I completed my trenching bucket and went to use it today. I trenched about ten feet then the curl wouldn't work under pressure. I also noticed the crowd wouldn't work under pressure either. When no pressure out of the trench they worked fine. Do you think it's in the cylinders leaking by internally or the control valve?
Yes Tim the boom, down riggers and the left and right swing appear to work fine. It started to rain so I stopped the trenching for today. I'll try it again soon and give an update. I know there is enough oil in the tank and it only was under stress that it seemed to stall. No noise it just stopped curling.
In my mind attempting to diagnose this, what is common to those 2 cylinders? If the rest of the tractor and hoe works and has power, it would be really odd for the seals in two cylinder to fail at the same time.
Go to page 14 this loader valve there 3 caps from right to left close to spool third single cap to left one has broke spring are stuck open relief. its spring item 18 it maybe trash holding relief open you find trouble there. on bottom valve has same.
I tried the backhoe again last week and it wouldn't curl, so i decided last weekend to check the relief valves on the backhoe. I did find a little spouge in the one valve and some sediment in the bottom of the valves, no broken springs. I tried the backhoe out this morning and it worked like a champ, no hesitation or stopping. The dipper also seemed to work great.
I'm digging some dirt in my backyard, using it to fill in low spots and then plant some grass for a fall planting. It's creating a low spot in the back which will fill in with water from the winter thaw. I'll post some pics the next time I'm using the backhoe.
A big thank you to Gator for giving me the manual link and the suggestion how to fix my situation.
Yesterday I was using the backhoe to move some dirt and the bucket suddenly wouldn't dump. All other functions for the backhoe appeared to work fine. When activating the dump lever the bucket starts to move but it appears to be struggling to the point that the engine will stall out. I removed the relief valve again and checked for a broken spring or dirt and found nothing. It seems like there is a restriction in the hydraulic hose so the oil won't flow to retract the cylinder ram. Any suggestions out there? Maybe it's time for a cylinder rebuild!
Harry, my guess is that hose interior failure is letting debris plug return ports. I would probably remove the return line at or near the valve and watch for flow. It should be and indicator of plugging at the valve or of a cylinder rod failure.
I spent 4 days tuning a system last week. It had 15 years of no maintenance, no filter or oil changes. Even in a closed system it was incredible how much rubber was packed in the filter and cylinder ends. System would run about 2 hours before stalling due to temperature rise, oil breakdown, and filter plugging.
Your issues are an encouragement for me to do a complete and thorough rebuild on my 646B hydraulics before painting.