Stanley Bostitch RN45B-1.

I bought this gun new, always lubed it with a few drops of pneumatic oil each use, and kept it clean. I've only done about 15 roofs with this gun ... minimal wear.

Then ... I put it in a box for 20 years in my detached garage. Temps here in Montana fluctuated between -30 to +105 degrees F. It worked perfectly before storage. Now ... it has 2 problems:

1 - leaking air constantly from trigger. Will I have to replace the entire trigger valve kit (TVA6), which costs about $20.00, or do you think it will be OK to replace only the o-rings on the trigger valve? I can get the trigger o-rings as a separate kit for $4.00.

2 - Skipping nails. It seems to skip every other nail or every third nail. What causes this?

3 - Does the Bostitch RBK13 rebuild kit include o-ring lubricant, or will I need to buy that separately?

4 - I found your video on rebuilding the Bostitch RN46 nailer. Is the RN45 very different? Will the RN46 video be ok for the RN45 nailer?

Thanks!!

Thank you for your thoughtful answer.

I ordered the RBK13 rebuild kit, and overhauled the entire head/cylinder assembly, plus the little nail advance cylinder on the side. I lubed everything with o-ring lube and a little oil during assembly. I put in a new trigger valve, and fired it up ... doesn't work.

When I pull the trigger, the gun doesn't cycle ... air just come pouring out of the trigger. I put in the old trigger valve and I get the same thing.

I took off the head again, and pushed the driver all the way down, put the head back on, and tried it again like that ... still didn't work. Then, I pushed the driver up a little (with the gun assembled) and still didn't work. I tried it with the driver in all positions, still wouldn't cycle.

I get the feeling that if I could just get the gun to fire once, it would "reset" itself and work fine after that.

Any ideas?

OK ... problem solved. I looked deeper into your Air Nailer forum, and found this thread:

forums.mastertoolrepair.com/index.php/fo...er-piston-won-t-fire

And just like in that other thread, I had installed the wrong outer o-ring on the head valve. Many of those o-rings in the rebuild kit look exactly the same. Also, when you pull off an old o-ring, it might be a little stretched out, which makes it harder to find which one is the proper replacement. It would be helpful if Stanley-Bostitch would label each o-ring in their rebuild kit with a part number and even where it goes, like: "MRG052526 -- Head valve outer o-ring".

So anyway ... my mistake was to put the head valve outer o-ring between the cylinder and the bulkhead, and put the cylinder-bulkhead o-ring on the outside of the head valve. After swapping them to correct the mistake, I put the metal head cap back on and everything works beautifully now. No more leaks, no more skipping nails.

For anybody who reads this in the future, the key thing is what the MTR admin said in his first response in the thread linked above: The o-ring on the outside of the head valve should be a LOOSE FIT. Find and use the one that fits loosely. Also, with the proper bulkhead o-ring installed on the cylinder, the cylinder will slide into the bulkhead much more easily.

I think later versions of the RN45 have two o-rings going around the outside of the head valve. That's a great idea, because when they loose their seal, the whole gun stops working. I wish mine had two.

Anyway, thanks for your help. Now my roofing nailer will be ready to do my roof in the spring.

Best of luck to all who read this.