Yanmar SA424 possible water contamination in Hydraulic Fluid

[BCLoco]

I'll pay more attention to how mine reacts cold this Sunday. It's going to be in the -20s, so should be as good a comparison as any.

-24C here yesterday. I checked the hydraulic functions during the first minute or so of operation and found that although the hydro motor and main pump were as whiney as ever when they're that cold, the cylinder functions all worked basically normally. Including three point hitch lift. The steering assist was a different story, but after about a minute of running, it too was more or less functioning normally.

I still let it run for at least 10 minutes before even moving it. Putting my hand on the hydraulic feed connection at the loader valve, I can start to feel some temperature increase. Ultimately it's how the pump sounds that tells me if I need to give it more time. One of these days I'll put a temp gun on there and measure how long it takes the fluid to get to 5C from those temperatures. I'd like to actually know if I'm wasting time, or if it could use a bit longer of a warm-up.

 

[Hulaballoo]

So I imagined that I'd have more time to work on the tractor, then life happened. I've been mostly out of town for the past couple weeks and down with the flu for the rest. But during a brief period of time at home and upright, I put in warm fluid, gave it some time to settle then started it up (this was before reading the advice to run a single cylinder in only one direction.... I let it warm up a few minutes, then I cycled the stabilizer legs in both directions.

After running great initially, the engine began to slow down, and would not react to the throttle at all. Once I could tell it wasn't happy I stopped cycling hydraulics. Ultimately it stalled and would not restart. My first thought was perhaps most of the tank was summer diesel and it gelled; It was pretty cold when I tested, but having the hyd. fluid warm when I poured it in, made me feel good enough to test despite the weather. I did add stabilizer to that 5 gal can of fuel, but don't remember if I added an anti-gel additive.

The other thought came to mind after seeing a warning placard to take the machine to the dealer if it ever tips over and not to attempt a re-start. I have no idea why this would be necessary, but am 100% certain that I'd be asking advice in a place like this before winching the machine to a flat bed and bringing it in. Could it be that too much air in the system (like if the tractor inverted), (or if the owner tried to outsmart the manual and drain contaminated oil from every conceivable hiding place by emptying cylinders that should be full of fluid) could make the pump so difficult to turn that the engine would stall? I look forward to hearing your theories. It's worth mentioning that the engine has always run flawlessly up to that point.

As luck would have it I'm out of town again, so can't try anything until the weekend. But it should be in the 50's(!), so I can rule out the gelled fuel theory.

P.S. Yes, the oil looks terrible. It looked much cleaner through the small sight glass, and before I aerated it in operation.

 

[Hulaballoo]

While I patiently await a reply to my main problem, I'll ask a distantly related question, as I'm hungry to learn about my machine, and Yanmar doesn't make it easy.

As far as I can tell, my tractor has two hydraulic motors... Does this make sense? But it certainly only has one reservoir. All functions, from steering to FWD/REV drive power are hydraulic, so perhaps having multiple motors makes sense. I also see two Hydraulic filters on my machine, but the manual only calls for changing one of them (the bigger one) in the maintenance section. I sourced the smaller one and changed that too anyhow, but it's curious that it isn't mentioned at all in the manual.

 

[bmaverick]

I removed and drained the filters, then reinstalled. I've got 5 fresh gallons of Traveller brand (J20c compliant) fluid staying warm indoors, and hope to go outside this afternoon to pour it in.

The TSC Traveller brand had/has been in a class action lawsuit damaging plenty of Mitsubishi, Kubota, Deere and Yanmar machines for being 'compliant', yet NOT 'meeting' JDM J20C.

The only TSC fluid to 'meet' the JDM J20C (Hygard Deere or TF500A Yanmar) is their Premium Traveler brand.

This product was originally made to FLUSH out water out of the hydraulic system and fuel systems of diesel machines. Drain out the bad fluid, next add 2 bottles to a 5-gallon bucket of diesel fuel, and pour it into the fill port for the hydraulics. At low 1,200 rpms, keep working the 3-point and hydraulics. Work the fluid around. If the hydraulics is used to move the machine, work all gears forwards and back. Then drain and refill with the JDM J20C or TF500A fluid.

 

[Hulaballoo]

I'll have to check to see whether I got the "premium" fluid or not. Probably not, as I was buying cheap stuff since it likely won't be in the machine long. Hopefully it won't do much damage in the short time it will be in there. Thanks for the heads up.

So you're suggesting that I add Seafoam to DIESEL fuel, then fill my hydraulic reservoir with it, drain it then add hydraulic fluid and all will be well? Interesting idea. Certainly would be cheaper than repeatedly flushing with $80 buckets of hyd fluid. I've seen the "removes moisture from oil" ad before, and have wondered how that worked.

