I have a set of rotors that Fran furnished to me way back when I was searching for high performance brakes for the C-4 front suspension. I have just had a few problems with that setup. On the second drive of the car, I noticed the brakes grabbing and releasing. It seemed to get worse with more braking force aplied. So I checked the suspension and found two problems. The first was that the spacers in the polyurethane bushings(new), that hold the lower A arms on were a sloppy fit. The bolts that held the A arms in place are metric, measuring .454 as best I can measure. Being a DRB I am wondering why they made these this way. Original brakes that came on the car were worn out corvette units that probably were sourced from a junk yard. Do they have Corvette junkers in Australia? Remember I bought this car second hand and it had never been driven. Anyway, the front bolt is a grade 9 metric fully threaded bolt with a radiused head and looks like a factory item as it has a built in washer on it. It looks likd a Corvette item. Source??? The back bolt is a metric grade 8, 5 1/2" bolt due to a frame member next to the housing for the suspension. This may need updating to a grade 9. The spacers in the polys are 3/4"OD and .502 ID for a standard 1/2" bolt which will not go into the frame members. Had I known this in the early build stage I could have had them converted to the American standard. But that was then and this is now.
What I did was to get some 3/4 inch stock and drill it out to .002" over the bolt size. That solved the sloppiness.
Now the brake issue. When I recieved the brake adapters and rotors/calipers from Fran there was a slight problem. In shipping the box got dropped and the hub(s) were dented(only thing I could see that was amiss). By dented there were marks on the hub(s) that looked like someone had hit them with a hammer a time or two. I informed Fran at that point to see what should be done. We figured this was cosmetic and to leave well enough alone. It would never be seen and therefore would be more trouble than it was worth to persue anything further. Fran was very generous to help me out. He even sent the taps and dyes needed to install the components. All was assembled and torqued at that point. Move forward a couple of years. I pulled the calipers and checked the rotors for eveness and found the right front rotor had a very slight warp outward over about 20-30º of the face of the rotor. I took the hub off and repositioned the rotor on the hub and retorqued it to see if it was the hub. It made no difference, as I marked the rotor and it came up the same. I took it to Pep Boys to get it turned to true it up. They informed me that they could not turn the rotor as it was in their works a "throw away rotor" and for safety reasons they could not allow me to have that done and reinstalled on the car from a liability standpoint. Thier words, the rotor was wide and its face, thin with large internal fins for heat disipation(read high performance), and it probably would chatter even if they did it.
My question is should I try to reface this still new rotor the slight facing needed to get it true. I don't think it is more tha a few thousands at most. Or should I bite the bullet and get a new rotor?
Bill
What I did was to get some 3/4 inch stock and drill it out to .002" over the bolt size. That solved the sloppiness.
Now the brake issue. When I recieved the brake adapters and rotors/calipers from Fran there was a slight problem. In shipping the box got dropped and the hub(s) were dented(only thing I could see that was amiss). By dented there were marks on the hub(s) that looked like someone had hit them with a hammer a time or two. I informed Fran at that point to see what should be done. We figured this was cosmetic and to leave well enough alone. It would never be seen and therefore would be more trouble than it was worth to persue anything further. Fran was very generous to help me out. He even sent the taps and dyes needed to install the components. All was assembled and torqued at that point. Move forward a couple of years. I pulled the calipers and checked the rotors for eveness and found the right front rotor had a very slight warp outward over about 20-30º of the face of the rotor. I took the hub off and repositioned the rotor on the hub and retorqued it to see if it was the hub. It made no difference, as I marked the rotor and it came up the same. I took it to Pep Boys to get it turned to true it up. They informed me that they could not turn the rotor as it was in their works a "throw away rotor" and for safety reasons they could not allow me to have that done and reinstalled on the car from a liability standpoint. Thier words, the rotor was wide and its face, thin with large internal fins for heat disipation(read high performance), and it probably would chatter even if they did it.
My question is should I try to reface this still new rotor the slight facing needed to get it true. I don't think it is more tha a few thousands at most. Or should I bite the bullet and get a new rotor?
Bill