I have a 773 that has had lift arm problems for some time but I have just been dealing with it. It would not hold a load up without keeping constant pressure on the lift pedal. The more weight you had the more lift pedal you had to apply. A real pain for sure. Now, this problem still exists even worse than before since now you have to apply full throttle to keep it up. To make things worse the the tilt pedal is locked completely so that I can't tilt the bucket either way. Lift arms are still working barely but no tilt at all. Anybody got any moral support cause I know this isn't going to be good news. What's wrong with it and how do I fix it? Thanks in advance.
773 Hyd Problem
- Thread starter rhtrigger
- Start date
It depends on your model, some newer machines have solenoids on the spools to lock the pedal out. The older style had blocks that got mechanically moved when you lower the seat bar. It may simply be locking you out because the seat bar or seat sensor are bad.
The lift arms falling sounds like bad piston seals, but if you need to really rev the machine it sounds worse. Do the arms lift and fall at a pretty good speed? same with curling the bucket? (tilt) when it was working that is. I'm wondering if you may have a bad gear pump or your aux hydraulics are stuck on some how. Causing all your pressure to go over the relief. This could explain needing full throttle to get the arms to stay up but they really shouldn't fall when you aren't pushing on the pedal.
The lift arms falling sounds like bad piston seals, but if you need to really rev the machine it sounds worse. Do the arms lift and fall at a pretty good speed? same with curling the bucket? (tilt) when it was working that is. I'm wondering if you may have a bad gear pump or your aux hydraulics are stuck on some how. Causing all your pressure to go over the relief. This could explain needing full throttle to get the arms to stay up but they really shouldn't fall when you aren't pushing on the pedal.
skidsteer.ca
Well-known member
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- Jan 20, 2006
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If the arm creep down after lifting, Here is some reading
http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=20379
Common problems are cylinder packing aka piston seals or main control valve leaking.
If they have trouble going up it could be a bad pump failing to make pressure or a bad leak in the lift cylinders piston seal. To test your pump it is best to have a flow tester, but a 5000 psi guage can be hooked to the front aux hyd couplers to give you a idea. If the pump won't make the 2500 to 3000 psi relief pressure setting (the actual setting depends on what year machine) then you may have a bad pump, or a relief valve that opens to soon.
How many hours on the machine or how old is it?
Ken
