I'm doing the rear disk brakes on my 87 IROC. When I went to remove the rear lower control arm bolt to lower the control arm to get access to the lower caliper bolt, I didn't have correct size socket. 11/16 is too small and 3/4 is too big. Is this bolt really 23/32 in size. I have numerous socket sets and this size is not included. I also can't find this socket anywhere. Would a 18mm socket work? If so, I will have to purchase this since this size in also not included in a standard socket set. These rear brakes are a PIA.

 

Pretty sure it's 18mm.

 

It is 18mm.

 

General rule, everything on a thirdgen that doesn't thread into the engine, is metric.

 

Yup... for the most part, engine is SAE, chassis is metric.

Although, the old Saginaw brakes themselves, being OLD, are SAE. 5/16" Allen and such.

 

Did you really need to remove the LCA bolt to get to the caliper bolt?

 

Yes.

 

With the cast iron rear discs the control arm on one side is in the way. 89-up PBR discs are a walk in the park comparatively, with their 'quick change' pad design.