a parts store or machine shop that does brakes true them in on their rotor/drum lathe...Forget that shimming procedure you can waste all day with that issue.....Get them machine trued up if necessary
#12
The shims go between the rotor and the hub/spindle.
#13
Le Mans Master
You do not need the rivets, use a large drill bit to cut the tops of the rivets off and just drive them out. Then drive the studs out and the hub and rotor can be separated.....Clean the hub surface and place the new rotor on the hub and then re-stud it.....this should make a minimum amount or nothing run out....If there is run-out have a parts store or machine shop that does brakes true them in on their rotor/drum lathe...Forget that shimming procedure you can waste all day with that issue.....Get them machine trued up if necessary
#14
Drifting
I would bleed the whole system before I started replacing parts, no question. If there's glazing, remove it with the pads Mike mentioned (Roloc?). Some 120-150 grit sandpaper should work also, I think.
Honestly I find the search function on this site to be about the only thing that's terrible - returns an astounding amount of irrelevance.
Honestly I find the search function on this site to be about the only thing that's terrible - returns an astounding amount of irrelevance.
#15
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#17
Drifting
I have found 2 issues with these brakes:
#1 - hard to bleed. Solution - use Motive Bleeder
#2 - Insufficient vacuum to booster. Solution - adjust idle mixture for highest manifold vacuum.
If you have hard pedal, I believe #2 is your problem.
Anyways, that's my experience.
#1 - hard to bleed. Solution - use Motive Bleeder
#2 - Insufficient vacuum to booster. Solution - adjust idle mixture for highest manifold vacuum.
If you have hard pedal, I believe #2 is your problem.
Anyways, that's my experience.
#18
Racer
I use a shop in Spring on the north side of town, they do a lot of work on classics and corvettes. They did all the work on my 72's brakes, new pads, rotors, lines, powerboost. PM me if you would like their info. My car stops much quicker now. It was bone stock and only 46k miles, and wasn't bad, but I wanted better.
#19
Sorry.... I have been busy the past day and this is the first I have had a chance to get back with replies. First let me thank each and every one of you that responded. Lots of useful information. Decisions, decisions, decisions......
#20
Drifting
I have 100,000+ miles on my original rotors. When the hydraulic system is up,to factory specs, your brakes will amaze you how well they stop. Zora designed these brakes to stop a relatively heavy, high performance sports car. They did, they do.
Notice the calipers aren't original, they are stainless steel sleeved. Not seen is the braided stainless hoses that make a huge difference in pedal firmness.
Use the rotor money to improve other parts of your Corvette.
Pete
Notice the calipers aren't original, they are stainless steel sleeved. Not seen is the braided stainless hoses that make a huge difference in pedal firmness.
Use the rotor money to improve other parts of your Corvette.
Pete