something must be lose,

 

Are you talking about the hydraulic connections? Need more info

 

If its electrical,check the tractor's ground wire ends

 

The first 8-15 bales are perfect, then the pressure drops dramatically. Have replaced the pressure transducer and scylinoids, scylinoid magnets and stems. Still not baling right.

 

The monitor is showing : C inc pressure.

 

Monitor is warning that it's not seeing an appropriate increase in pressure after an attempt. I think it triggers if pressure fails to raise by 50 psi after a number of attempts (not sure if that's 50 psi per attempt or overall). It could be a valve block problem, but otherwise it's normally an indication that the tractor isn't providing enough pressure or any at all.

Is the baler configured as a Closed Center or Open Center? This is a closed-center load-sensing tractor; I believe there is a load-sensing kit for Hesston balers, but maybe not the 4900 specifically. May need to adapt a kit off another model. Unfortunately I can't get any parts books to open right now to know for sure.

 

when ever the monitor is unplugged from the baler, or a power loss occurs the baler goes to the closed center hyd. setting.. I think ( but don't for sure ) your NH tractor is open center so you have to make sure you program it back in to your monitor. or you will be damaging your baler... or like was posted above ... check your power source and your ground for your power if you have every thing hooked up right and programmed right and had a actual hyd pressure issue you should get a Error code of #9

 

Sounds like this is the first time this baler has been on this tractor so it's an assumption it is open center. That said, no harm will come from setting the monitor to open center if the baler is closed other than a missing solenoid alarm. To do the other way around, however... yeah, bad news.

That said: http://www.tractordata.com/farm-tractors/000/6/5/652-ford-8970.html

Should be a closed center tractor.

Edit: Finally got a parts book to open. There is a load-sensing kit for the 4910 balers which is an additional solenoid valve that plumbs the pressure side of the valve block to the tractor. I think it wires into the closed-center solenoid circuit, but can't recall for sure. Chances are it can be made to work on the 4900.

 

first question. do you have an operators manual. this whole hyd set up is explained in front of manual. i if you don't have one pm me and i'll fax it to you. also if you don't have one i would get one, iv'e had a 4900 for six years it still throws things at me that i need the manual for.