Making an old skid steer last?

Status
Not open for further replies.
Joined
Dec 3, 2016
Messages
15
Location
usa
I recently bought an old New Holland Skid steer, L325. The Hydro tank is marked "use only 10W40 SE oil".

Fair enough, I know some use motor oil as hydro fluid.

My question is, for it's upcoming oil tank drain and change, Can I do better? I'd like to boost the charge pressure up a bit, spec says it should run between 90-150 psi. It starts up cold at 120psi and as it gets hot, it drops to about 110/105 and runs there all day long. No leaks, everything works as strong as an ox.

I've never messed with any hydro system this big and complex before and, as it would cost 10x more than I paid for it to replace (if they can even be found) the pumps I'd like to try to keep it as healthy as possible as long as possible. I know after 40 yrs or so, the innards are a bit worn.... it still lifts and carries a full dump of limestone with no problems.

Would replacing the 10W40 SE (SAE now) with something like 10W50+ be stupid or pointless or a good idea? I've had people tell me cut the 10W40 with lucas oil stabilizer or hydro booster but I'm not real keen on that idea. Since oil tech is so much better now than it was in 1978, I'm curious to know how I can get as much life out of these pumps as possible starting with the next oil change.

Should I just stick with the standard 10W40SAE, boost it up to 10W50 or start using some magic mucus made for old hydros of some kind? Or is there some kind of standard hydro fluid that should replace the motor oil it was designed to used?

I'm still learning as I go here, so I'm trying to err on the side of caution.
 
Good thread... thanks!

I could ask the manufacture directly but I can't find Cessna/Eaton on the web to contact them as yet.
 
My woman said "it's ran for 40 yrs on the oil on the tank label, why change it?"

She might be on to something.
 
Originally Posted By: zeng
I would consider HDEO 15W40 CD/CE/CF for it's shear stability against PCMO 10W40.


So...like Rotella diesel engine oil?
 
Originally Posted By: zeng
You got it, NJ.


Rotella has several kinds... what type would be preferable?
 
My theory? Better additives might protect old worn parts and extend its usefulness for a while. I'd think its better to try that before it starts showing real signs of wear.

But I dunno... its why I asked.
 
I think you might need an oil with ZDDP in it.

My mini skid steer (circa 2005) came with a big sticker on the hydraulic oil tank that said: USE 15W-40 or 10W-30 DIESEL ENGINE OIL ONLY.

Well, in 2011, they (Toro) changed the spec when the HDEO oil formulation changed. Now the spec calls for Mobilfluid 424 or the equivalent.

So... I would be wary of using modern engine oil in that equipment. Apparently, hydraulic pumps like zink.

Here's what they sent out:

October 2011

Dear Toro Customer:

The purpose of this letter is to inform you of a change in Toro’s hydraulic oil
recommendation for your Sitework Systems product(s). This is necessary due to a
change in the formulation for the latest diesel motor oil API specification, CJ-4.
It has a reduced amount of ZDDP anti-wear additive and no longer meets the hydraulic system
requirements for Sitework Systems products.

Approved Hydraulic Fluids:

Toro Premium All-Season Hydraulic Fluid (Mobil DTE-15M Special), which is blended
for and available from The Toro Company through your dealer. This fluid is now
our factory original equipment hydraulic oil and contains a red dye to help in
locating oil leaks that may occur.

Premium Transmission/ Hydraulic Tractor Fluid (Mobil 424 Tractor Fluid), also
available from The Toro Company through your dealer, and other sources.

Previous specification diesel engine oil, API Specification CH-4 or CI-4
.
These fluids are compatible and can be mixed together. In the event
that none of these fluids is readily available please contact your local Sitework Systems dealer for possible
alternative “industry equivalent” fluid.

The information provided in the equipment Operator’s Manual no longer lists the correct
information on the type of hydraulic fluid to use. Included with this letter are two decals
with the new hydraulic fluid recommendation. Place one on the Operator’s Manual
cover and one on the unit by the hydraulic oil fill cover to remind you of this change.

Sincerely,
Toro Customer Care
 
Run a modern hydraulic fluid of the weight equivalent to the engine oil you are using now. I think that would be around a ISO 100. That should be more shear stable...although would effect your cold temp operation if you use it during the winter very much...were you may have to switch to a lighter grade in the winter months. I would never suggest motor oil in a hydraulic system.

Do not turn up the charge pump pressure unless you want reduced performance. Turning up charge pump pressure will burn more fuel, put higher heat load on the system, and do nothing to increase the life of the components. If anything, it can reduce the life of some parts of the system. If your system reliefs are referenced to case pressure...you can actually reduce your tractive effort by increasing charge pressure, requiring more system pressure to do the same work...further stressing components. If there is not a low loop problem, the charge pressure is just fine.

A charge pump in your hydraulic system is not like the oil pump in your car. It does not supply positive pressure to bearings or camshafts. Most lubrication in a hydraulic pump is passive, or pressurized and balanced by system pressure.
 
