When you say it "locks up", is it a sudden grab? Is it just a pull on the steering wheel or does it leave a black mark on the pavement? And does it let go when you take your foot off the pedal?
Is the driver's side even working?
Are both sides adjusted the same?
The lack of hydraulic "feel" on the right side is compelling, but I'm not sure that air in a wheel cylinder would cause such a condition.
I've seen bad hoses cause some odd problems, but usually they act like a check valve, and don't allow the brakes to release when there's no pedal pressure...at least on discs.
It's generally good to try to figure out a problem before just throwing parts at it. Fortunately, I think these brake systems are relatively simple and replacement parts are inexpensive.
Best luck, and keep us posted.
cm
