The staples will not come out of the device. there is the pressure to fire it out but the staples will not come out

Check for a broken piece of a staple jamming it.

did you look for a clog in the air passage inside the gun when you took it apart?

Disassemble and look for staple jammed in it.

My T50 would fire ONE 1/4" staple correctly and then jam, eating 3 or 4 and after digging those out do it all again. This was one staple eating machine!!.. I disassembled the thing, making some mechanical adjustments which allow only enough room for smooth feeding of ONE staple at a time and now it NEVER misfires or jams. These adjustments will take careful thought and filing of the end of the staple tray nearest the firing pin, along with slight bending of the firing pin to lay flat again the outside head cover. I also filed the outside "tips" of the firing pin to be absolutely flat where it contacts the staple. DO NOT shorten the firing pin if possible. Now I can get even 9/16" staples to go all the way in. :)

Check for jammed staple, you have to remove the screws that retain the head of the stapler. If air is leaking then there is a bad seal at the trigger.

There is a clip at the lower rear of the stapler--lift this clip upwards which releases the staple tension device which is the clip, a rod, a long spring, and a 'U' shaped clip on the far end. Pull this device all the way out, insert one length of staples into the slot that is revealed, then reinsert the tension device until the small clip re-locks at the rear of the stapler frame. One staple ejects per squeeze of the firing lever--hold the nose of the stapler firmly to the material to allow penetration of the staple. Hope this helps!

Remove the magazine and shake out all excess water from the tool. WD-40 is merely for Water Displacement, hence the name WD-40. You need to lubricate with shop grade oil. Inspect the driver head to make sure the surface is flat and free of dings or nicks. In order for your tool to work properly it needs to be able to feed without interruption, and the driver head needs to be able to move back to **** and forward to fire without hinderance. After insuring that all parts are in proper working order, reassemble, load, and fire. This should fix your problem 90% of the time. If not, then check the magazine spring to make sure it is delivering a strong drive to the loaded staples or nails, if not, you need to either use more of either to put more pressure on the spring, or you need to replace the spring all together.

Make sure the staples you are using are compatable with your gun they should be type 53 or JT21 staples and they are not longer tham the gun is capable of taking I think the maximum capacity for this gun is 5/16 or 8mm.
Turn the gun upside down and pull back the carriage, the staples are laid in the empty chamber in the gun itself not on the carriage points facing in the direction they fire ie points facing you .
Push back the carriage this should slide over the strip of staples until the carriage clicks shut.
You should now be ready to fire, try and keep pressure down on the gun as the recoil can make the gun bounce and you will leave the staples proud.
Hope this helps.

They all leak a little on firing. Is it a big blast of air or just a hiss? All guns have a 'safety' device that keeps them from firing unless you follow a set pattern. You must push the gun down where you intend to put the staple which releases the safety before you pulll the trigger. You must then release the trigger move the stapler off the piece push it back down again before you can fire another staple. You can get (free) frrom the manufacture a rapid fire shoe and trigger that allows you to hold down the trigger and bounce the stapler along your work shooting merrily away.

Fire the stapler with the load chamber open and down, see if anything falls out. Point it in different positions and fire it, just make sure it cannot fire anything at you.