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Boom drifting
- Thread starter Ejp
- Start date
Toolslinger
Well-Known Member
Need to repack the cylinder most likely.
Toolslinger
Well-Known Member
Did they do the rod, or just the gland on the end? It would be weird to not do the whole thing, but anything is possible.
Otherwise, IDK... Failed relief possibly? A worn spool woudn't just suddenly happen.
Otherwise, IDK... Failed relief possibly? A worn spool woudn't just suddenly happen.
pittsburgh cat man
Active Member
I would hold the boom up with the stick then cap off the cylinder, move stick and see if cylinder holds if it holds problem is in valves
I might have misspoke on my first thread as to the time it drifts down, it takes about 4 to 5 minutes to go from full up to full down.
Iam not sure what they did do but it stopped the leak on the outside of the rod. I am not sure if it had a slight drift to the boom at that time. My main concern was the leaking of oil on the outside. if the gland was bad, wouldn’t that make it leak on the outside of the ram?
pittsburgh cat man
Active Member
remove both lines cap the side that will have the load on it if it is leaking at piston it will be forced out of the other line
I think I understand it now I may put a hydraulic jack under the boom stand and then release that if you think that’s a good idea ,at any rate, I won’t be able to get to it for several days, but I definitely will do that and I want to thank both of youse for the help that you’ve given me and I’ll get back to you on the outcome. Thanks again.
willie59
Administrator
I'm not familiar at all with a 1966 Deere backhoe, but if the drift isn't caused by a faulty cylinder then the problem would have to be in the valve. Again, I don't know this backhoe, but most backhoe type control valves have port reliefs for extend and retract functions, you could have a faulty port relief valve. I don't know if yours does or not, but if it does, rest the boom/bucket on the ground to relieve load and find a way to swap the hoses going to the boom cylinder, might have to make up a hose or two to do this. Once you get the hoses swapped, raise the boom, which would now be the boom down on the control stick, see if it still drifts down.
Welder Dave
Senior Member
I wouldn't think a shop would only replace the gland nut seals. When was the hyd. filter/oil last changed? If the oil was a little contaminated might have caused the internal cylinder seals to leak. That's the problem the majority of the time. If you pick up the machine using the backhoe boom does it also creep down?
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Dave I did as you said I lifted the back of the backhoe up with the with the ram left it for 15 minutes and it never drifted at all that sounds like good news for the cylinder, but is there some bad news coming?
If you are referring to the filter under the tractor hydraulic filter, it hasn’t been changed in quite some time because my leak was so profuses that I thought I was constantly putting fresh oil in it every time I used it , maybe you are talking about a strainer or something else in a different part of the tractor that I don’t know about. The leak that I was referring to was coming from a faulty O-ring in the main pump in the front of the tractor. I sense fix that and it is not leaking any longer.
Welder Dave
Senior Member
There should be a filter that is much finer than a strainer. If it didn't creep lifting the tractor means the cylinder seals might not be the problem. Make sure the linkage and spool for the boom lift moves freely and isn't binding and returns to neutral position. You could swap hoses as Willie suggested above to see if the cylinder creeps while lifting the back of the tractor. It's also possible the leak you have is on the boom lift side. If say the hose/hyd. flow going to the lift side of the boom cylinder is leaking would/could make the boom creep down because it isn't holding the pressure.
willie59
Administrator
No. Most control valves like that have port relief valves for each function, boom up, boom down. They are independent of each other. If you confirm the cylinder is not the problem, and it's drifting down instead of holding the boom up, then the circuit that raises the boom might have a faulty port relief. To test that, assuming the boom down port relieve is not faulty as well, simply swap the hoses at the boom cylinder. You'll still be booming up/down, but the control will be backwards, up is down and down is up. This way, when you raise the boom you're doing it with the boom down circuit and the boom down circuit port relief. If it holds, the port relief for boom up is likely faulty.
Welder Dave
Senior Member
I was thinking if the hyd. lines for the boom lift were leaking switching hoses might be able to rule out the cylinder.
OK I just came in from the backhoe and I reversed the boom hydraulic lines, and this is what I found first I lifted the back of the tractor with both wheels, eight or 10 inches off the ground, the drift was very light approximately 1 inch every minute with the tractor up so I then put the wheels back on the ground and extended the bucket full out and the drift was only a quarter inch every possibly 15 to 20 minutes. what are your opinions? This might sound stupid or even funny but that little bit of drift really is so much better,that it wouldn’t bother me to reprogram my brain and run the boom backwards or should I say it in reverse order?
willie59
Administrator
Dangit, how can i not explain this. Swap the lines to the cylinder. DO NOT "raise the tractor off the ground". Instead, boom it up, just like you have been doing and getting drift down while supporting the boom. The lines are reversed, you're now putting pressure on what used to be the boom down circuit before you did the hose swap, that's what we want to do to see if we get a different result. Raising the tractor off the ground doesn't tell us anything.
Hi Willy, I’m sorry I didn’t mean to goof things up. I don’t think I quite understood all of that but at any rate, I did leave it with the boom up and the bucket extended so I would be able to see if it held any during the night or if it lost all the drift.