It’s been awhile since I posted anything on my 420 project. Last time I was swapping in a 4 speed overdrive transmission in place of a 700r4 conversion. A kind member on this site did a trade. The overdrive accumulator piston had exploded which is why it didn’t bench check. With some modification of a readily available piston I got it repaired. I didn’t do anything but reseal both ends and top cover of the transmission. I wound up rebuilding the engine when I discovered head gasket weeping on the intake side from luckily minor corrosion.
Today I got it out for the first road test. Not finished but enough to get a test run in. The transmission worked well. A little growl in first for a split second and it shifts well and synchros seems to work well in all gears. I don’t have the electrics connected to the overdrive yet, so haven’t road tested that yet.
On the down side my brakes are giving me issues. The servo assembly isn’t releasing the pressure to the rear brakes. If I crack the line pressure releases and it rolls easily. If I apply the brakes several times they drag heavily. Does anyone have ideas on this problem? I hope I don’t have to fiddle with the servo a third time and have to bleed the rear brakes. It was pure he’ll last time.