|
| The 4010 and early 4020 tended to loose hydraulics from a worn out check valve on the charge pump in the transmission. I have a web page about that. http://www.geraldj.networkiowa.com/4020si.htm
Without that leak, most times the hydraulic reservoir (cooler) up front can supply oil with a double acting cylinder because the return oil on the SCVs goes to the front pump, not the sump. You get into oil problems WITH the rear pump running if you return oil to the transmission sump because the rear pump is only a few gpm while the front pump on a 40' is 22 gpm. Less on a 30'
All indications in service bulletin indices that I have (my collection is missing those bulletins) are that the side console 4020 doesn't have that check valve to wear out so it need not be replaced by putting on in the elbow that works in the early 4020 (last I fired up my fixed 4020, I pushed in the clutch, started it and lifted the loader after it had sat 6 or 8 months, so it still had hydraulic oil up front to run the loader), but the bulletins all point to your high pressure leak like the three point valve, an SCV, brake valve, the steering valve, or a split pipe in the transmission case and out of sight.
Gerald J. | |
|
A Look Back < < < John Deere 4010 Production
