short cycle on system

I have a well system. The pump is a red lion. the pressure tank is a bladder less tank

here is what is going on.

the system short cycles constantly when I run the water. if I keep running it I lose water totally and have to shut the pump off as it gets hot.
after 15 minutes or so I turn the power on again to the pump and it runs until I get pressure again
the pressure drops while cycling but as soon as the pump stops it returns to almost 40 lbs.
I do not hear any water trickling at the tank while this all is going on or after I shut the pump off.
I have tried bleeding the air off and recharging the system but it starts to short cycle again with in hours.

could it be the pressure regulator?
I don’t think it is the pump as its only 3 years old.
I also don’t think its the tank as if I don’t run the water it wont kick in like it has a leak.
my gut says its the pressure regulator?
thanks