Hi, I have a 2008 Caterpillar 315DL that has aux hydraulics that we run a demoliton grapple on. It has 4 lines, two on each side of the stick. This grapple one function opens it and one closes and one turns left the other turns right. I have attached pictures of where it comes out on the boom, the grapple turns left and right fine but does not open, only closes. The machine has to be revved up high for it to barely open. I am thinking it may be one of these solenoid valves? The only thing that throws me off is when you disconnect the wiring from both valves it still functions the same?
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