boovuc 1,090 #1 Posted November 22, 2015 Can anyone tell me how to adjust the down pressure on my boom, (not the bucket), on an original Ark Loader hydro valve? Everything works as it should but, after I had it to a local shop for a cylinder rebuild, they said they adjusted the lift valve. Well........they did and it raises just fine. When you let it down though, it rocks like crazy! You can't do any fine operation with it at all. Even if you gently open it to lower the booms. Thanks in Advance! Share this post Link to post Share on other sites
wallfish 18,108 #2 Posted November 22, 2015 Sounds like you might still have air in it but that only takes running it up and down a few times to clear it out. Make sure the oil is full because once you push all the air out and fill the cylinders, the level will drop quite a bit from the initial fill level. Run it, check the level, run it check it and do that a few times. Most of the oil is used when the loader is up and the bucket facing down so it could be possible to suck air in while lowering it if the oil is low. The same valve works both up and down so adjusting the relief pressure will affect both directions. I'm no hydraulic expert but don't think you can do any adjustments to a single side of a spool inside the valve. You can do it by adding components. . Share this post Link to post Share on other sites
elliot ness 1,916 #3 Posted November 22, 2015 Sounds like an air problem to me, probably caused buy low level of fluid in reservoir. Share this post Link to post Share on other sites
MalMac 1,332 #4 Posted November 23, 2015 Make sure you check oil with cylinders pulled in. 1 Share this post Link to post Share on other sites
boovuc 1,090 #5 Posted November 23, 2015 I ran the cyl, (bucket and boom cyls), up and down so many times it isn't funny. The level in the reservoir is good with both cylinders extended and all of them pulled in. I have no foaming in the oil either. It does it regardless if the oil is full hot or just warm. I'm wondering if maybe I have an obstruction or if my return line to the pump is collapsing and causing the jerking motion? I'm wondering if anyone else had this where it wasn't an oil level issue or a foamy hydro fluid. Share this post Link to post Share on other sites
MalMac 1,332 #6 Posted November 23, 2015 There is always a chance for a hose collapse. Sometimes they collapse internally and you can not see it. Also check any quick couples. Sometimes they fail and will not let oil flow as it should. Share this post Link to post Share on other sites
