Colonel Clank
Member
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
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