Last edited:
Quote:
Run a modern hydraulic fluid of the weight equivalent to the engine oil you are using now. I think that would be around a ISO 100

I don't see any ISO 100 but is this stuff suitable?

https://www.tractorsupply.com/tsc/produc...il?cm_vc=-10005

It says the SAE Viscosity is 10W30. If I can find what they call UNiversal Tractor Fluid of that ISO is that good?

Odd thing, the skid steers tank label says use only 10W40, the operators manual says use Dextron ATF. I don't know why they don't agree on that. What was in it when I got it looks and smells like motor oil not ATF. ATF s a lot thinner than motor oil so that one really confused me. Why suggest ATF in the book but label the tank to take 10W40?

Quote:
Do not turn up the charge pump pressure unless you want reduced performance.


There is no way to turn it up on this thing as far as I see. It just has the book specs of what is the normal range, so I stuck an oil gauge on it as the pressure sensor and buzzer doesn't work, (I put it on like the service manual says to for testing, on the pressure sensor line) the spec says its suppose to go off )the buzzer and the light) under 50PSI. The spec range of the charge pump says between 90-150 PSI so... I watch the gauge. I was under the impression that midway between 90-150 would be optimal but as long as it runs about 110-120 all the time, I guess I won't worry about it. I'm not too proud to admit I have really no idea what that charge pressure is or means. All I know is the book says "between 90-150". LOL

Quote:
If there is not a low loop problem, the charge pressure is just fine.


I wouldn't know if it did... what are the signs of a low loop problem? As far as I can tell it runs perfectly fine, no struggle digging or lifting or driving. Works like a bear for as old as it is. Let me know what that is and I'll watch for it.

Quote:
I think you might need an oil with ZDDP in it.


My thinking was this thing is old, oils are different than they were back in the 70s, so what it was getting with 70s era motor oil is probably not what its getting with 21st century motor oil. Thus my questions and confusion.
 
Last edited:
Originally Posted By: nyquil_junkie
Quote:
Run a modern hydraulic fluid of the weight equivalent to the engine oil you are using now. I think that would be around a ISO 100

I don't see any ISO 100 but is this stuff suitable?

https://www.tractorsupply.com/tsc/produc...il?cm_vc=-10005

It says the SAE Viscosity is 10W30. If I can find what they call UNiversal Tractor Fluid of that ISO is that good?

Odd thing, the skid steers tank label says use only 10W40, the operators manual says use Dextron ATF. I don't know why they don't agree on that. What was in it when I got it looks and smells like motor oil not ATF. ATF s a lot thinner than motor oil so that one really confused me. Why suggest ATF in the book but label the tank to take 10W40?

Quote:
Do not turn up the charge pump pressure unless you want reduced performance.


There is no way to turn it up on this thing as far as I see. It just has the book specs of what is the normal range, so I stuck an oil gauge on it as the pressure sensor and buzzer doesn't work, (I put it on like the service manual says to for testing, on the pressure sensor line) the spec says its suppose to go off )the buzzer and the light) under 50PSI. The spec range of the charge pump says between 90-150 PSI so... I watch the gauge. I was under the impression that midway between 90-150 would be optimal but as long as it runs about 110-120 all the time, I guess I won't worry about it. I'm not too proud to admit I have really no idea what that charge pressure is or means. All I know is the book says "between 90-150". LOL

Quote:
If there is not a low loop problem, the charge pressure is just fine.


I wouldn't know if it did... what are the signs of a low loop problem? As far as I can tell it runs perfectly fine, no struggle digging or lifting or driving. Works like a bear for as old as it is. Let me know what that is and I'll watch for it.

Quote:
I think you might need an oil with ZDDP in it.


My thinking was this thing is old, oils are different than they were back in the 70s, so what it was getting with 70s era motor oil is probably not what its getting with 21st century motor oil. Thus my questions and confusion.





You can get ISO 100 hydraulic fluid most anywhere...although now that you mention it says you can use ATF, I would steer you to a lighter grade hydraulic fluid...maybe a ISO 68 max...maybe even a 46? I would run a hydraulic fluid over a UTF.

https://www.theisens.com/products/iso-100-extra-heavy-hydraulic-fluid-2-gallons/921545/

It sounds like your charge pressure is just fine, so don't mess with it. What engine speed did you measure it at? It will be higher at higher engine speeds.

Low loop problems are hard to detect until it is too late...and you get catastrophic damage. If you are measuring it to be ok, I would not worry about it.

If you are interested in learning about your charge circuit...or any of the hydraulics for that matter, just let me know.
 
Originally Posted By: DriveHard
Run a modern hydraulic fluid of the weight equivalent to the engine oil you are using now. I think that would be around a ISO 100. That should be more shear stable...although would effect your cold temp operation if you use it during the winter very much...were you may have to switch to a lighter grade in the winter months. I would never suggest motor oil in a hydraulic system.

