[4GTOSplus]

I have been fortunate to own my 67 GTO for 45 years now. And again my 4 piston calipers are leaking. Have rebuilt them several times, new ones, rebuilt ones and so on. I will be going to the single piston set up. Question is do I need to replace the spindles? Or are they identical to later years. Thanks

[gto4ben]

The single piston brackets and hardware will mount to the four piston spindles. When I added the single piston setup to my '67 LeMans, I did a fit check of my four piston calipers and brackets..

With regards to your four piston caliper leaks, I performed these remedies to prevent leaks.

1. Polish the bores
I had my calipers stainless steel sleeved but they leaked after a year. I removed and cleaned them and took a suitable sized buffing wheel and stainless steel polishing compound to polish the bore to a mirror finish. I attached some before & after photos. You can see where the lip seal rubbed away in the bore.

2. Use DOT3 EPDM O-rings
McMaster Carr EPDM 011 o-rings are great. They are DOT3 compatible and are cost effective. The lip seals may be sourced from CSS or through those import distributors. Use McKay Brake Assembly Lube.

3. Rotor Surface parallelism & Wheel Bearing preload.
I verified the parallelism and followed the 67 Shop Manual's instruction to preload the wheel bearings. I bought a lb-in torque wrench to get the final reading.

[4GTOSplus]

Ben, Thanks for the info. I have done all that you have over the years. At this point im moving on to single piston.