Rando/Rycon 46 Compatibility

[Old Scout]

Appears Rando/Rycon 46 only comes in 5 gal containers. Anyone know if ATF or other hydraulic fluids are compatible with "46" so you can top-off with a quart or two between major fluid/filter changes?

[EngineerMike]

petro based oils are generally highly miscible, shouldn't be a big deal.

[Old Scout]

EM--Thanks--so what do you think....if needed, go back to a quart of 15W40 [valvoline], or use ATF, or does it matter? Curious do you suppose Rycon 46 is 6 units[?] thicker at ops temp than 15w40? Not sure what a viscosity unit is called....

[EngineerMike]

I'm not sure of how the viscosity ratings work exactly. The premium Rando HDZ in my rig is supposed to have better quality retention across a wide temp gradient (iirc we determined Rykon was rebranded to Rando for whatever the heck Madison Avenue magic that engendered). I'm guessing you will never know the difference regardless. If there is any change in my braking after going to the dramatically more expensive hydraulic fluid, you might find it with a micrometer if you knew how to read the micrometer. As to my foot, its not that smart. IIWMI'd use the low test stuff and not sweat it.

Here is an interesting aside about hydraulic system that just came my way off line. Alpiner emailed w/overheating problem, not severe but would have been in dead of summer; found he was marginally low on coolant and topped off. Fan didn't turn at all at idle, turned some if he ran temp up to 200+ then stopped & immediately checked fan (very slow turns). But at speed and after topping off coolant, he didn't overheat so assumption was fan was turning at high engine rpms. Theories regarding fan motor maybe bad, wax valve maybe bad... as there should be ~800 rpm on fan blades at idle per my conversations w/WRV in mid 2005.
Mechanic checked out rig, found owner had never changed hydraulic oil or filters. Original filters were disintegrating. My guess is debris from filters was clogging fan motor at low rpms & low hydraulic oil flow. Mechanic changed oil & filters, all is well, no new parts needed so far.