I'm sorry I forgot to warn you about that. When I replaced mine the first time I nearly stripped the allen head of the large banjo bolt on one side. Before proceeding I ordered 2 banjo bolts---one to replace the damaged bolt and the other to be held in reserve for the other side. IIRC obstructions prevent a aligning the allen socket correctly and may require removal or relocation of the instruction. Anyway, one secret to loosening the bolt is to clean the bolt head, insert a high quality 1/2 inch drive 10mm allen socket into the bolt with a suitable extension and strike the extension head firmly several times with an appropriate 2 lb. hand sledge hammer (observing all safety rules concerning eye protection, etc.). Then, using a breaker bar apply high torque to the fitting as instantaneously as possible. A gradual increase in torque will more likely than not result in a damaged bolt head. I have never tried to loosen these banjo bolts with an air impact wrench but I suspect that will also work. Also, don't forget to replace the 4 copper seal rings for these bolts or you will have leaks. Mark