Grey market machine (Mitsubishi) owned it for 16 years and it has never done this. It dropped off cold here and I used it to clear a foot of snow out of the driveway and that is when I found the tilt cylinder for the 6 way blade had a issue. it will extend but does not want to retract. it will retract very slowly while activating the bypass valve so it is under pressure. I will add this is the only cylinder left on the machine that I have not repacked (yet). The rest got repacked due to leaking but they all worked fine and I probably could have got by without a total repack but what the point it's the same amount of work. Any ideas? I have used this dozer in -25* weather before and never had a issue.
Is the tilt function the only hydraulic function not working correctly? If so the issue should be isolated to that one circuit of the blade control, I'm not an hydraulics guy but there should be someone along soon that can help you. I would start by checking that the control valve is working that section freely...and the distances it should be. It may be that the pins at the ends of the cylinder are binding also but if the piston does work both ways albeit slowly that likely is not your issue.
{Is the tilt function the only hydraulic function not working correctly?} Yes, everything else works as it should. I am starting to think maybe a hose issue, I know brake caliper hoses can fail in this fashion...
Yes you are right, may have a collapsed hose lining and maybe to the point its started to come apart and plug small orifices and such. Or at the very least blocking the flow at the point of collapse.
If it will extend but not retract, you could switch the lines around on the cylinder and see if the problem follows. This will separate the problem from valving/lines to cylinder. In my experience, nine times out of ten the problem is usually within the cylinder
I don't know when I will get around to this, the weather is a real **** show here and will be for at least the next week. I will probably take both lines loose and put them in a clean bucket and see what happens. If it is in the cylinder that might be a good thing, I can take it off and work inside in the warm. whatever is going on with it, it happened sitting. The last time I used it was that freak hurricane we got the aftermath of back in late Sept to push a few trees that fell and everything was working fine then.