[R3ctivision]

Hi all,

Going to try changing the rotors on my ZLE on Sunday. Here are the caliper bolts I ordered (I understand they are one time use):

4x 11570092
4x 11570091

I forget which part number is for front calipers and which is for rear calipers.

Can anyone confirm what the torque specs are for these, and whether I need to add any locktite, etc? Are they safe to loosen with an impact wrench, and just use a torque wrench to tighten?

Thanks!

[h018871]

This info is for a 2020, I think they are the same.
the bolts are NOT single use items, I plan to use new ones after 3-5 uses
They thread into aluminum knuckles, so IMO it is best to remove manually rather than using an impact

Front Caliper Bolt GM 11570092
First Pass: 150 Nm (111 lb ft)
Final Pass: 15-30 degrees

Rear Caliper Bolt GM 11570091
125 Nm (92 lb ft)

One more thing from the manual
Caliper torque procedure:
Thoroughly clean the residue from the bolt threads with denatured
alcohol or equivalent and allow to dry.
Thoroughly clean the residue from the threaded holes with denatured
alcohol or equivalent and allow to dry.
Apply threadlocker to 2/3 of the threaded length of the bolts.
GM 89021297 (RED)
Ensure there are no gaps in the threadlocker along the length of
the filled area of the bolts.
Allow the threadlocker to cure approximately 10 minutes before installation.

[R3ctivision]

Wow, glad I asked. Thanks for the details!!

[h018871]

[R3ctivision]

Update: I barely managed to achieve 111 ft-lbs and couldn't get the extra 15-30 degree turn. Very little room to maneuver a 2 ft wrench when the car is lifted on a floor jack.

Anyone think that's ok and safe even for track use or should I get it on a lift where there is more clearance to force it a bit further?

Also, I really underestimated how much of a pain that little rotor retaining bolt would be. It consumed most of my time. It had been over tightened and I stripped it when trying to loosen. Tried some bolt extractor kit which failed. Only got it out after drilling, hammering the crap of a T30 bit into the bigger hole (normally T25 I think?) and then hit that hammered bit with an impact. I threw away that little bolt, doesn't seem necessary anyway once the wheel is mounted.

[Crushed 1LE]

Tighten until you hear the fastener snap, then back off half a turn

[R3ctivision]

Ok here's a couple tips for idiots like me that don't think..

(1) Get both fronts in the air, get wheels off, then turn the steering. Gives you enough space to get a breaker bar or torque wrench to the caliper bolts!

(2) Never over tighten the rotor screws. Use anti seize on them. They're just there to stabilize the rotor when the wheel is off. If they are on tight and not stripped try using an impact to get them off, not a hand tool. If you use a hand tool you'll just spin the rotor and also probably strip the bolt head and make it worse.

My second rotor took me an hour once I realized these two tricks. First rotor was multiple hours..

[TheRealJA105]

Originally Posted by R3ctivision

Ok here's a couple tips for idiots like me that don't think..

(1) Get both fronts in the air, get wheels off, then turn the steering. Gives you enough space to get a breaker bar or torque wrench to the caliper bolts!

(2) Never over tighten the rotor screws. Use anti seize on them. They're just there to stabilize the rotor when the wheel is off. If they are on tight and not stripped try using an impact to get them off, not a hand tool. If you use a hand tool you'll just spin the rotor and also probably strip the bolt head and make it worse.

My second rotor took me an hour once I realized these two tricks. First rotor was multiple hours..

Excellent tips! I also learned the hard way many many years ago about the rotor retaining screws. Now it is always lots of never seize and just barely tight!