Help! NH L455 Won't move.

[GLWelder]

Hello Guys, I have an older (1986-7) NH L455. I have just in the last month replaced a bunch of o-rings on the control valve and every fitting I could get a wrench on to fix a hydraulic leak. The machine was running sweet w/o any leaks for about a month when it stopped this morning. I was starting to move some rottomill and slammed pretty hard into the pile when the hydrostatic charge warning came on and nothing moved. The fluid level is ok and the diesel runs fine but nothing moves and the pumps are whining like crazy. I didn't run it long, I know its not good for the pumps. Thanks for any feedback, George

 

[92LX555]

Boom does not move as well? Or is it just the wheels? Shut it down.....does the charge light come back on?

 

[GLWelder]

Boom does not move as well? Or is it just the wheels? Shut it down.....does the charge light come back on?

Nothing will move. I turned it off and on several times, hydrastatic alarm comes on right away. I'm hoping its a stuck "over pressure" valve somewhere.

 

[Earthwerks Unlimited]

Nothing will move. I turned it off and on several times, hydrastatic alarm comes on right away. I'm hoping its a stuck "over pressure" valve somewhere.

The charge pump is only for the hydro pumps.
A gear pump is used for the loader/bucket and aux. It doesn't need a charge pump since it sucks oil on it's own.
Sounds like you blew a line or fitting somewhere and oil is going there instead of where it needs to be. My '05 LS185.b blew a fitting off the drive motor and the same thing happened to me--no up/down and drive wheels. This time it puked a about a few gallons--when a smmall o-ring split when it was only 12 hours old I lost all the fluid over a few days. Thought about getting a big diaper for it since it was leaking fluid everywhere. But that Depends (pun intended LOL)
You may also have a clogged filter(s).
And you checked the obvious, right? Fluid level.
Yours may have a strainer in addition to the fliter(s) that needs to be cleaned or replaced.