An easy job, until I tried to torque the upper caliper bolt on my 70 gs. Stripped. These are the threads in the bracket that holds the caliper to the knuckle. Any tricks or do I need to replace the bracket?
Should be able to repair with a Heli-coil. You will need to know the thread size and pitch to get the correct kit.
Thanks - that's what I was thinking. I see Dorman makes an Oversized Brake Caliper Bolt but that seems a bit sketchy. Also, anyone have experience with Time-Sert vs helicoil? Seems like a better solution except the cost.
Sounds like helicoils are a bad idea too? The Time-Sert threaded insert 7/16th 20 kit is $100. 4X the helicoil kit! The nice thing about the Time-sert is it can be put in backwards so it tightens against the flange, ie it will act like a nut.
You have to keep in mind that the threads in the flange are only about 1/4" deep making a Helicoil or some other type of threaded insert not have the strength of just the bracket. I myself have used the oversized bolt in the past with NO problems. Tom T.
Pipes - the caliper bolt holds the bushing that the caliper rides on. Can't be bigger unless the bushing ID is bigger. Tom - yes, I measured at .366 inch. Time-sert make them as small as .250 and have one that's .370. But with the flange counter sunk into the hole there will not be much left, maybe 2 or 3 threads. Interesting that you had no issues with the oversize bolt. Did you tap it first, or let the bolt cut the threads? Can you remove it later and re use it? Interesting reply from Time-sert: "Hello You know on this application you might be better off using a heilcoil because we don't have a stainless insert that length. You would want stainless for Brake caliper. Sorry we could not be of more help on this. Best Regards Time-Sert" Shows they care about customers!
Ha Ha - I found the missing thread - thought this was funny. The bearing came out with the bolt and was stuck to it. Here's why:
Another follow up - Just for fun I bought the oversize bolt and the instructions say: One time use - do not reuse Only one bolt of the two can be an oversize bolt Use as a temporary repair Hand tighten only - don't torque to OEM spec The oversize bolt is longer that the standard bolt as it has a cotter pin on the outside end. This keeps it in the caliper if it should come loose. So...only use when necessary!
Just an FYI........I had this same problem years ago on a '78 Z/28. I used a heli-coil and had zero issues with it for the 2 years or so that I owned the car.
Thanks Nick, that was my first thought - since I had to replace the rotor I went ahead and replaced the bracket.
