Curious if anyone is running this product? We have a unique opportunity to get the 424 cheap. Our Excavator that is in desperate need of fluid change, calls for a 10w oil. The 424 I think comes from a 30w base and comparing the specs of CAT HYDRO oil, the 424 is certainly higher viscosity. This will be going in an old machine. I have heard that older pumps might do better with higher viscosity due to reduced bypassing of worn components but I can also see where a higher viscosity would run hotter too. I think anything would be an improvement over what is in the machine but curious if anyone is running it as a hydro fluid with great success? I know a very large construction co uses it exclusively on their lube truck for every machine as a trans and hydro fluid.
Mobilfluid 424 is a multi-purpose tractor fluid (MTF) that meets API GL-5 specification and can be used as a replacement in certain cases for 80W EP oil. It also meets Caterpillar TO-2 (but not TO-4) so it's a bit of a "bitza" as regards a fluid. Not specifically a hydraulic oil, and not really a power train oil either. Designed for machines meeting older (or less onerous) specifications I would guess. Everything in the specification indicates it can be used as a hydraulic oil. Viscosity of 9.3 puts it somewhere between a 10W (6.5) and a SAE 30 (11.2). So call it an SAE 20 viscosity-wise. So long as you aren't in really cold ambient temperatures it should work. Even if you are in low ambients the machine will probably just need a careful bit of warming up on cold days.
I know the guys using it now run this product in brand new machines from NH skid steers, to CAT loader and excavators. Because the lubber cannot carry every specified oil on the truck, they had to find something that fits everything I guess. I know the company in question does not skimp on fluids so I am assuming they found it to be a great fit for all equipment. I did not realize you did not pay much attention to the 40C viscosity data. Cold starts are what worry me the most I guess even though this machine will never run below 15F unless there is some sort of emergency and in most cases, that number would be 30F or so. I am really surprised no one thought to install a hydro system heater for really cold conditions. I would think the tank would be a great place to add some heat before cold starts.
If it's cold outside you should really be running a lower viscosity oil .......