Have my Case at local dealer for repair and getting nowhere....Hesitation started suddenly runs about 2 seconds during cycle its the blade and the arm. I run a 3' bucket never ran a hammer or larger accessories, we have checked cylinder, pump pressure "to what the dealer has" they said they do not have pressure requirements based on RPM from Case.. Really not getting any help from dealer mechanics. Any one experienced this? Any help would be great.
I need a better description of hesitation.
video of excavator sticking Thank you so much for an interest! I linked a short video that shows bringing the arm in and it will stick or hesitate then come on in. The blade is doing the same, I wish I had a little confidence in the mechanics working on it but they had to call us about where to find the conflux valve in the manual.
I don't have sound on my computer. Is the machine running at full throttle?
Sorry, this was running about half throttle....but it does it at full throttle also. The mechanics called today and said the arm is now only doing it on low throttle but the blade is doing it all the time. I have not spoken with them since they flushed and changed hydraulic fluid. If it was good news I figured they would have called.
That is a regeneration issue. I don't know if That model Case has a regeneration valve built into the arm spool or MCV but if it does you could always stiffen the spring if it has one to help. The issue is aggravated by the large bucket you have. The weight of the attachments on the arm causes the arm to move toward the ground faster than the oil can fill the barrel end of the arm cylinder. This causes the lag as oil has to fill the cylinder before it can continue through its range of motion. A regeneration valve will restrict the path to tank and redirect the oil from the rod side to the barrel side of the cylinder. Another method that can help is to restrict the line to the arm side of the cylinder. This will help control that runaway condition caused by the excess weight on the arm but can cause performance complaints due to increased cycle times.
Thanks Ben, would that then affect the blade due to the pressure issue?
That should only affect the arm circuit. The blade could be a pump regulation problem which could affect both circuits. Without a schematic it is hard to determine what your issues are. Does the blade just hesitate when you attempt to move it? If it is a pump regulation issue it should affect other functions as well.
The CX55B was built by Kobelco. If you have a Kobelco dealer in your area, they may also have a fix for that, that your CASE mechanic may not be aware of.