580 Super K Hydraulic question

[Ronald Edmon]

1993 580SK with the clam shell bucket. Sprung a leak on the left hand cylinder. Squirting out the top, the fluid was a milky grey color. Checking the reservoir, fluid is clear. I was thinking I would dump the hydraulic fluid when I saw the milky color squirting out of the top of the cylinder, but with the reservoir showing clear, I don't know what to make of it. Could the milky color be isolated to the bad cylinder?

Should I be checking anything else for confirmation that a hydraulic oil change should be done? 33 gallons of hydraulic fluid is a quick $300.00 that I don't want to spend if not needed. Any help or suggestions is appreciated.

If I need to change the hydraulic oil, what is the best way to flush the system before refilling? I do have two of the hoses off of the outriggers right now for replacement (1 on the left and 1 on the right sides), along with 1 of the hoses on the clam shell cylinder. As a home owner on 10 acres with this backhoe, I don't have any experience on maintaining this beast so your knowledge would be a great help.

Thanks
Ron

 

[Vetech63]

Working a hydraulic cylinder back and forth is not circulatory. If it is grey looking it could be aluminum in the oil on that cylinder. I would think you could remove the connections of those cylinder hoses, as close to the control valve as you can, and flush them with solvent and air. A little of that could possibly get into your return system but I would think it would be a small amount.

 

[Tinkerer]

I'm surprised the reservoir is clear.
Leaks around the rod ?

 

[Ronald Edmon]

Yes, the leak was around the rod.

I will go back to the control valve and disconnect and flush with solvent . I thought a milky fluid would be considered contaminated with water, but I don't think that is possible with the reservoir being clear. I will capture the fluid when I flush it out to see exactly what it looks like.

 

[fpgm04]

Ron,
Having just gone though pulling both of my 580 Super K claim cylinders this winter, here is a few points for your consideration.

If you going to flush the claim circuit, you will need to open both the left hand and right hand cylinder sides as they are plumbed together. Flushing to just one cylinder will not fully clear out that hydraulic circuit.

You may find it would be easier to flush by breaking open the hoses by the main loader arm pivot. They are easy to access by the door.

Above all, be careful opening hydraulic circuits as they can be under pressure and also the claim, bucket, or loader can move when the circuit is opened.

For what it is worth, I did not have any milky oil in mine. However, I did not have a full fledged leak like you are describing. I simply was doing proactive maintenance this winter as my cylinders were just starting to be wet.

Also, how are you determining the reservoir is clear? By the sight glass on the side of the chassis? By taking an oil sample out of the tank? Other?

 

[Ronald Edmon]

Fpgm04,
I am glad you mentioned that left and right cylinders are plumbed together. I would have missed that more than likely. I will open the hoses by the main loader arm pivot through the access door. I was looking at that yesterday but wasn't sure. Glad you spoke up.

Yeah my seals were bad as I had a geyser spraying when I went to grab a downed oak tree using the clam shell. The broken seals must have let water into the cylinder causing the milkyness of the hydraulic fluid.

I did determine that the oil in the reservoir was clear by looking at the sight glass on the side of the tank. I opened the fill cap on the reservoir tank today but it has baffling internal and didn't try to snake a poly tube down to draw a sample. Should I try that way to get a sample to confirm, or is there another way to draw a sample?

Thanks so much

Ron

 

[JBrady]

On my Super L, there is a screen on the hyd tank fill port that can be removed with a single screw. I'd bet your Super K is similar, if not identical. From there, you can do as you suggested by inserting a piece of tubing and putting your finger or thumb over the open end to draw a sample. Dump that into a jar and let that sit for a while to see if you have any water/oil separation.
When or if you decide to change out all the fluid, read your operators manual or search on this site about making sure your hyd pump is primed. The hyd tank sits lower than the pump so it won't gravity feed the pump. The tank is slightly pressurized to force oil to the pump.

 

[Tinkerer]

From the SK manual.
Often overlooked because of it's location.

 

[Ronald Edmon]

JBrady,

Thanks for the info, I will look at that tomorrow and hopefully it will be the same. I definitely want to confirm the contents of the reservoir to what I am seeing in the sight glass.

Tinkerer, thank you for the photo from the manual.

Ron

 

[Ronald Edmon]

Now for the rest of the story: Pulled a sample of hydraulic oil from the reservoir (No screen in the top, angled shot into the tank. Got a clear silicone tube in there and pulled a sample). Sample was clear so I flushed the lines by disconnecting hoses on the cylinders since the left side was already off. Installed the seals, and everything working great. Thanks to everyone who provided information and suggestions. Made the job easier for sure.

Ron

 

[Tinkerer]

Nice to read all is good, Ron.
Just curious if you cleaned the screen in hydraulic pump suction line. The one I posted an image of.
I have seen one plugged so badly that it ruptured and was allowing contaminates to go into the pump.

 

[Ronald Edmon]

Yes I did, it needed it for sure.

Ron

 

[Blademandan]

Getting ready to do this fluid change. Wondering what could plug the screen? Someone leaving the fill cap off for debris to get in?

 

[Tinkerer]

Welcome to HEF, Blademandan !
It is amazing what I have found in screens. Usually pieces of deteriorating hose lining, metal particles from normal wear on the pump and other stuff.
Crap that got in thru the oil tank filler hole.

 

[Blademandan]

Thank you for the welcome Tinkerer. I will pull the screen and clean it with the oil change this time. Obviously more important than I thought to clean with every service. Dan