I was looking around under my 4720 trying to understand how the hydraulics were all plumbed up. There is a valve block plumbed between the pump and the dual mid SCV's that I couldn't find on the JD parts breakdown. It has 2 wires coming out of it. What is that gizmo?
Also, After the dual mid SCV's the supply goes to the PB, then the 4th and 5th SCV's, then the 3rd EH SCV, then the rock shaft. I thought that was kind of odd, if you had the backhoe on, all of the hydraulics back there would be disabled. I guess you probably wouldn't be using them anyway. Maybe the 3rd loader function if you had a 4in 1 bucket or something like that. I have read here over and over about the PB tank port bypassing the rock shaft , but ALL of the rear hydraulics gets bypassed. Something to keep in mind if you have some odd application where you want those ports to be live with the hoe on. You would want to custom plumb your own setup.
Of course, it makes me wonder if the dealer plumbed it the way Deere intended. They had quite allot of trouble figuring out what lines they needed.
Another question. The 4th and 5th SCV block has a direct to tank line... the 3rd EH does not. Is that just for float operation?
Also, After the dual mid SCV's the supply goes to the PB, then the 4th and 5th SCV's, then the 3rd EH SCV, then the rock shaft. I thought that was kind of odd, if you had the backhoe on, all of the hydraulics back there would be disabled. I guess you probably wouldn't be using them anyway. Maybe the 3rd loader function if you had a 4in 1 bucket or something like that. I have read here over and over about the PB tank port bypassing the rock shaft , but ALL of the rear hydraulics gets bypassed. Something to keep in mind if you have some odd application where you want those ports to be live with the hoe on. You would want to custom plumb your own setup.
Of course, it makes me wonder if the dealer plumbed it the way Deere intended. They had quite allot of trouble figuring out what lines they needed.
Another question. The 4th and 5th SCV block has a direct to tank line... the 3rd EH does not. Is that just for float operation?