Raise the front end off the ground and turn both wheels by hand. If one turns easier than the other, you have either a sticking calper slide or a sticking caliper piston.
You may also have an internal brake hose failure. If you suspect this and the wheel is very hard to turn, open the bleed screw and it will release the hydraulic pressure on the piston.
A car this age should have been repaired with loaded calipers.