 

[rScotty]

So I imagined that I'd have more time to work on the tractor, then life happened. I've been mostly out of town for the past couple weeks and down with the flu for the rest. But during a brief period of time at home and upright, I put in warm fluid, gave it some time to settle then started it up (this was before reading the advice to run a single cylinder in only one direction.... I let it warm up a few minutes, then I cycled the stabilizer legs in both directions.

After running great initially, the engine began to slow down, and would not react to the throttle at all. Once I could tell it wasn't happy I stopped cycling hydraulics. Ultimately it stalled and would not restart. My first thought was perhaps most of the tank was summer diesel and it gelled; It was pretty cold when I tested, but having the hyd. fluid warm when I poured it in, made me feel good enough to test despite the weather. I did add stabilizer to that 5 gal can of fuel, but don't remember if I added an anti-gel additive.

The other thought came to mind after seeing a warning placard to take the machine to the dealer if it ever tips over and not to attempt a re-start. I have no idea why this would be necessary, but am 100% certain that I'd be asking advice in a place like this before winching the machine to a flat bed and bringing it in. Could it be that too much air in the system (like if the tractor inverted), (or if the owner tried to outsmart the manual and drain contaminated oil from every conceivable hiding place by emptying cylinders that should be full of fluid) could make the pump so difficult to turn that the engine would stall? I look forward to hearing your theories. It's worth mentioning that the engine has always run flawlessly up to that point.

As luck would have it I'm out of town again, so can't try anything until the weekend. But it should be in the 50's(!), so I can rule out the gelled fuel theory.

P.S. Yes, the oil looks terrible. It looked much cleaner through the small sight glass, and before I aerated it in operation.

The motor gradually dying is a typical symptom of a fuel filter that is pulling in gelled fuel - as the fuel filter becomes progressively plugged with wax and gel. Easiest to just replace the filter. Now is the time to add some serious anti-gel to the fuel tank. Having a bit too much anti-gel won't hurt anything.

50/60 degress F may not be enough temperature to deal with gelled fuel. Don't feel bad, I had some fuel gell on me in our tractor last year in spite of 50 years experience. There is no commercial test for diesel fuel gel point - called "cloud point" - although it is simple to test yourself.
Once it has gelled or has "waxed", there are plenty of articles here on TBN on what to do. Last year on mine I used Power Service 911 and followed that with John Deere TY26787 winter fuel conditioner and de-icer. Be generous with the dose. It may take a few days of near summer temperatures even with the 911. .

Regarding the transhydraulic oil. Your's will most likely be OK. Open center type hydraulic systems can handle some water because of the fluid emulsification additive and because any extra tends to end up at the bottom of the sump and filters.
Sure, take the hyd filters inside...thaw them out, check the gasket and reuse. If yours has more than one filter keep the order the same.

BTW, I used JD HyGard Lo Viscosity in my Yanmars. At one time it was recommended by Yanmar. You want to get the Lo Viscosity HyGard for your/our climate. Most of the trans/hydraulic fluids - even the name brands - do not offer a low viscosity. Yes, HyGard is miscible with other trans/hydraulic fluids. I live in the Colorado mountains and the regular viscosity JD HyGard is just too viscous for our climate.

Travelers is OK as a warm weather flushing oil, but you may flush better using a lower viscosity fluid.
If you read up on what the advertising term "compatible with" really means on cheap trans/hydraulic fluid, you will probably want to end up with a name brand trans/hydraulic fluid in your tractor in spite of the cost.
Yanmars are too nice and precision to risk for pennies.
Enjoy,
rScotty

 

[rScotty]

While I patiently await a reply to my main problem, I'll ask a distantly related question, as I'm hungry to learn about my machine, and Yanmar doesn't make it easy.

As far as I can tell, my tractor has two hydraulic motors... Does this make sense? But it certainly only has one reservoir. All functions, from steering to FWD/REV drive power are hydraulic, so perhaps having multiple motors makes sense. I also see two Hydraulic filters on my machine, but the manual only calls for changing one of them (the bigger one) in the maintenance section. I sourced the smaller one and changed that too anyhow, but it's curious that it isn't mentioned at all in the manual.

No, did you mean to call them hydraulic motors??? Or do you mean hydraulic pumps?

Uh....Here we are ignoring that a hydraulic motor and are hydraulic pump are pretty much the same physically - one is turning a shaft in response to hydraulic flow and the other works exactly vice versa.

It is common for tractors to have more than one hydrauic pump. Our Kubota has four, and one is a "piggyback" with two rotors on a central shaft that extends through parallel pump body castings. So your Yanmar could certainly have several. Or piggybacks.

Tractors with HST transmissions also have a couple of hydraulic pumps (and motors) within the transmission itself....but we don't count those.

