Older, Sears Splitter Hydraulic Oil Questions

[TruePatriot]

Hey, all,

I have the tiniest gas-powered wood splitter I’ve ever seen.

It is a 5 h.p. Sears (engine code date 1981, appears to be original engine). The I-beam is LESS THAN 3” x 2.5”! The overall length, counting the tires, is about 5.5’. The stroke is only 19 and ¼”.

Yet I’ve split rounds up to 24” and it doesn’t get stuck all too often. I just whittle away at the edges on the big ones. It definitely beats hand splitting!

It was given to me not too long ago, and had no spark—I cleaned the carb, changed the tank, got it running, used it awhile, then spark went away, and it sat outside. Now I’ve gotten it going again (corroded condenser wire) and I’d like to change the hydraulic oil.

Question 1: What Type of Hydraulic Fluid Do I Use?

What is in the tank (which is no bigger than a lunch box) appears to be ATF—Type “U” for “unknown.” LOL.

I already have some hyd. oil for my trencher I’d like to use. It is:

Napa Anti-Wear Hydraulic Fluid
AW-32
85-905

I’m assuming the “85-905” is a Napa part number, because it sure isn’t as thick as 80-90W gear oil; nor is the oil in the splitter particularly thick—as I say, it appears to be ATF, in that it’s pinkish—I fear it may have water in it, however, so I would like to change it.

The Napa stuff I have is clear and/or yellowish in color.

Question 2: How Do I Drain the Hydraulic Fluid?

a) The hoses to and from the tank are crimped on; I’m not sure I can cut the crimp off w/o damaging the hose, but if I were successful, will I be able to keep the hose on with a std. hose clamp? I’m assuming the hose leading TO the pump, at least, is under low pressure?

b) Is there someplace else to drain it from? The only “fittings” on the thing are up high, on the valve body and ram, and thus, would not drain much, if at all.

c) I’m assuming the ram should be all the way retracted, for draining? Or is there the same amount of fluid in a double-acting cylinder, regardless of position?

d) I’m assuming I will only be able to change the fluid in the tank, and that what’s in the cylinder and valve body will stay in there, to be mixed with the new fluid and (partially) changed next time?

Question 3: If There’s Water in Fluid, Will It Damage the Pump?

I’m assuming there’s water in the fluid, what with hydraulic fluid being hygroscopic, and this splitter being outside, probably for years--plus it looks a little "milky". If I run it as is, and there IS water in it, will I damage the pump?

I will try to post pics later, but I do not know how to resize them.

Thanks again,

 

[brad068]

TP,

The hyd oil is usually an all season oil anywhere from 20 to 30W. That is probably what the napa oil is that you have. You can use atf but if the pump has alot of use atf is so thin that it can bypass in a worn pump.

Hose going to pump is not under pressure its under vacuum. Your better off breaking the return hose and placing it in a bucket. Use a shop vac and stick the hose in the tank fill hole. This will aid in not making such a mess while cutting the hose. Plug the tank side and keep the new oil close and keep adding oil to the tank while the engine is running slow until the oil cleans up. You can remove the cylinder hoses (if any) and slide the ram by hand purging the fluid out of the cyl. This can get messy but it can be done.

 

[kevin j]

AW32 is the viscosity. AW = antiwear hydraulic additives 32 is ISO viscosity range. (centistokes at 40 degrees C, not that it matters) 32, 46, and 68 are most common for hydr oil.

32 is about like ATF, I don't have my charts here to relate to SAE motor oil grades. 46 is more commonly used in all season hydr equipment. 68 is more for heavy hydrostatics for summer use only, not good for winter startup.

If any visible clouding, dump the oil. That is lots of water. It won't do immediate damage, but could plug filters, is poor lubrication, causes rust, and other long term issues.

If you can't disconnect a hose, I would put the shop vac on the inlet to tank to pull a vacuum. Cut off the return hose (from the cylinder/valve), then turn off the shop vac and drain the tank. Cycle the cylinder a couple times to push oil out.

Then since the tank is so small, I'd fill it with the 32 you have, run the return to a bucket, and start the engine, or pull it over with the rope or the starter. Hold the cylinder valve one way so you cycle the oil out of the cyliner, then retrqct and do the same. Basically send the oil one way from tank to system to bucket. until the tank is low.

Then add a return filter, a longer return hose, hook it up and refill with new oil. I'd use 46 grade, not 32, just better for system. If you aren't expecting using it below say 30F, I'd use 68. ATF or motor oil are ok, but AW hydr oil is better if you can get it. Motor oil in particular emulsifies water.

With only a gallon, after the first change, I'd then run it and cycle under no load maybe 25 times, then dump it again. This time you will have new hose connection and hopefully easier. Change filter again and refill with new oil. And change the tank breather/filter.

With such a small system, that is far easier, cheaper, and gets the water out. When a system holds several hundred gallons, way different ways of dealing with water and oil issues.

kcj

 

[boostnut]

Looks like you've been given some good advise on which oils to use and how to change them. I would suggest considering a minor modification to your splitter. A little tiny hydraulic system has 1 major problem, heat. I had a small system on my Didier splitter (which is probably who manufactured yours) and switched to a larger tank. If you have the capability to make this change do yourself a favor and upgrade. Good luck!

 

[TruePatriot]

Garnification and kevin j,

Sorry I didn't get back to you sooner, but thank you for the great responses!

I've printed them, and will get as much of the old fluid out as I can, and run what I have through it, to be changed out again. I will also look into adding a filter (and mount) since it never had one (!?).

Whoops--boostnut--didn't see your response. Well, that makes sense, and I could mount a taller tank on this, if I could find one. Speaking of tanks--this one is only half full--does that sound right? Because that means I have even less fluid to dissipate the heat--I'm thinking it should be at least 3/4 full, which still leaves some room for expansion? But thanks--I will start thinking about a bigger tank, as well.

Thanks again--this place is the best!

Peter

 

[bill*67]

just a quick thought, if your going to add a larger tank , make sure you put a drain valve in it , or on your old tank if you use it.

 

[TruePatriot]

wildbill,

Thank you for this:

just a quick thought, if your going to add a larger tank , make sure you put a drain valve in it , or on your old tank if you use it.

That would have made what I have to now easier, had they included a drain valve--thanks!

TP