Caliper Torque Spec Error (C2)

[Steve Vaughan]

In a recent rebuild of my rear calipers my inattention cost me an brake caliper. I disassembled my calipers cleaned and installed new seals then on reassembly looked up the torque specs on the caliper halfs retaining bolts in the 67 GM Chasis Service Manual, and after finally finding the torque specs in appendix mindlessly attempted to tightened to the spec'd 130 ftlbs while thinking that seems pretty high for a 7/16" bolt. I should have paid more attention,the printed spec is way too much for the 7/16" bolt atachment and I pulled the threads out the the caliper half.

I hope others do not make this same mistake. I am reminded again, just because it's print (or stated or emailed or...) don't make it true.

[Mike M.]

Re: Caliper Torque Spec Error (C2)

install a heli-coil and it'll be fine. mike

[Mike M.]

Re: Caliper Torque Spec Error (C2)

install a heli-coil and it'll be fine. mike

[Joe L.]

Re: Caliper Torque Spec Error (C2)

Steve-----

Yes, I'll bet this has screwed up more than a few folks. GM only provides the specs for the FRONT caliper bolts but they just say "caliper bolts". All Corvette caliper bolts are not the same size, though.

Anyway, the 130 lb-ft spec is for the front caliper bolts which are 9/16-18 bolts.

I've never found GM-published specs for the rear caliper bolts which are 7/16-20 bolts. I use a torque value of 65 lb-ft for the rear bolts. If GM had published a spec, I'll bet it would have been real close to that.

[Joe L.]

Re: Caliper Torque Spec Error (C2)

Steve-----

Yes, I'll bet this has screwed up more than a few folks. GM only provides the specs for the FRONT caliper bolts but they just say "caliper bolts". All Corvette caliper bolts are not the same size, though.

Anyway, the 130 lb-ft spec is for the front caliper bolts which are 9/16-18 bolts.

I've never found GM-published specs for the rear caliper bolts which are 7/16-20 bolts. I use a torque value of 65 lb-ft for the rear bolts. If GM had published a spec, I'll bet it would have been real close to that.