Hi all, First post !!! I have had this annoying problem with my boom lift for some time now, it is an intermittent fault and struggles to lift sometimes, more so under load, and while this is happening does not hold position in the center position and drifts down slowly....... I sometimes raise engine speed when this happens, and play around attempting to lift then lower boom then lift again quickly, this usually corrects the problem 100% until shortly after happens again........most likely happens more after max position of boom lift, sort of explaining interruption of relief valve. It is only on the lift side of the boom and holding position in the central position, once it corrects, works perfectly! I do not think it could be ram seals as is intermittent, I have removed the relief valve on the boom lift side of the spool, took it apart, looked pretty good inside, but cleaned put back on machine but problem still exists........ I know I could try swapping over relief valve from another service but was wondering if it could possibly be anything else....I don't think it could be the other relief valve on the lowering side of the boom. Any guide into getting this problem solved would be just be music to my ears........ As a side note, is it necessary to drain the hydraulic oil to work on the relief valves or is there another way......when I removed it before a good amount of oil came out.... Many thanks
Good possibility it is a piston seal, not sure if that machine has load checks in the valve sections, or in the port relief itself could be that as well. When I need to service something in a hydraulic system I have a way to pull vacuum on the tank, you just have to be careful if you pull too much oil it will overfill the tank. Sometimes a catch tank for overflow is needed. I have also had some luck in a pinch removing the tank cap and sealing the opening with cling film or thin rubber sheet, once even stretched a surgical glove over one to sort of air lock the tank, slows down the oil flow at least to wherever you open up the system.
Thanks...... I have attached a diagram of the main spool, and of the boom slice, I note that there is a kind of small check valve between each spool but not sure what this does......the actual boom relief valve I took out was just a basic adjustable relief valve, no secondary valves inside.... The valve I took out was the far left top, I assume this to be the correct one as the piping going to the bottom of the boom cylinder connects directly above this valve on same side. Hope this helps,
Good morning everyone , I have recently purchased a old kubota kx41 mini excavator and as I operate this machine in cat controls it seems to get confused between cat and john deere controls also I bought a ditching bucket that has side to side angle and this attachment is really aggressive 1 way but it won't go both ways, I'm just wondering if there's a simple fix
Check that your pattern changer is staying locked in the pattern style you require. They usually have some form of locking into position. The bucket attachment has a high flow supply one way that may require a flow control installed and you may have a 2-way valve on the machine that is set for single acting function instead of double acting. Kind regards