I have a Bostich coil roofing nailer #RN46-1 leaking air at trigger area when depressed. Replaced trigger assy but same results. Anything else it could be?

Sounds like the head valve. Remove the head cap take out the head valve, clean, re-fit and give it a few drops of air line oil. Then give it a try. Good luck.

Leaking under trigger could be the ball seal part # 875645 if leak starts as soon as you connect the air hose. If no air leaks when you connect hose but begins to leak when you depress the trigger then replace the oring on the plunger which is part # 874820. If air leaks when you connect the hose and the ball mentioned above is good then most likely is leaking from oring # 876161 installed on cylinder plate (remove head and pull out the plate). Good luck.

Air leaking around the trigger area could be caused by vinyl ball / gasket under trigger valve bushing or orings within the gun. Easy test, remove nails and connect air (assuming that air is now leaking around the trigger area). Depressing the trigger stops the leak, replace vinyl ball. Depressing trigger does not stop leak, move plunger b (plunger B, small shaft under bubber bushing next to the trigger valve) with your finger in then out to determine if air leak changes tone. If air leak changes sound or tone, then air is leaking past orings of the cylinder guide and/or cylinder plate and/ or the cylinder itself is scratched by debris where the orings make contact. Pull out the cylinder and examine the contact areas. If scratched, use 300 grit paper to smooth, if smooth, however, suspect the orings of cylinder guide (or cylinder guide is cracked). The cylinder guide is difficult to remove and install without causing damage to guide or cutting new orings when installing. Do not remove the guide unless all the other options have been checked. One last bit if information, I have noticed that some guns will leak air if the orings on the feeder piston do not fit snuggly. Make sure that leaking sound is not coming from feeder area (remove the basket and feeder/feeder pin/spring and pull out the feed piston, making sure that the largest oring is making good contact within the cylinder). Good luck with repair.

Two areas to check when air leaks from around the trigger. Rubber ball under trigger pin will cause air to leak, however when good side of the ball falls on the seat, air will not leak for a while. If air is leaking from plunger pin (just in fromt of the trigger pin), remove the head and pull out the cylinder plate to reveal broken oring (oring part # 876161). Good luck with your repair project.

Your nailer uses a trigger valve (part # tva6 cost about $20) and is sold at www.bostitch.com or generic valves sold on ebay . If you have a source for orings, you could try to repair the valve. Remove the roll pin that holds the trigger to expose the tva6 valve. There are roll pin/pins that hold the valve in just above the valve in the body. Remove these pins and apply air pressure to gun to pop-out the valve. Use caution when you do this. Remove nails, lower pressure to gun and use glove or rag to catch valve because it could come out with force. With tva6 valve in hand remove two pins that hold valve together and remove inner plunger. The middle oring on plunger is cause of leak. Try using an oring about same size as the broken seat. It must fit pretty tight to work. If you had a small leak it could be that the firing pin orings fit too loose or just too worn. Use silicone lube or oring lube on the orings and the valve port. Good holidays.

There can be a number of reasons for this. A little more info is needed though (See below). This symptom can be due to a lack of lubrication, the plunger being stuck and not in the fully retracted position, etc.

1) Can you hear any air leaking anywhere?
2) Can you see the location of the plunger (drive pin)?
3) Is there any reaction to the trigger? WIth the trigger held, and hitting the roof, is there any air release or anything at all?

Thanks,
Dan

could be either that or a damaged o ring, when was the last time serviced, all o rings replaced?? could be that the tool needs a thorough cleaning and new one installed. it is not hard

Sounds like you need a repair kit or take to a tool company that installs the kit.

Where does the air leak out from? If it leaks from the trigger DeWalt makes a trigger valve assembly part # 641006-00 list 8.89 BUT if it leaks from other areas we have to look into it deeper. If it is just the trigger valve let me know and I will give you instructions how to remove and install the new one.