580K Hissing Noise

[Colonel Clank]

My 1987 580K is working quite well. (Pre JJ serial No.) It makes good power and all of the functions seem smooth and strong. However I started getting a hissing sound coming out of the rear of the machine, I believe at the backhoe control valve area. The hissing gets louder as the system warms up. It temporarily stops while moving the loader controls but then immediately returns. I suspect I picked up some dirt with one of the stabilizer cylinders which had been leaking and had a rotted wiper. I have since repacked the stabilizers and most of the other cylinders, changed the fluid and filter. I didn't expect it to go away on its own but was kinda hoping... LOL. I have the factory service manual, from which I am trying to understand the flow chart. The case parts website has some insightful diagrams too but I am new to hydraulics.

I believe I need to disassemble the backhoe control valve to clean and check for debris or damaged pieces inside. I'd love to hear your thoughts and have a couple more specific questions:
1) Does operating the FEL disrupt flow to the backhoe control valve, hence the temporary pause in the hissing sound when using the FEL?
2) Should I remove the valve body from the machine and separate each component (i.e., inlet, each circuit, outlet) or can I do one circuit at a time on the machine and blow them out with compressed air? The manual says the valve body weighs about 120lbs.
3) Is there another component I may be overlooking? I put a stethoscope on the valve body while it was running but could not determine an exact source of the noise.

Thanks,

Kevin

 

[Billrog]

I wouldn't be in a rush to remove the control unit and dismantle it. You can work on each control from the top and bottom right on the machine.
Take some time and try and isolate the area the noise is coming from can't help you because I've never had a hoe make a hissing sound relief valves only and they squeal but maybe you and a hissing one ?

 

[mitch504]

Is it not doing anything it should, or, doing anything it shouldn't?

 

[Colonel Clank]

Is it not doing anything it should, or, doing anything it shouldn't?

Mitch, the machine seems to perform fine. It just makes a constant hissing noise when running.

 

[alrman]

A hissing noise would normally indicate that there is some oil moving or under pressure.
Do the control levers all feel normal? Properly neutralised? Not binding? Foot pedal/s for extendahoe or swing included?

Also check all the spool end caps for tightness, I have seen them come loose & allow a spool not to be centred correctly.

 

[Coy Lancaster]

Try bottoming out each cylinder and see if another function tries to move, such as when you bottom out the crowd cyl. and hold it does the bucket, swing or boom move? If either one or more do then the load check O-rings are bad and will have to be replaced.

 

[jimg984]

relief valve, crimped metal tubing

 

[Colonel Clank]

Well, I'm finally getting back to the machine. Thanks for the replies. I appreciate them. Since I last posted there have been some new developments. Now the BH controls don't respond with much power and all the BH cylinders move much slower than before. I used the machine to last fall for about 16 hours. At one point the noise seemed to go away for about 10 minutes and the boom and swing controls got more responsive but then the problem got worse and I started getting some unexpected movements such as Coy advised to be on the lookout for. I suspect something moved into a new area of the valve body.

I just removed the BH control valve and swing sequence valve out and plugged up all the lines with the correct JIC plugs and caps. I brought the entire valve bodies home and I'll be taking each section apart 1 by 1 after cleaning the outsides. The control valve bodies are not super dirty and no leaks which look serious. The Boom and Swing valve caps look little wet. I'll post updates asap. I will also post when I resolve the matter in case it helps anyone else out. Thanks, Kevin

 

[Willie B]

My first suspicion is a hydraulic suction screen blocked.
I often make the point there is no such thing as vacuum. There is only a partial absence of pressure.
From the reservoir there is only a pressure differential from reservoir to pump. If the pump makes vacuum, but the screen won't allow atmospheric pressure to push oil to it, it gets gasses dissolved in the oil, or air leaking from small holes in the suction system. Pump runs with a bit of oil, makes a howl.

 

[Colonel Clank]

Anti climatic update: I cleaned and changed all the o-rings in the bh control valve and re adjusted the linkage to the swing sequence valve as per the book instructions.

In addition to the hissing in the BH control valve area, there is also a noticeable load on the motor when the machine is running and every control is centered. However, if I move the lift/lower the loader or curl/uncurl the bucket the load and hissing goes away and the engine rpms come up. As soon a I let go of the loader controls the hissing and load on the motor comes.

These are open center systems and the only thing I can think of that would cause a hissing and load would be a control valve open but everything seams to be centered properly. I really need to learn a good hydraulic trouble shooting sequence.

I made 2 youtube videos to illustrate the load and noise issue.

If the youtube links are not displayed, the channel is called PartsisParts.

 

[Coy Lancaster]

I never could adjust the swing sequence valve the way the book said to do it. I always adjusted it by trial and error. How does the boom swing, does it swing equally both ways?

 

[Colonel Clank]

It does swing equally both ways. Im going to be looking at the machine this week. I’ll take a stethascope and laser thermometer and try to pinpoint the location of the noise more precisely. Stay tuned.

 

[Willie B]

I've had two 580K, early series & close serial numbers. One was extend a hoe SAE joystick control. The other was three lever, foot swing. I couldn't learn to love the three lever unit & the machine was very low hour, in nice shape. Switched dippers & control tower, replacing pins & bushings in the process. It was a BIG job, I don't think I'd do it again.
Both machines had issues with the swing proportion valve. They get corroded & a spring breaks. Easy rebuild once you get it out of the tractor.

 

[Colonel Clank]

What were the symptoms that prompted the swing valve rebuild? I didn’t rebuild that yet. The bh control valves were quite easy. I wouldn’t take the bh control valve assembly out of the machine again either. Just change everything in the tractor…

 

[Willie B]

What were the symptoms that prompted the swing valve rebuild? I didn’t rebuild that yet. The bh control valves were quite easy. I wouldn’t take the bh control valve assembly out of the machine again either. Just change everything in the tractor…

It'd swing too fast, bang the stops swinging one way, very slow to swing the other way & wouldn't swing all the way.

 

[Colonel Clank]

To close this issue of hydraulic hissing and a drag on the engine, I found the problem.

My FEL has a 3 spool valve. The 3rd spool valve is for a clam bucket which is not installed and the lines are capped off. Somehow, the clam spool valve linkage was partially engaged and seized up, causing the valve to partially open. When I removed the linkage the load on the engine cleared up and the noise went away. Everything is back to normal now.

 

[Welder Dave]

A lot of operators don't use float on a skid steer and the linkage seizes up. It's good to move levers periodically even if they aren't used. You can do it with the machine shut off. Putting some lube on the linkage occasionally is a good idea too. Not too much so it attracts a lot of dirt.