It's not worth all the crap to repair Jabsco heads, you were right to buy the whole thing. Takes about 20 minutes to undo the lag bolts and the clamps then install the new one. Make sure you replace the old clamps with new, have a spray cleaner, paper towel, two large plastic bags (one for old head) and a wet/dry shop vac. When you crack the lines open use the vac to suck up any water and crud. You can also vacuum out the old head as there's nothing to hurt when you do this. Keep the fixture seat if its any good as they charge $80 for a new one.