Did you air it up with the clamshell apart can you feel the leak coming from it? If the noid is good then the barb isn't sealing or the hose has a hole in it.
As stated above its most Likely a ram oring.
Or another one if the barbs or hoses
The noid is probably one of the most dependable parts when it comes to wear in the old timmies as long as you don't pop it by over pressurizing it, it should last for a long time
TopGun GSP (Garden State Pump)
Theres no me in suck but there is always u