Couple of months ago I let someone take my beloved "Velma" for a test drive because he was interested in buying her. Twenty minutes later he returned her with a stuck left front caliper and smoking disc (Girlings, solid disc). The caliper pistons were stuck. Next day after cooldown I was able to remove the brake pads so the wheel would turn.

I drove her about 1/2 mile (using handbrake) to a local (non-Volvo) mechanic to put the brakes in working order. First he replaced the caliper and bled the brakes but couldn't get hydraulic pressure restored to the brake pedal. Next he replaced the master cylinder and reservoir and check valve to the vacuum booster. Same problem remainded--no hydraulic pressure in the system. Lastly he replaced the vacuum booster with one I got from the salvage yard. Still same problem. He's stumped and so am I. I brought her home today and she's sitting in my front drive. The brake pedal goes all the way to the floorboard. Hopefully we are overlooking something obvious. All vacuum hoses and fittings seem sound. Would appreciate any suggestions.