Do you mean under the valve body on the backhoe?
If so, I used regular open end wrenches (different sizes for different hose end fittings), but the wrench swing space is so small I had to keep turning the wrench over and over to take advantage of the wrench offset. If a hose in the middle is the busted one, you have to disconnect the outer ones first to work your way into it. I had to do this twice during the 17 years I owned the 4500...each time one of the inner hoses blew, but both times I replaced all of the hoses because it's such a nightmare to get at them. I sold the tractor 4 years ago...I can't remember what size wrenches I used.