Oil & Fuel What oil to use?

[Steve C]

I have a farm pro 2425 with about 100 hours on it. I bought it used with around 80 hours on it. I notice now that the weather is very cold it takes forever for the 3 point lift to work, also the power steering pump makes a funny screaching sound, almost like it is cavatating when cold. I also noticed that my rear blade won't stay in the up position, it slowly drifts down. I never had that problem in warmer weather even when lifting my 5 foot tiller, it would just stay where it was supposed to. Any idea what is going on there?:confused2:

I looked in my owners manual and it seems to list #20 diesel engine oil for the lift mechanism, it isn't real clear on what to use. Wouldn't standard hydraulic oil or even automatic transmission fluid work better than engine oil for this application? What are you guys using?

 

[Bob Rooks]

I have a farm pro 2425 with about 100 hours on it. I bought it used with around 80 hours on it. I notice now that the weather is very cold it takes forever for the 3 point lift to work, also the power steering pump makes a funny screaching sound, almost like it is cavatating when cold. I also noticed that my rear blade won't stay in the up position, it slowly drifts down. I never had that problem in warmer weather even when lifting my 5 foot tiller, it would just stay where it was supposed to. Any idea what is going on there?:confused2:

I looked in my owners manual and it seems to list #20 diesel engine oil for the lift mechanism, it isn't real clear on what to use. Wouldn't standard hydraulic oil or even automatic transmission fluid work better than engine oil for this application? What are you guys using?

It sounds to me like it was a crate tractor that wasn't properly prepped.
Others can elaborate on that.
Some manufacturers , without justification or supporting data, will say to use various formulations of motor oil as hydraulic oil, and there are many types of oil that may be used as substitutes, some only on a short term basis. Automatic transmission fluid (ATF), because of the friction modifiers blended into the base stock, is not recommended at all. Your average ambient temperature will dictate what grade of hydraulic oil to use, but most importantly it should be labeled as HYDRAULIC OIL ISO AW "grade #".
I have had very good results using a multi-vis hydraulic oil: ISO AW 32/46/68. It is good for a very wide temperature range.

 

[greg_g]

You are correct. AW32 hydraulic fluid works a helluva lot better. Or ISO32. Same stuff, just depends how it's labeled in your area stores. There were a few tractors like yours with 2 pumps, but not very many. Most have a single pump that runs all the hydraulics, including the steering. Assuming 1 pump, that squeal might be from a partially frozen priority valve. Let us know if changing to (clean) thinner fluid doesn't quiet that down too. I'd recommend flushing the system before putting good clean AW32 down on top of cruddy old Chinese #20 though. Besides being dirty, I wouldn't be surprised if there's water in it too.

But I don't think AW32 will help the leakdown on the rear lift. That's usually because the cylinder O-ring has become damaged. Usual cause is running the lift up too high (there are stops on the lift lever). Repair kits are inexpensive (O-ring and a plastic wiper or two) and pretty straightforward to install. Just a little messy is all. I'd drain the old crap out, install the kit, then refill with AW32.

//greg//

 

[Steve C]

Thanks for the information. My tractor was purchased from Homier by the origional owner. I don't know how it was prepped. I went to the farm supply store last night and bought a 2 1/2 gallon jug of "All weather" hydraulic oil. I then pulled the dipstick and the drain plug. It was a little low on oil and the stuff that drained out looked like 120 weight gear oil. About 5 minutes elapsed from the time the drain plug was removed till the "oil" hit the catch pan. That stuff was thick and moved slow. I have a theory about the bleed down. I think the oil is so thick that the pump cavitates amd fills the oil with air bubbles. Air being compressible makes the lifting action soft and as the bubbles combine to form larger bubbles they are more easily compressed and the lift slowly falls. I had no trouble with it in warm weather, but my pump didn't screech in warm weather either so it wasn't making air bubbles in the oil when it was warm outside. In warm weather I could raise the tiller and leave it in the up position and it wouldn't move. Weeks later it would still be "up".

I will let you know what it does when I get the oil flushed and changed. My plan is to drain all I can out of the lift housing, fill with new fluid then run the tractor for a while to mix the new oil with the oil that is left over that I couldn't drain, then drain it again when it is warm and fill with new hydraulic fluid again. As thick as the origional oil is, it will would take a month to drain even if I disconnected all the fittings and hoses. We have near zero degree temps at the moment and the old fluid is almost a solid. I will let you know if this works or not.
Thanks again for the information.

 

[greg_g]

Kerosene flush is faster and cheaper. Start the tractor and exercise the hydraulics. Hard. The more times the fluid goes through the pump, the warmer it gets. Warmer = thinner, thinner drains better. Leave loader and rear hitch in the air, shut off engine, drop loader and hitch. Drain. When you get as much out as you can, replace the drain plug and top up with kerosene. Start engine and repeat, remembering the loader and lift (that purges the cylinders and lines). Drain, but strain through a screen or cheesecloth. That way you can use the kero for more flushing. Repeat as required. Refill with AW32. That's AW32. Not 46 or 64 or 100. The bigger the number, the thicker the fluid.

//greg//

 

[Steve C]

You are correct. AW32 hydraulic fluid works a helluva lot better. Or ISO32. Same stuff, just depends how it's labeled in your area stores. There were a few tractors like yours with 2 pumps, but not very many. Most have a single pump that runs all the hydraulics, including the steering. Assuming 1 pump, that squeal might be from a partially frozen priority valve. Let us know if changing to (clean) thinner fluid doesn't quiet that down too. I'd recommend flushing the system before putting good clean AW32 down on top of cruddy old Chinese #20 though. Besides being dirty, I wouldn't be surprised if there's water in it too.

But I don't think AW32 will help the leakdown on the rear lift. That's usually because the cylinder O-ring has become damaged. Usual cause is running the lift up too high (there are stops on the lift lever). Repair kits are inexpensive (O-ring and a plastic wiper or two) and pretty straightforward to install. Just a little messy is all. I'd drain the old crap out, install the kit, then refill with AW32.

//greg//

I think you are right. I replaced the oil with all season hydraulic oil and the lift responded right away, as soon as the tractor started I had lift and no more screeching cavatating noises from the pump. Even in the summer time I had to wait a few minutes for the thick oil to give me lift. It still bleeds down though so I will need to pull it apart and replace the O rings. I will have to take a look at the stop adjustments. I think they are within specs but I am not sure. I have the manual that came with the tractor but it is not the best written manual I have ever seen.

 

[greg_g]

I forgot to mention that you might have a suction screen in the sump that could be collapsed as well. When fluid gets cold/thick/wet, it has a hard time getting through the screen.

Water weakens it, then suction from the pump slowly collapses the corrugation. Going by your description, I'd strongly recommend replacing it. About $25-$30 I think. Once you keep good clean and dry AW32 in there, you should never need another one.

Check your hydraulic fluid after a few days of use. It should be so clear that it's difficult to see on the dipstick. If it's already discolored, you NEED that flush I recommended earlier. If it turns out a flush is required, don't waste money on the new suction screen till that's done.

//greg//

 

[Steve C]

should I take the selector valve apart first to see if the problem is with the valve or is that pretty unlikely? I don't know much about how these things work. Would a bad O ring in the valve cause it to bleed down?

I always try to do the easy stuff first but not if it just a waste of time.