pipe dope-type substance on screen

[devaldivia]

I've inherited a New Holland L783 skid loader from my step dad. He was a heavy equipment mechanic.

Well, after running it a couple of hours, the hydraulics started running very slowly. Took out the hydraulic screen, and it has some pipe dope-type substance clogging it up. Like that stuff you use on pipe thread instead of teflon tape. Now, knowing my stepdad, I'm sure he didn't make use of that stuff on any connections.

I found a few 5 gallon buckets of Orscheln 303 Premium Tractor Fluid. It says on the label that it's compatible with J20A Hydraulic Fluid, as specified for the skid loader .... but so far my best guess is that the fluid broke down and turned into this pipe dope-type sludge.

Anybody have any clues what could cause this and how to fix it? Am I thinking right??

I was thinking of trying to drain the fluid from the crankcase, but what would you all recommend in order to flush out the system? And how?

Also, it seems like after sitting a while, then if we run it the next day, the hydraulics will run good for a spell but after some minutes start to slow/stop again.

 

[kennyd]

What color was this substance? There is a sort of algea that can grow in hydraulic oil and clog up screens and filters, it's usually from some water intrusion in the system.

 

[Gary Fowler]

That is what I was guessing, water and possibly dirt contamination forming the white sludge. I had that in my Japanese imported grey market tractor. IT took several oil and filter changes and finally a scrubbing and flushing with diesel to get it all out. It looked like a white clay slurry and would stop up the primary filter pretty quickly. Not sure if it is an algae but it was pretty hard to get it all out of the ridged reservoir even with a 3" hole in the rear. At least on that tractor the hole was large enough to run rags up in to wipe up the sludge pockets that didn't drain with the oil.

 

[devaldivia]

Thank you Kenny and Gary for the replies.

About the substance, it's an off-white color, "white sludge" seems like a good description for it. When I scrape some off of the screen, it balls up in fingers with a rubbery consistency. It also comes out as white flakes on the bottom of the screen's rubber gasket.

Here are a couple of pictures of a clean screen- NOT this skid:


And here are a couple of pictures of the clogged screen on this skid:



Q. What color is that algae you all are talking about? Does it ball up rubbery-like?

Water contamination seems like a good theory for what happened. As my stepdad passed away unexpectedly, the skid was out in the elements, uncovered, for a number of months.

Now, to flushing it out. It is darned hard to get it out of that screen. I tried some carb cleaner but nothing doing. I'll try diesel next. Also, with this skid steer, the chain cases are the reservoir, so there's plenty in there for the sludge to get stuck on and no chance to get a rag in there to clean up- I'd have to take it all completely apart and clean each piece by hand.

Q. How do you recommend that I get the sludge out?

Q. Is there a solvent I could run in there that would scrub things, maybe also allow me to drive the skid a bit so that that the parts in the chain cases get clean?

Very grateful for any and all tips! Thanks!!

 

[kennyd]

Here is a good article I found: Get the drop on water | Pneumatic Valves content from Hydraulics & Pneumatics

The first indication of microbial contamination may be a foul odor that comes from waste and decomposition products of the microbes. Fluid viscosity may increase due to the mass of material produced by these organisms. At the same time, the fluid may have a brown mayonnaise-like appearance, or slimy green look.

I think I would get a fluid sample next, and send it off to a place like Blackstone Labs for analysis, then you might have a better idea of what your dealing with.

 

[devaldivia]

Thanks Kenny, good article there.

Regarding that quote on the "brown mayonnaise-like appearance." The hydraulic fluid is not all that color, just what's stuck on the screen (plus anything that might be stuck on other surfaces inside). Unfortunately, I haven't had a good look at the fluid itself, but what I saw sitting in the screen tank seemed pretty normal. Might try looking at it more closely tomorrow.