I replace the trigger valve and now it will cycle once and the ram won't return what should I look at next? If I disconnect the air and connect it again then it will shoot another staple.
Admittedly I have not worked on one of these in 20 years.
A lot of parts would suffer from dry rot.
I don't think the Head Valve is the issue...I think if it were the head valve it would leak all the time, or not fire at all and bleed air when the trigger pulled, but not the symptom described. Make sure all o-rings are lubricated well with o-ring lubricant.
My best guess would be sleeve A and Sleeve B, #‘s 22, 23 above the trigger stem (is this what you replaced?). I doubt it is the trigger stem itself.
Make sure the spring, # 24 is still there. Something is allowing the head valve to open, but not close.
