DEF in hydraulic fluid

[youngbuck007]

Our company has a CAT 262D skid steer. Thinking that all the D series have DEF fluid tanks, one of our guys topped off what he thought was the DEF tank but was actually the hydraulic fluid tank. The D machines under 75hp do not require DEF.

About a gallon went in the tank and machine did run for awhile afterwards. To be clear, it never stopped performing while in use. Once we saw the milky fluid and realized the error, we drained the tank, changed the filter and installed fresh hydraulic fluid. But problem is draining from the tank only gets about 85% of the fluid out. We can already see the new fluid is milky in color because we couldn't get all the contaminated fluid out. Is there an easy way to drain everything out? Or should we just keep changing like we've done until it looks better?

 

[Tinkerer]

Easy way - no. It will take a semi load of fresh oil if you just keep draining the tank and refilling it.
All the cylinder hoses need to be removed at the cylinders. Then the cylinders need to be manually and completely retracted and then extended to clear them. All the lines need to be flushed while still disconnected and all the while constantly keeping the hydraulic tank full.

 

[Birken Vogt]

I would be afraid even after running cylinders in and out. This stuff is pretty corrosive.

I wonder if there is some kind of polishing filter that could be installed for a week or so to strip out any water-containing substances. Then change the oil one more time to be sure.

 

[digger doug]

Every modern piece of equipment I have every laid eyes on, has every filler CLEARLY marked....


Firing is in order.

 

[youngbuck007]

Yeah I hope it's not that bad. I'm no expert by any means. From what I've read DEF is about 2/3 de-ionized water and 1/3 urea. And urea is basically ammonia and carbon dioxide. It would be great if there is some sort of super scrubber or filter, or even an additive to help dissolve or neutralize the stuff.

 

[Delmer]

... And urea is basically ammonia and carbon dioxide...

And Cyanide is basically carbon and nitrogen, but that doesn't make it harmless. Like Birken, I'd be much more worried about the urea than the water. You can see the water, but the urea is what will do the damage. Urea is a solid (common fertilizer) that is dissolved in water making DEF.

My best guess is urea has to be washed out of the oil with water, that is, ADD water to the system, mix it up, drain the oil, drain off the water/siphon off the oil, refill and repeat. When the water comes out with no trace of urea, then you could remove the water from the oil by absorbant filters, heat or vacuum dehydration. Easy for me to say, huh?

Another couple oil changes will probably work too, and/or disconnecting the lines to get more of the oil, or just retracting the cylinders to drain more when you change the oil.

 

[youngbuck007]

Thanks Delmer, definitely makes sense and certainly didn't want to make it sound like it wasn't a big deal...although sure would be nice if it wasn't right haha! We did have all the cylinders retracted when we changed it last time. We'll probably just change it a couple more times with everything retracted and disconnect the lines to get more out this time. I figure that assuming it is all evenly mixed throughout the machine (and by the uniform color we are seeing when it drains it appears to be so), if we get 85% of the contaminate out each time, after a few times there shouldn't be too much left. Still a bummer for sure, and definitely a lesson learned! We will be putting a lock on the hydraulic tank filler cap so only authorized guys have access to it.

 

[92U 3406]

We had someone fill up the hydraulic tank with diesel last week on one of our machines. At least they caught it and had the sense to not start the machine after they noticed the error.

You pretty much have to drain all the components and hoses if you can. The goal is to remove as much contaminated oil as possible.

 

[Delmer]

I meant drain the oil, then move the cylinders with another machine etc. That will empty the working volume of oil in the cylinders.

I think you're probably changing more like 60% by draining it, maybe 80% with moving the cylinders, and 90% by blowing the lines out to. Flushing with new fluid like Tinkerer said doesn't waste as much fluid, it's just the time to do it.

 

[Tinkerer]

We'll probably just change it a couple more times with everything retracted and disconnect the lines to get more out this time..

Read the advice that is given here.
Retracting a double acting cylinder will still leave a cylinder barrel full of contaminated fluid.
The cylinder has to be cycled completely both ways. to empty it.
I would use clean oil on the closed end to eject the crap out the other end.

 

[hvy 1ton]

DEF is highly corrosive and can completely destroy hydraulic systems. I know of a quadtrac that had they entire hydraulic system replaced b/c of 2.5 gallons of DEF in a much larger system. It's not just some water in the oil.

 

[DIYDAVE]

My advice would be to fire the goof, then drain out as much fluid as possible, as many times as possible, then ship the unit to a disreputable auctioneer. There's one, in seven valleys pa, that I'd send it to...

 

[DoyleX]

Think about your attachments... Do they now have a STD?

 

[Brodiesel]

It seems like DEF in the wrong tank is becoming an ongoing issue for all of California. We had a few gallons pumped into our wood chippers fuel tank and the engine started to run bad then it died and wouldn't run at all. We decided to drain the fuel tank and thats when all the "water" started to drain out, we thought it was just condensation from over the years and the pickup tube wasn't reaching the bottom of the tank, so we just wrote it off as that. Then we looked at our monthly fuel bill and thats when we saw the charge for 3 gallons of DEF, we don't run DEF in anything we have, one of the guys accidentally pumped some in one morning. Short story long.

 

[Brodiesel]

Don't fire the guy, **** happens and sometimes you have to learn the hard way.

 

[Junkyard]

For a contaminated system they do make clean out filters and you can run a system through a filter cart hooked up in various places and run various ways to clean things up. That being said I don't know it it will remove the urea from the system and stop any corrosive activity. Need a chemist to come up with a remedy for this. It's becoming more common than it should be. Maybe it's like corroded battery terminals, just throw a couple cans of coke in there .

Seriously though, it's a contaminant that may be harder to remove through conventional methods.

Junkyard

 

[Birken Vogt]

I don't know how soulble in oil it is but probably the water holds 99.9% of it.

I would install a clean out filter as stated above and work it a shift or two. Hopefully stripped out all the water by then.

Then change it with fresh oil as much as is easy to get and work it some more to get it all mixed up.

Then sample and see what the lab says. I am sure they are getting used to this as well.

 

[RZucker]

Don't fire the guy, **** happens and sometimes you have to learn the hard way.

Maybe teach him to read and comprehend what he's reading? Personally I'm sick of the "wrong fluid... wrong hole... thing". Either hire a full time oiler, or do it yourself every morning. I've been on both ends of the stick. And with the price of equipment and components these days, "**** happens" don't cut it with me if the guy just cost me $15k. He can go "learn" somewhere else.

 

[92U 3406]

Maybe teach him to read and comprehend what he's reading? Personally I'm sick of the "wrong fluid... wrong hole... thing". Either hire a full time oiler, or do it yourself every morning. I've been on both ends of the stick. And with the price of equipment and components these days, "**** happens" don't cut it with me if the guy just cost me $15k. He can go "learn" somewhere else.

I kinda have to agree. We all make mistakes but its not like the tanks aren't labled or anything. Any new Cat stuff we have, fuel cap is green, hydaulic cap is black and DEF cap is blue. The caps have obvious symbols for what they're for embossed right into the plastic. But then again we have dummies working up here that think a battery has 2 negative terminals if the sheathing on the positive cable is black rather than red (true story).

 

[toslow]

We had that happen on a 972 loader, not in hyd sys but in the fuel. wiped out the pump and injectors in no time at all.

When it came time ti fess up who done it, got the same old story wasn't me and i didn't do it.