- Mar 18, 2008
- Cedar City, UT
- '90 Saab SPG, '84 K5 Blazer, '67 Fairlane 500
Maybe I missed it, but did you change your proportioning valve when you went to rear discs? If you've still got a disc/drum proportioning/combination valve installed, it'll never send enough volume to the rear to make the discs work. You need a disc/disc valve or (even better) an adjustable one.
That's not to say you don't still have some air in there somewhere, but it may be compounding your problems.
If that image is accurate and no changes were made after it was taken, your rear calipers are installed backwards (driver's side caliper on passenger side and vice versa). Bleed screws need to be on top to get the air out, in this pic the caliper on the divers side is a passenger-side caliper as you can see the bleed screw is on the bottom side of the piston housing - they will never bleed correctly like that. You can just see where the bleed screw should be on the passenger side caliper as well, and since it's not there I can safely say the calipers are just swapped rather than you having two passenger-side calipers installed.
The proportioning valve is an adjustable one, also from Wilwood, that was installed about a year ago.
There were no changes to the master or the proportioning valve for the swap, but the master has no residual valve, so it is good for a disk/disk setup.
There was also no residual valve in the system for the rear drums, so they probably were not working right
Either way, good spot on the calipers; they were indeed not changed since that picture. There was a reddit post on Tuesday that I saw not long after my post here that clued me in, and I went out and checked:
The calipers are indeed upside down
Its going to be fixed this weekend. I was going to post up about it after I had fixed it, but you beat me to it