are the 4agf4 ag4f4 coupler set bi directional?
ISO 5675 Coupler Sets
I purchased a set of these and they appear to be closing off during normal operation. I have a smaller JD tractor with a front bucket. I installed these to all to swap from bucket "curl up/down" to a spreader with a hydraulic live bottom. I mounted the male ends on the valve body and the female ends on the hydraulic hoses. I since have removed the QCs and the hydraulics function as designed.