1999 Bobcat 331

[Seven Gables]

Follow your auxiliary lines back from the boom , they should lead you to the DCV (directional control valve) for your auxiliary circuit. I’m not at all familiar with your 331 but mine and any I’ve seen are sandwiched right in the main control valve stack.

 

[kclark2227]

Have you located the spool valve for your auxiliary lines? You’re port relief valves if the machine is equipped will be on this control valve. There should be two , one for each port. Look for a Allen head set screw with a jamb nut , that’s your port relief. If it has them the one that goes to the base end of your thumb cylinder will need to be adjusted with a pressure gauge. Set the set screw to relief at less than your thumb cylinder pressure rating. Post a pic of the auxiliary valve if possible

See if this is correct.

 

[Seven Gables]

View attachment 746169

See if this is correct.

 

[Seven Gables]

You’re auxiliary rod looks like it goes to the valve to left of that Allen head screw and no that Allen head screw is not a adjustable port relief, it appears to be just a port plug. Do you have 2 floor pedals? One for boom swing and one for your auxiliary? One way or the other you’ve got to find the correct DCV for your auxiliary lines and see if it has port reliefs like in the picture of mine with Allen wrench inserted.

 

[kclark2227]

You’re auxiliary rod looks like it goes to the valve to left of that Allen head screw and no that Allen head screw is not a adjustable port relief, it appears to be just a port plug. Do you have 2 floor pedals? One for boom swing and one for your auxiliary? One way or the other you’ve got to find the correct DCV for your auxiliary lines and see if it has port reliefs like in the picture of mine with Allen wrench inserted.

I have 2 floor pedals. The right one swings the boom left and right and the left should be Aux.

 

[Seven Gables]

So does the valve that you’re auxiliary pedal linkage goes to have the adjustable port reliefs like in my photo? If it does have them you’re in luck and the one that reliefs for the port to your base end of thumb cylinder will simply have to be adjusted to less than your cylinder pressure rating. From your picture you’re white arrow is in the way of what may be a port relief on the valve that the rod appears to be going too.

 

[kclark2227]

So does the valve that you’re auxiliary pedal linkage goes to have the adjustable port reliefs like in my photo? If it does have them you’re in luck and the one that reliefs for the port to your base end of thumb cylinder will simply have to be adjusted to less than your cylinder pressure rating. From your picture you’re white arrow is in the way of what may be a port relief on the valve that the rod appears to be going too.

I may need to get another photo or 2.