That is a head scratcher getting different temp readings after swapping drums and using all different (new) parts. I would start by eliminating the pressure/volume issue. For pressure an 8oo# gauge with a 3/16 or 1/4 female inverted flare fitting adapter on the gauge port would work. For volume a helper and a graduated cylinder is needed. The line you removed to check pressure is left open and when the one working the pedal says "down" the other puts his finger over the end of the line till the pedal worker says "up". Repeat twice and the when you hear "up" hold the graduated cylinder in a position to catch ALL the fluid till the pedal man says "down". Fill master cylinder and get at least one more reading. Repeat on other side. If both pressure and volume are the same then I'm baffled and no help. If not check the v/p at any T-block or other fitting that could be restricting the flow to the RIGHT side. If not for the temperature difference one could suspect all the various front end components but this difference in temp pretty much restricts the problem to the brakes themselves. Please reveal the fix if it happens.
