freightliner flatbed no PTO out of the blue

I was doing electrical work on a towing flatbed, all my work is isolated to the rear of the vehicle. yesterday i started it, turned on PTO (got some grinding so had to flip it on/off a couple times) got the bed pushed up and up, then shut off the truck and turned off pto.
i started the truck a few times with pto off from then till now.

2004

today i started truck and engaged PTO, heard some brief engagment attempt and then air blow off. i flipped it on and off a couple times as i did yesterday but nothing.
going under the truck i found... a line blown off with two 10mm bolts shot out (not stripped) as if they were just sitting in there, how the hell this thing ever worked i have no idea...
i reinstalled this blown line but still have no PTO for the bed, i do not have much experience at all with PTO systems and need some advice here.

picture of what i found blown off:

... no pto??

edit, further testing is showing a rapid air loss on tank 2 when PTO engaged. im alone so its hard to diag this but it looks as if the air is escaping from the blow off vave on top of the tail housing

edit2: confirmed 12v to solenoid w/pto switch

3rd edit: im having a hard time envisioning a situation where that air line was on enough to allow the bed to work yesterday but blow off today... is a scenario possible where that was a reverse pressure line? so the actuator moved to engage the PTO yesterday but got pushed beyond its bore and is now stuck? so as to no longer allow the actuation?