Hello all first post here I have a 315cl and just installed a hydraulic thumb. From the factory it was plumbed for a hammer and The machine had previously been equipped with 2 way auxiliaries at least 10 years ago which the previous owner never used So here is the dilemma the aux are proportional and at idle or slightly above operate normally, when run near full throttle the thumb is very slow, you can actually activate the thumb and it move normally then rev the engine and it will abruptly slow down CAT0315CLCJC03124 I am including pictures of the auxiliary pilot valves And plumbing
New revelation..... if I use another function, like the stick in or out it moves at a proper speed
If it was plumbed for a hammer then one side of the circuit will be open to tank.Check what end goes to tank and connect it to the aux side of the valve.The reason the thumb speeds up when you use another function is that you are telling the pump to stroke .