What do you guys use for hydraulic oil? I purchased the operators manual and it is not real clear to me what I should be using for operating with the majority of the time ambiant temperatures being 32f thru 95f. It's a little conflicting. While I'm at it ... what about engine oil?
You have not defined which 312 model. I would expect there would be differences with each model. This is what the operators manual says for a 312B - pretty straight forward. If you don't like Cat HYDO with a little research you can find a good 'equivalent' oil. It is not uncommon and you -can- substitute engine oil for hydraulic in some cases/equipment. However there are differences in dispersants which may cause emulsification of water in high humidity use.
I guess my confusion is the last sentence (ISO 46) would normally be selected. 312 is the model 1994.
Forget the last bit and re-write the first sentence as “Any premium ISO46-viscosity industrial hydraulic oil that has passed......” Does it make more sense now..?
Oh ok... So any premium aw32 (10 wt) with those specs should be safe. I wonder if there are any advantages of using the thicker viscosity aw46 in older machines. Thanks
With all oil just make sure it has passed the tests and is certified to the required standards. Avoid anything that says something like " also recommended for use in..."
For your ambient temperature range an SAE10W or ISO AW32 would be fine in the hydraulic system. 46 might be a tad heavy. Engine oil either SAE 10W/30 or 15W/40, API CF-4 or better specification-wise.
Thanks so much... I'm doing a complete service including all fluids.
A lot of people think they have to use Cat fluids - not true. However I would always recommend to use a good fluid from a major oil company such as Shell, Texaco, Conoco, Mobil, Chevron, etc. Stay well away from bargain buckets (usually yellow) in the local parts supply house.
If I was doing the service I would have the -hydraulic oil- ANALYZED to see if a change was needed before spending a lot of money on 45 - 50 + gallons of oil. Change the filters but if the hydraulic oil analysis is good. . . . .
AW46 is the usual hydraulic oil used in the Pacific Northwest. Caterpillar has been out of the oil business for some years now. I've yet to see any wear difference in high hour components when using a quality hydraulic or engine oil and doing maintenance to manufacturer's specifications.
I use a TO4 spec 10W all year round (-10°F to 95°F) fleet wide. 30W makes them too sluggish at temps under 40°F.
That's news went to local Cat store today and they had couple barrels and maybe a 100 buckets of Cat branded oil. Guess it must be old stock. Bob
It's rebranded stock. Someone else's oil in Cat buckets and barrels.
It always has been. Bob