What are typical working pressure and pump flow figures in tractor hydraulics?
In tractor hydraulic systems the working pressure is typically in the 180–220 bar range. On tractors in the 60–100 HP class the pump flow is typically on the order of 60–90 L/min. These values vary with the model and the pump type; for an exact figure, check the hydraulic table in the tractor's operator manual.
The two quantities determine different things:
- Pressure (bar) determines how much force you can produce. The typical range is 180–220 bar and the upper limit is set by the relief valve setting.
- Flow (L/min) determines how fast you move. In the 60–100 HP class you typically see 60–90 L/min. As flow increases the same cylinder fills in less time, so the hitch lifts faster.
Lifting force is roughly pressure multiplied by the cylinder cross-sectional area; the linkage geometry and pivot points convert that force into the lift capacity at the hitch end.
Electronic retrofit kits change none of these values. LFT20 and LFT54 do not enter the hydraulic circuit; they move the tractor's existing control lever via the cable. So fitting a kit does not increase or decrease your lift capacity, it only changes the way you operate the lever. If your hydraulic performance is inadequate, the fix is not in the kit but in the pump, the filter, the oil level and the relief valve setting.
Full topic: Converting a tractor hydraulic lever to electronic control