I have an 11/1974 FJ40 with an FJ60 disc brake conversion up front and I’m experiencing some intermittent brake drag on the front discs. The booster is a city racer for a 40 with a 40 series disc/drum master. Master is an O’reilly I believe. I didn’t do the conversion so I don’t know it as well. It’s also got a proportioning valve on it. The last time I was experiencing drag I opened the bleeder and the caliper released and you could spin the wheel freely. Drag occurs on both driver and pass sides so I’m thinking it’s something master related. No drag on the rear drums. Any ideas what could be causing the calipers to not be releasing? This is a sporadic deal and happens only sometimes so I’m looking for some outside help.