Thanks for the post!

Right, that Spring is what is causing the nailer not to fire as it's not actuating the trigger valve plunger (as you mentioned).

www.mastertoolrepair.com/pneumatic-frami...-n80cb-p-649621.html

Per the schematic diagram, is it the #90 Spring on the Contact Arm that you're not sure about?

I'll see if I can research this a bit and reply with some additional information for you.

- MTR

By the description I believe you may have the old style sequential Trigger that used the spring seated between the trigger and the valve body.

This spring makes sure the trigger is in the full down position before the trip lever is activated. If the trigger is up a bit, the trip bypasses the lever under the trigger and will not actuate the trigger valve stem. This is the safety feature of the “grey” sequential trigger.

Also, as a reminder, with sequential triggers one must push the tool down to the work surface first and then pull the trigger. If you try to actuate the trigger first, then bump the tool, it will not fire. I suspect this is possibly the issue.

You may need the spring to work faster, but it should actually cycle the tool without it if you use the proper “sequence” to fire.

If this does not help, it means the trigger itself may be faulty. Today we use a different style SEQ6.

Note: The spring shown is conical shaped, but the actual spring used for many years is not. We had conical shaped for a few years, but it was changed. I didn’t to confuse you by this old picture. I was hoping to take a picture, but I do not have any of these old style triggers around anymore!

- MTR

Glad to help! Feel free to post your results here as I'd like to know if that did the trick.

- MTR