Is it the attachment or machine that's causing the problem?
The original problem was an inability to connect to the high flow "block" on the left side of the machine, which is clearly shown in Post 26 of this thread. Long story a bit shorter, the FFH10 couplings on the snowblower [attachment] side of the circuit were eventually loosened to relieve residual pressure buildup and, as also shown in Post 26, the snowblower was finally connected to the machine.
The subsequent discussion has revolved around options to permanently fix and/or relieve residual pressure on the attachment side of the circuit. Needless to say, the Stucchi USA casting shown in Post 36 of this thread is a great [and quick] way to relieve pressure in a closed circuit, but it's also a very expensive way to go about this...and, besides, it still doesn't help with residual pressure that builds up in the attachment side during temperature changes. Anyway, that's what we've been discussing here.