Help! I am changing the water pump in my '79 gt. I have the old pump out with the fan assembly still attatched. How do I seperate them? It is the type of fan that is integrated with the fan clutch. I cant believe that any box end wrench will fit to remove the four bolts, and the large single bolt that attaches the fan to the flange won't budge

Yes, aren't those 10mm nuts fun? Can't tell you how many there must be out there with the corners rounded off.

First off, this job is indeed done with a hand wrench. The open end of a combination wrench will fit, but if you aren't careful or you've got a slightly inaccurate bargain bin wrench then rounded corners are ineveitable.

The box end of the wrench is the way to go, and preferebly a 6 point wrench if you can find one. For offset wrenches, turn the wrench backwards for this job. If your wrench is like mine, you may find you can't get the box end in between the threaded stud and the fan clutch to grab the nut. My solution was to simply grind the box end thinner until it fit. Best to buy a spare 10mm wrench just for this job then you can keep your main set in tact.