743 With hyd. problem

[chopper03]

My 743 has a problem anytime that the aux hydraulics are dead headed against relief pressure or the tilt is dead headed all the way back or dump the boom will raise on its on. Anybody got any ideals ?

 

[OldMachinist]

Sounds like a problem in the control valve. Weak centering spring or bad seal.

 

[lfutrell]

Sounds like a problem in the control valve. Weak centering spring or bad seal.

I had the same problem with a 743 I had a few years ago, When I used a log splitter on it, when I deadheaded the log splitter it would raise the **** about 1/4 inch, after a few times of this you would have to get in the machine and lower the boom, I resealed the control valve but I did not change the springs, I just learned to live with it and it was still that way when I sold it.