I checked the manual for my M135GX loader and it does not state any limitation. It says to press the master button which will put the third function valve into the loader oil circuit (and an additional circuit that will generate heat). Then it states to press the upper rocker direction to flow oil out the a port and into the b port, or lower rocker button for oil out b and into a. It states oil will continue to flow as long as the button is depressed. It does not give a warning that anything will overheat if the circuit runs continuous flow. However, why do they add the master solenoid valves to control oil flow to the third function valve if there isn't a need? It would simplify the circuit and reduce cost if this electro/hydraulic section was not used. My L6060 did not come with a loader manual but it has the same control buttons as my M135GX. In heavy use my M135GX hydraulics run hotter than I would have permitted on the products for which I had design responsibility. I was concerned enough about hydraulic oil temperature to have an alert light and horn. I have measured temperatures well above the limit I used on my tractor - measured at the hydraulic oil filter and hydraulic pump. I would proceed with caution. The hydraulic oil cooler on my 4 Kubotas seem very small compared to those I used on my product. In one way that is fitting because my machines were 100% hydrostatic drives while my M135GX is primarily gear driven with hydraulic clutch pressure engagement, but my L6060, RTV900XT and GR2120 are all full hydro.
