Fruita CO | Gerald J. - 12/23/2014 07:58
For ordinary hydraulic cylinder operations it should run for hours with the clutch pedal pushed. All the front reservoir needs to supply is the difference in the cylinder volume on the two sides, so when extending it takes oil from the reservoir, but when retracting it puts oil back in the reservoir UNLESS the valve return is plumbed to the transmission sump instead of the return to the SCV or the transmission oil filter. The front reservoir has several gallons of oil stored at about 250 psi,. On the early new generation tractors returning oil to the transmission case means the available flow is limited by the charge pump, which is smaller than the main pump, not the flow of the main pump. That's not the right way to use the tractor hydraulics.
Gerald J.
Sorry, Gerald, but hours just ain't gonna happen, especially now, as old as these tractors are...internal leakage will make it use up the reservoir in a while. 5, maybe 10 min. is a pretty good system in the real world.
The reservoir & cooler hold maybe 2 gal., & it's at 100 PSI max, that's what the cooler relief pops at. Actually it's free flow back to sump from the cooler if the main pump doesn't use it...
Other than that, good description! |
John Deere 4020 hydraulic problem
