I have a bobcat 341 and can't seem to figure out why the thumb hydraulics won't stay up. I have eliminated the ram being the issue and replaced the pedal vavle. Any ideas?
Good day Most probably it will be down to a leaking spool - housing or shock valve attached is a comprehensive diagnostic instruction how to find what the issue is. While this covers all backhoe cylinders the same technique applies to the thumb cylinder. If you would like information specific to the Bobcat drop me a line. Kind regards Uffex
Good day Looked not the Bobcat issue please see attached if the result is that of the spool we suggest you approach a supplier for check valves similar to the link https://www.prcindustrialonline.com/rd-1400-lock-valve/ this will resolve your issue. We are not so sure which of the option spools your thumb is hooked into but a guess is that powered by the load sensing pump as the gear wheel pump appears to have no provision for shock valves. If you need more help please drop us a line. Kind regards Uffex
Good day Attached the information we have used to determine the possible cause of the thumb cylinder creep, we have assumed that the thumb main valve is that powered by the LS side of the hydraulic system, however this detail has little relation to that of the problem other than the lines have port relief valves. Maybe there are other guys on the forum that can help some more should ou need . Kind regards Uffex
I have the same issue on a e45 bobcat mini, (which had a factory bobcat thumb on it at 1 point) since I installed an aftermarket hydraulic thumb, machine make a real whining noise after about 5 mins of use w the thumb,) I also run a hammer on it with no issues, there has to be a simple fix? filters were just serviced and checked for metal.