My cat 302.5 with 1556 hours on suddenly developed a problem with the stick. It extends very slowly with no power the lest resistance will stop it. It returns with normal force and speed. I have switched lines and changed the control pattern and neither had any effect on the stick. All other hydraulic systems function normally. I am thinking that a stick cylinder seal has failed. Is there anything else I should check out first. Thanks for any help
Update: I pulled the stick cylinder. There was a small scratch running the length of the tube. My Cat dealer honed the cylinder and installed new seals. That did not fix the slow stick problem. Since changing the control pattern had no effect I don't think the pilot valve is the problem. I have the service and repair manual for the machine, but it does a terrible job trouble shooting the hydraulic system. When put the bucket down into hard ground and try to move the machine the stick cylinder doesn't move so it is not leaking. Any help with identifying which valve might be the problem is appreciated.
You switched the lines going to the cylinder without doing a pattern change, and it acted the same? Sounds like a cylinder issue.
Without pressure gauges is there a way to check the stick cylinder to see if it is leaking?
Remove hoses from cylinder and cap off ports. Then try pushing on the stick to see if it drifts? Just a wild thought. Lol
My Cat 235 32K855 also has a slow stick and resealing it didn't help nor did the procedure to remove air from the pilot oil system at the back valve groups. My service manual is also pretty poor at helping an amateur troubleshoot it. I am guessing it may be a problem in the stick or stick crossover valve in the 5 stem valve group... but who knows? It also has no sensitivity to the swing and just goes full speed. Previous newbie owner took apart the left side pilot valve group that the associated lever control goes into but didn't find anything obviously amiss. Wondering if I should just try replacing that group though. Would really love to hire someone that knows this machine in the Rhode island area to come fix it up with me this week or later when I move it up to southeastern VT to build a permaculture ecovillage incubator. Any help would be appreciated. Also just purchased a Cat 235B that I am trying to put a 3306 sleeve metering cat engine in off a generator and hoping I found a pro who can convert the fuel pump and governor enough to make it work but that remains to be seen.