Since everything was hot, and I was riding herd on the kids, I tried without removing the belts. There was a slight amount of slack in them and figured the pully would slip with a little pressure. No movement at the pully, nor belts.
I agree it is not advisable to try to turn the engine by accessory drives, however, in this case due to the slack, I felt the pully would slip before the crank moved.
Not five minutes ago, after the car had cooled for about four hours, I started the engine and the pump was turning. Then, again tried to turn the pully with a wrench. There was enough slack and I could move the pully about 1/4 inch with out much effort, due to the pully slipping under the belt.
After taking a second look, here's what I think is happening: For whatever reason, the pump impeller dragging, worn bearing or something else, the pump overheated. The excess heat caused internal parts swelling which seized the pump. The metal cooled, the internal parts returned to proper dimensions and the pump freed up.
When I first popped the hood, and began checking the pump, the pump was *very* hot. Today was a hot day here, but not that hot. The pump was too hot to touch after the short 10 mile drive home, more than likely internal heat build-up from the pump failing. I could test the thoery by driving to work it tomorrow, but then I'd stand the chance of losing the belts and toasting a great running 117 engine.
I guess after 27 years, I can expect the pump to fail. By the condition of the surrounding area and mounting bracket, it appears this is the original pump.
73 280 SEL 4.5
[This message has been edited by MikeTangas (edited 04-27-2000).]