I have a 94 Fsuperduty with a flatbed and lift that folds up and stores under the end of the bed. Recently while on a job the lift wouldn't go up, so I checked the one fuse I know of in the system and it was burnt. Put a new one in and before the lift reached the top it burnt-out again. It had been working with no problems for months prior to then.

 

What brand and model number is the lift?

 

It's an old waltco 221.

 

Is there a way to rebuild or overhaul the pump it looks kind of beat down.

 

Looks like you can still parts. Here's a parts list.

http://waltco.wpengine.com/wp-conten...015-REV-06.pdf

Here's a website.

Liftgates for Trucks - Manufacturer of Hydraulic Liftgates

The way these things usually work, they are hydraulic power up, gravity down. The pump sends hydraulic fluid out past a check valve and into the cylinder to lift it up. For down the pump is not running, they usually have a solenoid valve that lets the fluid go around the check valve and back into the reservoir.

Makes sense you have a pump problem if it blows the fuse going up, since that is the only time the pump runs. I would look at the commutator and the brushes in the motor, and also the bearings.