Both Rear Brakes Sticking Holding

[dscottp]

Hey folks,
I just bought my first vette, a 99 convertable. About 100K miles. One of the rear rotors was cracked so I replaced both rear rotors and pads. I also greased up the caliper pins and they move freely. The issue is once I drive the car a few miles it feels like the brakes are being applied. The car would hold on a hill and wont move in gear (Auto) at idle. If I jack the car up there is quite a bit of friction on the rotors that goes away after awhile and then they turn freely again. I havent been able to duplicate the condition on jack stands. I can get them hot but they remain free wheeling. This is both wheels so it doesnt seem like a caliper or a brake line. I used a temp gun on the rotors after a short drive and the fronts were around 400 degrees and the rears were in the 220 range.
For what it is worth, I am a pretty good mechanic (as a hobby) but this baffled me. I am wide open to ideas and yes, i have been searching the forum! I appreciate your thoughts and look forward to being part of this community!

 

[LLC5]

Hey folks,
I just bought my first vette, a 99 convertable. About 100K miles. One of the rear rotors was cracked so I replaced both rear rotors and pads. I also greased up the caliper pins and they move freely. The issue is once I drive the car a few miles it feels like the brakes are being applied. The car would hold on a hill and wont move in gear (Auto) at idle. If I jack the car up there is quite a bit of friction on the rotors that goes away after awhile and then they turn freely again. I havent been able to duplicate the condition on jack stands. I can get them hot but they remain free wheeling. This is both wheels so it doesnt seem like a caliper or a brake line. I used a temp gun on the rotors after a short drive and the fronts were around 400 degrees and the rears were in the 220 range.
For what it is worth, I am a pretty good mechanic (as a hobby) but this baffled me. I am wide open to ideas and yes, i have been searching the forum! I appreciate your thoughts and look forward to being part of this community!

If the brakes were working good before the rotors and pads, then it could be that the parking brake shoes are adjusted too tight.

 

[dscottp]

Thanks for the input. The brakes were dragging when I bought the car. I was hoping it would be caliper pin corrosion but it seems not. Iunless I have duplicate problems on both sides, I would guess it is upstream of the calipers. The hand brake is adjusted properly to the new rotors, even a little loose. This seems to rear it's ugly head after a bit of a drive, maybe a couple miles....