How do you release the serpentine belt from the alternator in an f250 diesel 6.0?

Here's how to get a serpentine belt on or off (You'll need to do both). It's easy and doesn't require a prybar.


On:

• Get a 14mm or 9/16" socket and a long handled ratchet or breaker bar.
• Get the belt around all the pulleys except the A/C compressor or Alternator.
• Locate the tensioner pulley. It's one of the smaller ones and is mounted on a spring loaded arm. It's job, as the name suggests, is to keep the belt tight. Get your socket on the center nut of this pulley.
• Slowly pull the ratchet toward the center of the engine. The pulley will pivot on the arm allowing you to get the belt on the final pulley.
  
• Slowly release the tension.
  
• You're done

• Get a 14mm or 9/16" socket and a long handled ratchet or breaker bar.
• Locate the tensioner pulley. It's one of the smaller ones and is mounted on a spring loaded arm. It's job, as the name suggests, is to keep the belt tight. Get your socket on the center nut of this pulley.
• Slowly pull the ratchet toward the center of the engine. The pulley will pivot on the arm allowing you to get the belt off one of the pulley's (A/C or Alternator is best)
  
• Slowly release the tension.
  
• You're done

The belt tensioner is on the passenger side and is spring loaded it may feel as if it doesnt want to move it is very stiff alot of spring presssure you may need another set of hands to remove old belt be sure to observe belt routing so there are no concerns reinstalling new belt