Changing hydraulic fluid to ATF

[dlundblad]

My splitter that normally starts on the 1st or 2nd pull didn’t start yesterday in single degree (F) temps. It was somewhat difficult to pull too so I’m assuming it’s the hydraulic fluid. Currently has AW46 in it. The totally capacity is 6.5 gallons, but the manual recommends filling it to no more than 5.

The manual suggests ATF in temps below freezing. I’m also assuming ATF would be okay in warmer temps as well. It’s my understanding that hydraulic fluid and ATF foam when mixed. Perhaps fill with a cheaper ATF, run it a bit, and then do another refill with say Maxlife? I plan on doing a filter change as well.

I figured Maxlife would be a good choice. Synthetic and relatively cheap per gallon. Plus, I always some on hand. I was entertaining full syn Kubota UDT2, but it looks like the Max is a tad thinner at colder temps.

 

[Mainia]

I like your flush idea and fluid choice.

 

[Pelican]

My splitter that normally starts on the 1st or 2nd pull didn’t start yesterday in single degree (F) temps. It was somewhat difficult to pull too so I’m assuming it’s the hydraulic fluid. Currently has AW46 in it. The totally capacity is 6.5 gallons, but the manual recommends filling it to no more than 5.

The manual suggests ATF in temps below freezing. I’m also assuming ATF would be okay in warmer temps as well. It’s my understanding that hydraulic fluid and ATF foam when mixed. Perhaps fill with a cheaper ATF, run it a bit, and then do another refill with say Maxlife? I plan on doing a filter change as well.

I figured Maxlife would be a good choice. Synthetic and relatively cheap per gallon. Plus, I always some on hand. I was entertaining full syn Kubota UDT2, but it looks like the Max is a tad thinner at colder temps.

Would not run ATF much above freezing as atf & hydraulic fluids expand at a different rate and you may exceed the Max Capacity.

 

[dlundblad]

Would not run ATF much above freezing as atf & hydraulic fluids expand at a different rate and you may exceed the Max Capacity.

I could run it a gallon or so low if needed. The add and full range is pretty wide. My main concern is it being too thin in warmer weather.

Also, it has a breather and would just ooz out.

 

[tom slick]

Here’s an old but interesting post
Log splitter atf

 

[Spectre694]

We have a few genie work platforms at work that spec chevron rando/rykon MV (iso 32 multi viscosity) we use Dex/Merc in them without any issues it is very close spec wise.

 

[bruce381]

use aft as a 46 oil is fine no need to worry about it AFT will flow at -30 or 40 so woulc be better for cold.
Do no think a mix would foam any more then normal.

 

[MolaKule]

You could fill it with 5+ gallons of MaxLife and run it during the winter. By the time summer gets here, you'll need to change it anyway to get rid of the moisture that has condensed in the system.

 

[dlundblad]

You could fill it with 5+ gallons of MaxLife and run it during the winter. By the time summer gets here, you'll need to change it anyway to get rid of the moisture that has condensed in the system.

How would it get moisture in the system?

 

[MolaKule]

How would it get moisture in the system?

Water Contamination in Hydraulic and Lube Systems

Water and oil don't mix - it's a well-known adage in the lubrication business. But what exactly does that mean? Yes, water contamination can be problematic, but how can water be measured? Can it be...

www.machinerylubrication.com

 

[dlundblad]

Water Contamination in Hydraulic and Lube Systems

Water and oil don't mix - it's a well-known adage in the lubrication business. But what exactly does that mean? Yes, water contamination can be problematic, but how can water be measured? Can it be...

www.machinerylubrication.com

So even a system that never sees rain can collect water?

 

[MolaKule]

So even a system that never sees rain can collect water?

It can collect moisture due to heating and cooling cycles. When cooling down, fluid volume decreases which decreases internal pressure below atmospheric pressure, i.e.,, this is when it "sucks in air." Air has a certain moisture content. Moisture condenses in the fluid as water.

 

[Langanobob]

My splitter that normally starts on the 1st or 2nd pull didn’t start yesterday in single degree (F) temps. It was somewhat difficult to pull too so I’m assuming it’s the hydraulic fluid. Currently has AW46 in it. The totally capacity is 6.5 gallons, but the manual recommends filling it to no more than 5.

The simple solution would be to keep it in a heated garage but obviously that isn’t practical. I think I’d try changing the engine oil to a synthetic with good low temp characteristics first. It will be cheaper than changing out all that hydraulic fluid and might just solve the starting problem. Fresh fuel too and a new spark plug.

Or, you could split your wood in the fall but then it seems we never have enough to last through cold winters, especially like this year when we’re home more than usual. I’m running low too.