The larger main system filter is generally a suction type. Those tend to have fairly thin walls on the cannister and weigh about what you would expect for a filter that size.
Just guessing on the small filter, but some tractors have a smaller micron passing rating "bypass filter" that filters a small amount of fluid for critical areas.

Smaller "bypass filters" are sometimes running at slight positive pressures - they do that so that they can filter smaller particles through special filter media having smaller pores. That means they have to have heavier construction to handle some positive pressure and will be surprisingly heavy - and more expensive.

If you have a shop manual for your Yanmar it will have a hydraulic schematic. If you do, and want, you can post the hydraulic schematic and we can go through that with you. It will answer at least some of these questions.
Luck,
rScotty

 

[bmaverick]

I'll have to check to see whether I got the "premium" fluid or not. Probably not, as I was buying cheap stuff since it likely won't be in the machine long. Hopefully it won't do much damage in the short time it will be in there. Thanks for the heads up.

So you're suggesting that I add Seafoam to DIESEL fuel, then fill my hydraulic reservoir with it, drain it then add hydraulic fluid and all will be well? Interesting idea. Certainly would be cheaper than repeatedly flushing with $80 buckets of hyd fluid. I've seen the "removes moisture from oil" ad before, and have wondered how that worked.

Once the diesel and 2-bottles of Seafoam are in the system, drive the tractor around at the 1200rpms and move anything with the controls for the hydraulics. This way, the water is captured and so is the bad fluid gunk. Then drain.

When we see Yanmars, Deeres, Cub Cadets in a bad way for hydraulics, this is our go to for cleaning the system. Both diesel and Seafoam have lubrication properties too, so nothing in the cleaning will be harsh on the gears, pump(s) or lines. Just keep the rpms low to avoid heat and friction as diesel and Seafoam are thinner in viscosity.

 

[bmaverick]

I'll have to check to see whether I got the "premium" fluid or not. Probably not, as I was buying cheap stuff since it likely won't be in the machine long. Hopefully it won't do much damage in the short time it will be in there. Thanks for the heads up.

So you're suggesting that I add Seafoam to DIESEL fuel, then fill my hydraulic reservoir with it, drain it then add hydraulic fluid and all will be well? Interesting idea. Certainly would be cheaper than repeatedly flushing with $80 buckets of hyd fluid. I've seen the "removes moisture from oil" ad before, and have wondered how that worked.

And if you live in higher altitude and colder winters like @rScotty Hygard JDM J20D is the way to go.

 

[BCLoco]

So I imagined that I'd have more time to work on the tractor, then life happened. I've been mostly out of town for the past couple weeks and down with the flu for the rest. But during a brief period of time at home and upright, I put in warm fluid, gave it some time to settle then started it up (this was before reading the advice to run a single cylinder in only one direction.... I let it warm up a few minutes, then I cycled the stabilizer legs in both directions.

After running great initially, the engine began to slow down, and would not react to the throttle at all. Once I could tell it wasn't happy I stopped cycling hydraulics. Ultimately it stalled and would not restart. My first thought was perhaps most of the tank was summer diesel and it gelled; It was pretty cold when I tested, but having the hyd. fluid warm when I poured it in, made me feel good enough to test despite the weather. I did add stabilizer to that 5 gal can of fuel, but don't remember if I added an anti-gel additive.

The other thought came to mind after seeing a warning placard to take the machine to the dealer if it ever tips over and not to attempt a re-start. I have no idea why this would be necessary, but am 100% certain that I'd be asking advice in a place like this before winching the machine to a flat bed and bringing it in. Could it be that too much air in the system (like if the tractor inverted), (or if the owner tried to outsmart the manual and drain contaminated oil from every conceivable hiding place by emptying cylinders that should be full of fluid) could make the pump so difficult to turn that the engine would stall? I look forward to hearing your theories. It's worth mentioning that the engine has always run flawlessly up to that point.

As luck would have it I'm out of town again, so can't try anything until the weekend. But it should be in the 50's(!), so I can rule out the gelled fuel theory.

P.S. Yes, the oil looks terrible. It looked much cleaner through the small sight glass, and before I aerated it in operation.

When you say it wouldn't restart, do you mean it was cranking but not starting? Or not cranking, like just a click when the key was turned to start position?

If it was cranking but not starting, likely a fuel issue. Warmer weather may or may not be enough to get fuel moving again. Regardless of what it takes to get it started (filters, anti-gels, etc.), make sure it's running on winter diesel.

If the engine was not cranking after it stalled, or cranked very slowly, then that is another issue entirely and possibly bad news.

The advice about not attempting to start after rollover is due to the risk that engine oil leaked past the rings and into the combustion chamber/swept portion of the cylinder. If this was the case, attempting to start it could cause hydraulic lock and serious engine damage. Nothing for you to worry about in your situation.