URQ brake master cylinder rebuild

[DGraber460 at aol.com]

Are there any special things to watch for, other than releasing the bomb 
pressure by pumping the pedal till hard, when rebuilding the brake MC on an 
URQ?
The tandem system is foreign to me, and I will be attacking it tonight, as 
today the rear portion transitioned from leaving drips to leaving puddles of 
ATF.
Another problem I've been having is the brake light has been on for months. 
The pressure switch on the side of the bomb valve reads continuity at all 
times. What should it read, and when? I'll check the lower (and very 
messy-see above) switch tonight. 
The bomb is only 6 months old.
The pedal test shows good (many pumps till hard).
The brake fluid reservoir switch works (fluid level to spec).
The E-brake handle switch works to spec.
Disconnecting and/or bridging any/all of these will not turn off the light, 
and all the brake lights work fine. 
TIA

Dennis