hydraulic power loss

meangreene · Apr 13, 2006

I have a 4710 hst w/ 460 loader. After about 6 months the front and rear hydraulics "slowed down". Let's put this in perspective. It's a golf course machine, many operators ( many stories ending in I didn't do it). A hose broke on the backhoe, it was fixed and then removed to run a pto powered blower. There was a 3 month period before the hydraulics were really used again( lifting loads etc.) I noticed that performance was horrible, nothing at idle, barely a half bucket at 2500rpm! Yes! I changed both suction filters and drained fluid and cleaned the suction screen. No difference at all. I did notice a few small metallic shavings in the screen. Could this just be a bad relief valve? If so can anyone tell me exactly where they are on this machine and are there more than one? Can I really have a bad pump on a year old machine? I don't want to lose this to a dealer for the summer, we need this! i need to fix this quickly but we still use it for the pto almost daily. THANKS for any help.

plowrup · Apr 14, 2006

Someone need to plug into the SCV's and do a flow test (a test that checks not only pressure, but GPM as well)-from that information a more thorough evaluation can be made-

kennyd · Apr 14, 2006

( A hose broke on the backhoe, it was fixed and then removed to run a pto powered blower. )

Which hose broke?
Was it the PowerBeyond hose that feeds the Backhoe? Possible a connection was not made properly during this repair.
Was teflon tape used on the connections, if so-it is possible that to much was used and some got into the system causing a blockage.

JerryG · Apr 14, 2006

I know that the guys here are going to get tired of me saying this. Check the hydraulic quick connectors. They are the number 1 reason for lose of power for the motor as well as the hydraulics. They will look like they are connected correctly and may actually work to some extent. Even if everything still works some, the QCs can still be partially disconnected. Like I said they might look connected, but not be. Check all of them, where they connect to a loader, three point, remote valves etc.

meangreene · Apr 17, 2006

Found the problem! Took the implement hydraulic pump off to inspect and found a spun bushing allowing one end of one shaft to move 0.075" over into the housing, chewed the housing, the gears, plates etc. Whole pump is junk! ONE MONTH OUT OF WARRENTY!! Probably been bad from the start, hence the gradual power loss. Thanks for the ideas though!

JerryG · Apr 17, 2006

Whole pump is junk! ONE MONTH OUT OF WARRENTY!! 
Ouch! That hurts, seems to be the way things usually work for me too.

rockyridgefarm · Apr 17, 2006

One month out of warranty is where a good dealer realationship really can pay off. Are they telling you that it can't be covered, or is that your assumption? It certainly can't help asking...