In a dedicated hydraulic circuit,I totally concur with the use of hydraulic oil over engine oil as it is the suitable choice.

I'm not familiar with this L325, probably OP or any knowledgeable member can point to whether the said oil is being used in this L325 Wheel Spindle And Drive Gears compartment as follows:


If the answer is:
a)no,hydraulic oils IS the suitable oils to use ; or
b)yes, choice of hydraulic oils is not suitable. Instead universal hydraulic transmission or HDEO may be used. However I would personnally prefer Transmission Oil SAE 30 meeting say, Caterpillar TDTO specifications in this context .
 
I didn't see this to reply but better late than never....

Yea the hydro oil tanks are where the drive chains and gears are immersed.

Lately the little thing has been running hot after 15 min and losing pressure from 115psi down to about 60 when it starts to get weak. I changed the oil in the tanks with new 10w40 but it didn't help. So on a lark I dumped a half gallon of MotorKote in the tanks and it runs cooler now, we rarely run it longer than a half hour but I was moving hay with it for about 90 min the other day and the pressure stayed right on 110 +/- a few # the whole time and the tanks stayed cool.

So... musta been some old age friction going on in the pumps or something. If it was ready to die I figured there was nothing to lose right? It seems to have worked fine. The drive chains seem to work quieter and smoother now too.
 
Originally Posted by nyquil_junkie

Yea the hydro oil tanks are where the drive chains and gears are immersed.
The bold suggests a requirement for a GL4 'speced' lubricants, such as :
a)conventional Manual Transmission Fluid, or
b)HDEO (which is more shear stable than PCMO's or multigrades) oils, or
c)Universal Transmission Tractor Fluids or
d)possibly some Universal Hydraulic Fluid (that claims being suitable for use in gear trains),
...... all of which above mentioned, are suitable for your hydraulic applications , and hence replacing the need for dedicated Hydraulic Oils (which in itself, without Oil company expressed claim ) is not quite suitable for the gears and chains system .

Stay away from Universal Hydraulic Fluids or dedicated Hydraulic Fluids that does NOT claim as suitable in gear trains applications ,which typically never carry a GL4 claim.

Quote
Lately the little thing has been running hot after 15 min and losing pressure from 115psi down to about 60 when it starts to get weak. I changed the oil in the tanks with new 10w40 but it didn't help.

At similar work load or output, the oil that runs hot after typically 5 - 8 hours (in your case, 15 minutes) of operation is broadly due to (unacceptable) inadequate operating viscosity . Period.

Too low an operating viscosity is likely caused by 'too high' an operating temperature than necessary/acceptable, particularly resulting from the use of 'too low' an oil viscosity grade specifically its value of KV@40*C ( not quite KV@100*C) .
Besides, a higher operating Coefficient of Friction (due to lack of friction 'reducing' additives within the oil) leads to a higher increase of oil temperature .

Quote
So on a lark I dumped a half gallon of MotorKote in the tanks and it runs cooler now, we rarely run it longer than a half hour but I was moving hay with it for about 90 min the other day and the pressure stayed right on 110 +/- a few # the whole time and the tanks stayed cool.

I do not know anything about MotorKote , but would speculate nonetheless it did NOT significantly thicken the oil, to such a degree sufficient to noticeably reduce operating temperature of the oil in this application of yours .
I believe this cooler running oil is being helped by MotorKote's friction reducing additives like Mo/Boron/Ti/AW etc .
Reduced Coefficient of Friction,likely in your context, leads to reduced generation of frictional heat/loss.
IMHO, a thick GL4 would be adequate to replace MotorKote's role .

Quote
So... musta been some old age friction going on in the pumps or something. If it was ready to die I figured there was nothing to lose right? It seems to have worked fine. The drive chains seem to work quieter and smoother now too.


I believe the cooler running oil is not substantially related to pump and its performance, not saying pump has no role in heat reduction.
Instead inadequate operating viscosity promotes pump leakage, which is a source of heat generation in the oil.

Just my
49.gif


Edit:Viscosity-related fluid drag friction or base oil-related traction coefficient is irrelevant in your 'problem' .It's about Minimum Oil Film Thickness (MOFT) .
 
Last edited:
Seems like sound advice... thanks!

The tanks are marked "use only 10w40 motor oil". But thats a 40+ yr old spec so.... ther is probably room for a better oil they didn't have back then.

Quote
I do not know anything about MotorKote , but would speculate nonetheless it did NOT significantly thicken the oil, to such a degree sufficient to noticeably reduce operating temperature of the oil in this application of yours


Motorkote doesn't thicken the oil.... the claim is it is a lubricant not an oil and all it does is somehow bewitch the metals to be..... more slippery.... a friction reducer.

Next time it starts misbehaving I'll swap all the motor oil out for a decent hydro fluid as you suggest. For now, its being its oldself again.
 
Last edited:
Status
Not open for further replies.
Back
Top