Well i purchased a yanmar vio45-5 with 240 hr on it from a rental yard and the hydraulic seem to be a bit slow, so would they have turn down the pressure on the pump or reset pressure valves? Because when i'm digging in hard dirt and i pull the dipper arm and roll the bucket and then pull on the lever to lift the boom it wont lift until i back off on the arm and bucket. but it only doe it in hard digging and when cold I have to pull the boom lever nearly all the way back and then it lifts.:Banghead:Banghead
I know at the rental company yard I work at we do not turn the pressures down
I've never known of any rental yard that could fix a dead battery let alone adjust pressures and flows of an excavator hydraulic system. More likely the machine is just beat hard enough and never re-adjusted back to spec.
john c that is not a nice statement that a rental yards can not ajust pressures right or fix a dead battery. We do a lot of heavy repair work at my yard.I work as road tech and some have set pressure on the road on all types of equipment.
tool king could in be a sticking spool valve maybe or there's not enough flow left for the boom cylinder to lift? I here in a australia they turn them down so people can't do any damage
I know a contractor that had to have there Yanmar pump woked on around 600~700 hours for a similar issue, I think they own a vio27 so the pump sint the same but it could be possible you have low flow . If I recall the fix wasnt really expensive for a pump issue. Get it to a shop that can check flow and pressure , you dont want any broken parts that may be in the pump tearing things up worse.
I'v worked for a rental yard for 20 years as a road service tech, we have a large fleet of excavaters, loaders rough terrian forklifts ect. We never turn down pressures, this would cause more harm than good. Find out what the Pressures specs are for your machine and the rpm of your travel sprockets are. Travel sprocket rpm is a good way to see if your pumps are putting out the right gpm. I dont have these specs but I bet somebody does.
We never turn down pressures on our rental fleet, in fact we "tune" up some of our machines. We sell alot of equipment from the rental fleet because the customer likes it.
Make sure your lever for the back fill blade is not sticking in the lift mode or some other function is on and going over relief like for example PTO hydraulics.