Finally got it hooked up. Checked the couplers, they were okay. The couplers would slide in but not far enough to snap in. Loosened the couplers from the hoses on the grapple and it hooked up fine. I guess there was pressure on the grapple couplers when I took it off. Should have known to check that, thanks for the suggestion, have learned alot but have much more to learn.Is it possible your quick coupler is rusted?
What happens if you push on the coupler, does it slide in a little? some have a de-compression feature that when you push on the coupler in, it decompresses the fitting.
I have even found that when I move my grapple out of the shop and leave it in the sun, the heat will build up enough pressure in the lines that the QD's are difficult to hook up. Annoying....Finally got it hooked up. Checked the couplers, they were okay. The couplers would slide in but not far enough to snap in. Loosened the couplers from the hoses on the grapple and it hooked up fine. I guess there was pressure on the grapple couplers when I took it off. Should have known to check that, thanks for the suggestion, have learned alot but have much more to learn.