BrandonKuemper
New Member
Hi all, I have a grey market 2012 yanmar vio55-5b. It was running awesome until I lent it to a contractor for work. They ended up backing out my bushing and bending my main ram and boom cylinder. The machine shop repaired it and a mechanic put it back together without flushing the hydraulics as they said there was no need....
I bring it home and all of a sudden my left track under solo operation locks up on me. I lift the track off the ground and it runs fine in forward and reverse - I inspected for rocks or anything blocking my tracks. Nothing! I put the track back down and try it under load and it locks. If I use both my left and right tracks under load there is no issue in forward or reverse - just when my left track is under solo operation.
I dopped all my hydraulic oil, clean the tank and replace my return and vacuum filter - I notice some crud and what looks like warn hydraulic hose pieces in the bottom of the tank. There was minor fine metal on the magnetic plug - but nothing too major.
I put new oil in and all of a sudden I loose power in not only my left track but now my arm and boom swing function.
My boom up/down is fine. my blade is fine, and my right track is fine.
I pull the relief valves of P1 and P2, clean them and reverse them to see if the function changes -- Nothing ! its exactly the same.
I put a pressure gauge to P2, and dead-end my boom - reading is 3600psi.
I deadened my arm and bucket and it slowly builds to over 2000psi then immediately drops to 350psi.
I changed my gear oil in the left track and seen nothing crazy - little crud.
from my manual, it seems that all my functions that are weak come from the P2 pump.
Any help diagnosing this would be awesome.
I bring it home and all of a sudden my left track under solo operation locks up on me. I lift the track off the ground and it runs fine in forward and reverse - I inspected for rocks or anything blocking my tracks. Nothing! I put the track back down and try it under load and it locks. If I use both my left and right tracks under load there is no issue in forward or reverse - just when my left track is under solo operation.
I dopped all my hydraulic oil, clean the tank and replace my return and vacuum filter - I notice some crud and what looks like warn hydraulic hose pieces in the bottom of the tank. There was minor fine metal on the magnetic plug - but nothing too major.
I put new oil in and all of a sudden I loose power in not only my left track but now my arm and boom swing function.
My boom up/down is fine. my blade is fine, and my right track is fine.
I pull the relief valves of P1 and P2, clean them and reverse them to see if the function changes -- Nothing ! its exactly the same.
I put a pressure gauge to P2, and dead-end my boom - reading is 3600psi.
I deadened my arm and bucket and it slowly builds to over 2000psi then immediately drops to 350psi.
I changed my gear oil in the left track and seen nothing crazy - little crud.
from my manual, it seems that all my functions that are weak come from the P2 pump.
Any help diagnosing this would be awesome.