Hello 1572013,

We have an article and video on How to Install a Driver Maintenance Kit on a Porter Cable Nail Gun. I hope this will end your frustration.

-WJA

Hi jagraybill,
You will need to replace the head valve o-rings. Whats happening is when you pull the trigger the head valve should snap up but because the o-rings are worn in the head valve the valve gets slightly cocked in the head cap.When you hold the trigger and connect the hose the head valve gets jolted and drop back down on the cylinder.Replace the o-rings and you should be fine.Hope that helps.Good luck.
Tinker

Hello binar,

In answer to your question. The part number 894742 are sold individually and are not sold in a pack.

-WJA

Hi Fire8033,
There's a couple of things to check on this tool . Take the nails out of the tool then place the nose of the tool on a board and press down and engage the safety while pulling the trigger.While your doing this connect and disconnect the air hose a couple of times and see if the tool starts working.What this does is check to see if the head valve is cock in the head and not being allowed to move in the head.If that won't help take a small screw driver and slide it between the trigger and trigger valve and see if the tool can be fired manually.This checks for bent or worn linkage on the trip arm. If it still won't work remove the head and with a wood dowel or other soft object see if you can move the piston up and down the cylinder.This checks for any nail or part of the nail shank being stuck in the channel of the magazine blocking the cycling of the driver. One of these things should be your problem.Hope that helps.Good luck.
Tinker

Thank you for the reply, I will try this today when I get home.