live2plant
Member
Needing some help from experts on planter vacuum motor hydraulic fluid requirements from a 40 series tractor. I am preparing a 4640 for a 1770 planter and powering the vacuum fan with the third SCV in forward detent position, thus the retract port sends fluid out to the vacuum fan. The planter owner's manual indicates that for 40-60 series tractors, the pressure hose from the retract port of the SCV must be equipped with an inline flow control valve plugged into that retract port to adjust vacuum level. I am finding that no one at my JD dealer knows what part this is or why this is necessary so I went to another JD dealer and found a guy who seems sharp. He indicated that the way they would do it is to install an auxiliary return coupler kit to tap into the side of the SCV. I speculate they may have done it this way on the older planters when vacuum systems were newer thing. I purchased the kit and it seems something like a Power Beyond only without the Power Beyond block. So now we plug this pressure tip into that auxiliary coupler instead of the retract port of the SCV to power the vacuum fan and as I get it by doing so we do not even need the flow control valve though I am not clear as to why. To note, either way the returning fluid comes back to the extend port of the SCV. I understand a vacuum motor is high pressure and low flow and speculate that the need to retain a high pressure requires a reduction in flow and further if perhaps either method is a way of reducing flow about equally so as not to send an excessive pressure reducing volume to the motor which thus retains the needed high pressure. Your thoughts on this reasoning and if the auxiliary coupler system is a satisfactory method instead of a flow control valve would be appreciated.
Greg
Greg