[Sam Mac]

If your brake pedal is sticking partway down that may be your problem as far as going forward or reverse. My other bet would be worn linkage and trunnion. See what happens if you pull up on the brake pedal. Just patched up my 149 a couple months ago, it had the same problem with reverse. Trunnion springs were toast and the pivot points were sloppy. Got some machine washers from McMaster to shim things up and all good now. PITA to get them in place with the tranny in the tractor but I was able to do it with a set of right angle snap ring pliers. If you need some of the washers let me know, I had to buy about 10 of each size, only needed 1 of each.