CAT 308 E2 CR Grade control locked

[M125X]

Hey guys,


Have a CAT 308 and the blade control is stuck in the “down” (aka FLOAT) position for auto grading. Any ideas? Happened once or twice a couple years ago but it “snapped out of it” and worked fine again until today. Now even after shutting off engine and restarting, messing around with other hydraulics etc it’s still engaged.

Thanks!

 

[uffex]

Good day
Check if you have mechanical spool control for the blade, be sure this is full stroking the spool before you begin checking out the blade cylinder.
Kind regards
Uffex

 

[M125X]

Hmm are you referring to the attachment spool control? Isn’t the blade just part of the main hydraulic system?

When the CAT is cold it pops right out fine. I started it the next morning and everything was okay, though still a little stiff to pull the level out of float mode, it did operate.

 

[uffex]

Good day
If you have a pressure gauge you can "T" into the two main lines see what you get when it is warm.
I can see if we have better instructions if you need.
Kind regards
Uffex

 

[Nige]

Good day
Check if you have mechanical spool control for the blade, be sure this is full stroking the spool before you begin checking out the blade cylinder.
Kind regards
Uffex

There is a pilot control valve for the blade is mounted directly under the lever in the OP's photo. Could there be a sticking cartridge in that valve.?

A Serial Number gets you the appropriate hydraulic schematic. The one I am looking at right now is for machines with S/N prefixes EC2 & MY2.