First let me say thanks to Mark at IM Bobcat in Utah I was able to purchase my glow plugs at a fair price. My question is that I was able to replace 3 of them without too much of a problem, but the 4th one is a real bear. What size and type of wrench do I need to use to take the injector line off. My open end is too wide to fit between the fittings. Do I need to remove more than one of the lines and is there any real danger that I will screw something up my taking the injector line off so I can get to the 4th glow plug. Also it starts like a dream with only the three replaced but I really want to change all 4.