16245 pto

Hey guys,
I just bough a 16245 and had pto problems, pto would run fine on tmr mixer for about 15 min and then shut off and could not start it again, I have changed the pto clutches and all O rigs. I also took part the pto and hi/low valve under the floor, everything looks normal. I had a gadge on the back hydro line that goes into the pto casing, my gadge only went up to 100 psi but when I acctivated the pto the gadge went all the way around. So if any one knows what's doing on please help .

Might seem silly but you haven't knocked the PTO selector out of position beside the seat? To the right of the seat next to the handbrake is a small leaver that selects between 540 and ground drive and neutral.