Need to make a clutch adjustment on 1991 Mazda B220 pickup

The clutch pedal can be adjusted inside the truck under the dash. You need a 10mm and a 12mm open wrenches to make the adjustments.there is a 3-4 inch threaded rod that you loosen the 12mm lock nut then you can turn the rod with your fingers or the 10mm wrench. Turn the rod so it gets longer toward in the direction of the engine. then start the truck and check how the clutch feels. when it feels right then tighten up the 12mm lock nut. If this does not solve the problem then you may need a new clutch.

Check the fluid, check for leaks, if there is replace the cylinder or hose and bleed the lines of any air. There a two cylinders, the master cylinder(on the fire wall not far from the brake cylinder) and the slave cylinder(on the gearbox) i think this maybe your problem.