About water condensation and changing in the spring, with all due respect to MoleKule that may be true in academia but in the practical world I don’t think that’s necessary. You might get some condensation but hydraulic systems run hot enough to evaporate it pretty fast. I have half a dozen machines with hydraulic systems, never had a problem and if I arbitrarily changed the fluid every year it would seriously cut into my beer money. If your hydraulic fluid gets enough moisture in it that it looks milky, yes, change it!

 

[MolaKule]

About water condensation and changing in the spring, with all due respect to MoleKule that may be true in academia but in the practical world I don’t think that’s necessary. You might get some condensation but hydraulic systems run hot enough to evaporate it pretty fast. I have half a dozen machines with hydraulic systems, never had a problem and if I arbitrarily changed the fluid every year it would seriously cut into my beer money. If your hydraulic fluid gets enough moisture in it that it looks milky, yes, change it!

As per the discussion here:

ATF Fluid instead of Hydraulic Fluid

Hey Guys - And Bob! Got a question. I build 5hp racing engines for kart racing. We use a hydraulic dyno for testing the engines. When I built my dyno I talked to the guys at Haldex Barnes and they recommended I use ISO-68 AW20 for the fluid. So far it has worked great for me. Now, talking to...

bobistheoilguy.com

this wood splitter here was not an academic exercise but actual experience (with the cause as mentioned in post #12) when the splitter was left outside but covered when not being used. The breather was the main point of moisture ingress.
,
Only if the fluid temperature can rise above 100C for long periods can the moisture be liberated. In our case, the fluid temps never rose above 100C, because of I-beam tank's heat sinking (heat rejection) capability.

I also discovered that the filter I used could also trap a certain amount of moisture as well as contaminants, so filter changes from one season to the next is also important.

 

[dlundblad]

It can collect moisture due to heating and cooling cycles. When cooling down, fluid volume decreases which decreases internal pressure below atmospheric pressure, i.e.,, this is when it "sucks in air." Air has a certain moisture content. Moisture condenses in the fluid as water.

What I don’t get is there’s many hydraulic systems that should be changed based on hours used and not yearly. Tractors, heavy machinery etc. all of which have breathers just like my splitter.

 

[dlundblad]

The simple solution would be to keep it in a heated garage but obviously that isn’t practical. I think I’d try changing the engine oil to a synthetic with good low temp characteristics first. It will be cheaper than changing out all that hydraulic fluid and might just solve the starting problem. Fresh fuel too and a new spark plug.

Or, you could split your wood in the fall but then it seems we never have enough to last through cold winters, especially like this year when we’re home more than usual. I’m running low too.

About water condensation and changing in the spring, with all due respect to MoleKule that may be true in academia but in the practical world I don’t think that’s necessary. You might get some condensation but hydraulic systems run hot enough to evaporate it pretty fast. I have half a dozen machines with hydraulic systems, never had a problem and if I arbitrarily changed the fluid every year it would seriously cut into my beer money. If your hydraulic fluid gets enough moisture in it that it looks milky, yes, change it!

The splitter is just over a year old. I’d guess around 10-15 hrs. Spark plug should be fine. Has a Honda engine which typically starts on the first or second pull. It’s currently filled with M1 0w40. I guess I could go 0w30 or 5w20, but I don’t think that’s the issue. I always use E0 fuel.

Storing in a heated garage is possible, but not practical.

I did cut my wood in late summer and fall. Had about 4 cords and am nearly out now. Wood is my secondary heat so if I run out, I won’t freeze.. it’s just nice to have.

I agree with the added maintenance cost of yearly hydraulic systems. I’d be going through about 20 gallons a year and at $22-ish per gallon, that’s a lot of beer money indeed.

 

[DriveHard]

Why not just drain and fill with ISO32 hydraulic oil?
ATF can sometimes have additives that don't play well with materials in hydraulic systems - we don't test for that.
Log splitter systems when run for a bit will get more than hot enough to boil off any water they accumulate.

 

[Motu]

I 2nd or 3rd the ISO32, and use it all year.

 

[dlundblad]

Why not just drain and fill with ISO32 hydraulic oil?
ATF can sometimes have additives that don't play well with materials in hydraulic systems - we don't test for that.
Log splitter systems when run for a bit will get more than hot enough to boil off any water they accumulate.

The manua only allows for the AW46 and specifies the DexIII for cold weather operation.

 

[MolaKule]

The only time I have seen leaks when using any hydraulic fluid (ATF is simply a highly additized hydraulic fluid) is when a seal was previously very worn or damaged by foreign material.