72 Imperial - ran great from 1993 to 2001 and then I put it in dry storage to travel for work.
Fast forward 11 years.
I trailer it to the house and up on jack stands it goes for new leaf springs, new tank, new sending unit, new fuel lines, new carb.
Test drive around the block and I notice it feels like its dragging when I stop accelerating. I pull it in to the garage and hear the front tires squealing and a screeching. Mostly the right.
Pull off tires and try to recess puck on right caliper. FROZEN. Going no where.
Peek in master cylinder and front chamber is clear - you can see to the bottom. Back chamber looks like coffee.
I remove the right caliper with hammer assist and unscrew rubber brake line. No gravity flow.
I replace master cylinder cover and pump pedal. No flow.
I start car and pump pedal twice; I get a marginal amount of fluid in my drip pan.
I remove the left side caliper and unscrew from rubber brake line. Gravity drip to the tune of about 3 drops per second, and still no flow from right line.

Master cylinder was replaced by me in 1995 and the brakes worked fine all the way til I parked it in 2001.

How do I check the no-flow condition on the right side? Break the line at the rubber-to-steel junction?

Could it have developed blockage in the proportioning valve?

Master cylinder?

The rubber brake line?

What say you?