This is a 980 G 2KR03066 front end loader new in 1999 and now has a bit over 26,000 hours. Well just as I was leaving work operator comes in and says the bucket is drifting, says if he is holding loaded bucket in air while waiting for next truck to back in the tilt cylinders will start drifting. Like I said I was walking out he door at the end of the day so did not have chance to see how fast this was happening and won't be back on the job till Monday morning. Both tilt cylinders were resealed a couple months ago and he did not mention any external leaks. This machine has the control valve up front with the solenoid controls. I love how every time you remove the cover over the valve it is buried under a foot of wet dirt and stone, not the best location for that wiring and those solenoids! Just wondering if someone has a good place to look, trying not to think too much about it over the weekend But I'll at least take a look on SIS and see what I find!
Well a quick look comes up with this: 10.If there is too much drift, check the check valves and check the makeup valves. Not sure I really want to try to get those plugs out that have been in that crap for 15 years! Here's what I found one time I had a problem with one of the solenoids: Good news is I have to replace the front wiper motor in the other 980 G first, another fun job! Beats working on the JCB that spends more time in shop than out doing clean up in quarry! and it never the same problem, unless you consider the guy sitting in the seat with hands on joysticks!
Does the 980G tilt circuit have a line relief valve..?
That there is: #10 and #11 in image. I read the section on adjusting them but still need to see how to test them for leaking.
As a first step try pulling it apart and see if anything is damaged. Then try testing it.