Maybe Im doing something wrong or a bad grease gun. On my Hustler X-one and Commercial Toro 21 walkbehind the gun goes on easy but is a pain to get off. I have to use pliars and bust my knukles trying to get it off. Also doesnt want to squeeze grease into the zerk. Both piece of equipment was bought just this last summer. hustler has 120 hrs, toro maybe 80. Whats the best grease gun? Thought about getting one of those mini ones. The old gun is in the trash, Im fed up with it.