Fluid for backhoe with PTO pump?

[Ken P]

Folks -

I have a Woods 6500 hoe on my Kubota 2410, it works off a PTO pump. I got it used about a year ago, and I do not know what kind of fluid is in there now.

I need to top off the fluid, and have some SUDT2 on hand. The manual calls for "SAE Hydraulic Transmission Fluid" or "Type "A" or "F" ATF", but sternly warns against mixing oil grades or types. Will the SUDT2 do for now? And, when I fully change the fluid, which of the recommended fluids should I choose, and if I could get a specific brand name to look for, I'd appreciate it.

Thanks - Ken

 

[TedLaRue]

If you don't know what fluid is in it now, and the manual "sternly warns against mixing oil grades or types", nobody here is going to tell you what fluid to add.

Bite the bullet and do a full fluid change. Choose the fluid from the list of "approved" fluids which are readily available, with some consideration of the cost. The "SAE Hydraulic Transmission Fluid" would be your choice only if your tractor's transmission and your hoe share the same fluid.

 

[Farmerford]

If it were me I would use the SUDT2. First, Kubota says it is compatible with all hydraulic/transmisson fluids. Second, most pto pumps are tolerant of a wide range of fluid viscosities. The most critical factor is viscosity at the highest operating temperature of the system, when the fluid is at its thinnest and provides the least protection against metal to metal contact.

Although pump manufacturers have different specifications for minimum viscosity, I think 10 centistokes (cSt) kinematic viscosity is high enough for most. I recall that the KV of SUDT2 at 100deg C is between 9 and 10 cSt. So the SUDT2 you add will have to reach almost the boiling point of water before it thins out enough to provide only marginal lubrication. I have a B2400 and I don't believe it's 18 pto hp can get a few gallons of fluid that hot in a month.

 

[brucew44guns]

How many gallons of fluid are you talking here? A pail?, maybe 3 or 4 gallons? Not familiar with your hoe, but I think I would consult the builder, identify the oil, and change it out now. Peace of mind and perhaps longer life on equipment will ensue.

 

[RickB]

How many gallons of fluid are you talking here? A pail?, maybe 3 or 4 gallons? Not familiar with your hoe, but I think I would consult the builder, identify the oil, and change it out now. Peace of mind and perhaps longer life on equipment will ensue.

Consult the builder? The OP quotes the operator's manual. He even stated the published recommendations in his first post. He can't go wrong by folllowing them. I can't imagine what advise could possible be better.

 

[Coyote machine]

You have the manual. Drain it and use the recommended fluid per the MANUFACTURER's specs. This way no guessing, no screw-ups.
Case closed. :thumbsup:
CM out.

 

[Ken P]

Thanks for the replies.

I am planning a full fluid change out, but I need to order a filter, so that will have to wait a few days. I was just wondering if a small amount of SUDT mixed with whatever is in there would be ok until then, so I can finish the current digging job.

Brucew44guns and TedLaRue- it'll be 5 1/2 gallons. And, no, this is not shared with the tractor transmission, it is a separate circuit just for the hoe (runs on a rear mounted PTO pump). So, for this, which brand/type fluid would you use (for the full change-out)? I realize there are many choices - which is what gets me confused. It's not entirely clear to me - even after trying to read online - what the difference is between hydraulic transmission fluid and "ATF" which I assume stands for automatic transmission fluid. Is this the same stuff as I would put in my car?

I appreciate the advice. It's helpful to a newbie to have a specific vendor or brand or something to help select amongst the myriad fluid choices, as it's not always clear to me which of the fluids on the shelf match the recommendations in the manual.

Ken

 

[LBrown59]

Wouldn't using a different fluid in the BH cross mix with the Hydro in the tractor tranny?

 

[RickB]

Wouldn't using a different fluid in the BH cross mix with the Hydro in the tractor tranny?

The OP mentioned in his initial post AND a second time that this machine has a separate system powered by a PTO hydraulic pump. :confused2::confused2: Pretty obvious that the BH fluid isn't likely to mix with that in the tractor.:mur::mur:

 

[Coyote machine]

How can you be down 5 1/2 gallons and still using the hoe?! :confused2:
How many gallon capacity is the entire tank?
If you're down that much and you've been using the hoe I'd say you're likely to do little damage adding whatever you choose...hyd trans fluid, ATF, etc. or possibly cod liver oil or used fry-o-lator oil, or maybe Johnson's Baby Oil. If you value your machine so little as to just guess, then it really doesn't matter anyway. If it were me, I'd wait and get the new filter, change it and the complete oil for the hoe, and THEN finish the digging job.:thumbsup: