CAT 420D IT

I just purchased a 2004 cat 420D it backhoe. I just installed the multipurpose bucket and can’t figure out how to make the clam shell open and close. I have the yellow buttons on The loader controller. When I push them nothing happens. I switched the valve in the front loader, the lever that is for the locking pins, and still no function.

Serial bln05857

Is the attachment what you are trying to do..?
If the locking pins won't move when the switch is moved then possibly you have an electrical fault.
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With the valve on the loader in the vertical position, depending on which loader controller you have, either slide the thumb switch left and right, or use the roller. The yellow buttons are for electrical functions, not hydraulic functions like the MP bucket..