So, I've had my rear calipers out of the car three times now, and it's always been a brutal experience getting the caliper mounting bolts out. Just turning them has been a 30 to 40 ft-lb torque exercise.
I always blamed this on the bolts. The factory pair were blue (always a bad sign) and they were miserable to get out. So, I bought a new set of bolts from the parts department and used them. They came with thread locker on them and they were worse! They were so hard to install that I actually hit target torque before they were all the way in. The caliper was rattling so I tightened them some more.
So, over the winter I invested in some bolts from Belmetric. 10.9 rated with the correct dimensions and no thread locker. I figured I had it beat. But, today when I pulled the calipers off to install the CCB rear rotors, I found that even the new uncoated bolts wouldn't screw into the caliper threads. So, I took my trusty M12x1.75 tap and chased the threads. Well, it wasn't really "chasing" them. It might as well have been "making" them. Even with lots of Tap Magic, it was tough going (and this is aluminum) but I got the tap through. There was a mess of thread locker and metal chips, but when i was done, I could finally screw the bolts in with no problem.
So, the question is, has anyone else experienced this? Are my rear calipers mis-manufactured or do they really have distorted threads to keep the bolts from backing out. I've never seen anything like it.
I always blamed this on the bolts. The factory pair were blue (always a bad sign) and they were miserable to get out. So, I bought a new set of bolts from the parts department and used them. They came with thread locker on them and they were worse! They were so hard to install that I actually hit target torque before they were all the way in. The caliper was rattling so I tightened them some more.
So, over the winter I invested in some bolts from Belmetric. 10.9 rated with the correct dimensions and no thread locker. I figured I had it beat. But, today when I pulled the calipers off to install the CCB rear rotors, I found that even the new uncoated bolts wouldn't screw into the caliper threads. So, I took my trusty M12x1.75 tap and chased the threads. Well, it wasn't really "chasing" them. It might as well have been "making" them. Even with lots of Tap Magic, it was tough going (and this is aluminum) but I got the tap through. There was a mess of thread locker and metal chips, but when i was done, I could finally screw the bolts in with no problem.
So, the question is, has anyone else experienced this? Are my rear calipers mis-manufactured or do they really have distorted threads to keep the bolts from backing out. I've never seen anything like it.