FIRES MULTIPLE NAILS WHEN AIR IS HOOKED UP.

Air leaking from trigger when attempting to fire the gun is normal and should cause nailer to fire, however if the trigger pin is not depressed all the way in,the gun may not respond. Easy test. Remove the nails and remove the trigger. Connect the gun to air and quickly depress the valve pin all the way in with finger. If the gun fires, adjust the safety foot so that the trigger pin is depressed all the way in. If the gun still does not fire, then remove the head cap and pull out the headvalve. Apply plenty of white grease to orings and retest. If the gun fires, then replace the headvalve orings. When the headvalve orings are worn, air will leak from bulkhead chamber to the headvalve chamber causing the gun to not respond to the trigger. The addition of grease to worn orings will make them temporarily seal. Good luck

Most likely stuck trigger valve. Easy to check. Remove nails, remove trigger to expose the firing pin of trigger valve. Connect air and very quickly depress the firing pin all the way in. If the gun fires , adjust the safety to depress the trigger valve completely. If the gun does not fire, replace firing valve, or remove and check /lube o-rings in valve. Good luck

Could be just a lack of lubrication in the headvalve /orings or the safety foot is not pushing in the trigger pin all the way. Easy to check. Remove the head and pull out the head-valve. Apply plenty of white grease or silicone paste to the orings and the surface where the orings make contact. Install the head and test. If the gun fires then you are done. If the gun does not fire, make sure that the safety foot is depressing the trigger valve all the way in when attempting to nail. Simple test is to remove the trigger exposing the firing pin. With nails removed and air connected, with quick motion depress the firing pin all the way in. If the gun fires make adjustments to safety foot. If the gun still does not fire (with headvalve lubed) replace the firing valve core part # ca0108. Good luck

This problem occurs when the orings in the headvalve and/or trigger valve are worn or just needs lubrication. This also happens when the safety foot does not push the trigger valve all the way in. Easy test. Remove nails and air pressure. Remove the trigger exposing the firing pin on the trigger valve. Connect air and with a very quick motion, depress the firing pin all the way in. If the gun fires adjust the safety foot. If the gun does not fire, remove the head and pull out the head valve. Lube orings in head with plenty of white grease. Reinstall head and test. If the gun fires, time for oring kit or just keep applying grease. If the gun still does not fire, most likely problem is trigger valve orings. Good luck

Most nailers have a two position setting on the trigger to allow for single fire or bump fire. If set on bump fire, the gun will work better when you bump fire the gun instead of placing the gun on the work then depress trigger. Bump fire works best when safety spring has good tension. Easy test. Make sure that the safety spring is in place (with air hose removed, contact foot should spring back quickly when pushed against work). With air connected, hold trigger and quickly bounce the gun against the work. If the gun does not fire when you bump, the trigger is most likely set to single fire. With trigger set to single fire, you must place the gun against the work, then depress trigger. If the gun shoots two nails while set to single fire, most likely worn trigger or worn out trigger valve. These parts are not expensive and are easy to replace. Good luck

If the trigger is set to single fire, you will need to place the gun against the work then pull trigger as you have done. Try setting the trigger to bump fire and try again. If hear a thump inside the gun, remove the head and check that the head valve in not stuck from lack of lubrication. Easy test, remove the nails, remove trigger pin, remove trigger and manually push trigger firing valve. If the gun fires then suspect faulty trigger or safety arm not lifting enought to activate the trigger valve. Good luck

If no air is leaking from the gun, take out the nails, remove trigger by removing 3mm hex head bolt to expose the trigger pin. With air connected and side door open so that you can see the feeder, quickly depress the trigger pin with finger. Gun should fire. If gun does not fire (only makes air sound at trigger) dissconnect airline, remove head and lube headvalve with white grease and reinstall. Test again. If ok replace trigger. If still no joy, replace trigger valve with new factory or generic (part # TVA6). If gun fires but does not activate the feeder claw, remove two 6mm hex bolts from front of gun and split apart upper and lower body and check white oring (part # 149885) Good luck

May occur when headvalve or driver is stuck (will usually make a pop or click when tigger is depressed), or tigger valve has failed or safety not actually touching trigger firing pin. Easy test, remove nails, remove trigger by pushing out 3mm roll pin or bolt to expose the firing pin. Pull back nail feeder and place the nose against piece of wood ~ depress trigger with very quick motion with finger. If it fires, reinstall trigger and adjust safety foot so that the firing pin is pushed all the way in. If does not fire, replace trigger valve (usually tva6) or remove trigger valve and replace the 3 orings on the inner plunger. If you hear a pop or click when you do test above, remove head and lube the headvalve orings with white grease or silicone paste.

Remove nails and remove trigger to expose trigger valve pin. Place nose of gun against rubber pad or old coiled up air hose to absorb impact of driver and with very quick and deliberate motion press in trigger pin. If gun fires, then problem is with safety foot not pushing trigger pin all the way in (or worn trigger). Make adjustment as needed or replace faulty parts. If gun still does not fire, then likely problem is with headvalve. If headvalve orings are leaking, gun will not fire. Test for leaking orings as follows. Remove head and remove headvalve, apply silicone paste lube (plenty) to all orings and where orings contact. Assemble and do test above. If gun fires then surface where orings contact is allowing air to leak(smooth with very fine sandpaper if scratched).

There is one main part that can be the cause of the problem.

The trigger. Check to see if there is anything out of the ordinary with this. There should be some moving components attached to the trigger itself. Is any part of the trigger touching the button in the body of the gun when safety is not depressed. If the lever on the trigger is pushing on the button, even a little bit, It will allow the gun to fire again and again.