If "Boss" says to put ATF in it, then I'd be inclined to stay with that. As far as leaks are concerned, if the system isn't leaking now the only reason it would start leaking after a fluid change would be if any plugs/fittings etc weren't tightened fully after draining the old fluid. Is the unit working OK now or is it giving problems of any kind, and how long has it been since it had a fluid change?
By "plow fluid" what is it that you mean exactly? Regular hydraulic fluid, or one of the "special" fluids such as what Meyer makes for theirs?
Karl it's recomend that you change the fluid each season, which consists of draining and flushing the tank;cylinders;hoses and valve body. By all means change over to a low temp hydraulic fluid, Boss now uses a low temp hydraulic fluid which has deicers and rust inhibitors for more power unit protection. In most cases you will find that the unit will operate faster and smoother along with less current draw
I got my new Fisher V-plow this year and assumed that it had the Fisher oil in it... So I went up to buy some to have on hand and they told me that they put ATF in the V-plows... I looked and sure enough it has the ATF in it. I would think that any plow with the pump on the outside would use the hydraulic oil not the ATF... Do you all think I should switch over to Hydraulic oil for next year?
I would change it. Even if the dealer says it will be fine I would still switch it over, just because they sell the plows does'nt mean they are'nt subject to going by the "old ways". Cheap insurance IMHO.
Go with the low temp special plow fluid. It's worth it. I spent $1200 tracking down a problem last year with a high amp drain on the plow motor (that's another huge, painful story in itself). One of the major problems was that I was using ATF fluid (Western Plow). I changed to the premium plow stuff - best $20 I've spent this year!!! Do your self a favor - spend the extra couple of bucks.
Fisher; Boss; Meyer ; or Western fluid with work just fine in your plow. What you want is a "low temp" hydraulic fluid, there is a few other brands that are sold through the aftermarket which will give you the same results. We fill every one of the new plows that we sell with Kendall Glacier Blue"low temp" hydraulic fluid. And "highly" recomend the change over on all the units that come in for service.