Just bought a 1993 F-350 7.5l with service bed Clutch is on the floor I hear this is common problem Is it clutch master or slave or should I just replace both .

 

I would fill the clutch master cylinder with brake fluid and pump the clutch pedal several times and see what happens. Yes, I realize you'll have to pull the pedal up also. The clutch master cylinder is just inboard from the brake master cylinder along the firewall. Don't forget to remove that rubber cup from the master cylinder after you screw the cap off and before you add brake fluid.

 

Make sure the clutch master cylinder is full of fluid. The fill is to the left of the brake master cylinder on the firewall.

That is the first thing to check and most common issue.

 

I agree on the fluid but also have a close look at the pedal linkage and at the firewall where everything is mounted.

 

I already tried fluid, and no luck still on floor !

 

Do you mean "it goes to the floor" or "it stays on the floor"?

Why start with the most expensive parts first?

Have you already checked the crossover shaft bushings, pushrod retainer clip and firewall as Lazy K suggested?

 

Goes to floor and stays there .Everything looks good bushings have min wear and everything is hooked up and mounted secure even put fluid in it and pumped several times stays on floor

 

If the fluid is staying in the reservoir and you've bled it, I'd say your M/C is toast...