S300 - Aux hyd are strong in one direction but weak in the other

[txhayman]

I have a 2005 S300 and I have two problems with the aux hydraulics (the one on the front boom of the machine; I don't have rear aux hyd). First, as the headline reads, they are strong in one direction, but when you reverse it, they are very weak going the other direction. This is obvious when I'm using the brush shredder; one direction it cuts fine and the other it won't even turn the blades full speed. The second problem, and I think this is related to the first, is that the aux hydraulics have continuous flow in one direction and won't shut off as long as the machine is running. I believe it is in the same direction as the weak hydraulic flow. This happens regardless of whether the max/variable flow button is activated. When the fluid is cold, the continuous flow is slow, and when hot, the flow is faster (probably because it is coming from the weak flow direction). When I am using the grapple bucket, I must keep my thumb on the switch to hold it close, otherwise it will creep open. Same way with the tree shear, you shear a tree and the shears go back to the open position while the thumb switch is in the neutral position. I'm thinking the problem is mechanical rather than electrical because the max/variable button has no effect on the problem but I don't know for sure. Any help would be appreciated and please tell me where the aux control valve is located.