5.0 Water Pumps
The last 'in car' 5.0 water pump I replaced was on my 1987 Grand Marquis. The symptoms of failure were a subtle anti-freeze odor in the engine bay, which surprisingly enough had been present since the vehicle was new, although I could never detect any leaks. When the pump finally let go, the coolant begins to leak out of the 'weep hole' in the top of the casting where the shaft runs out. Luckily it wasn't a catastrophic failure as I was able to drive the vehicle (with somewhat frequent pit stops) around 500 miles back to my home. The local dealers/repair shops wanted an obscene amount of $$$ to replace what amounted to a $40 part (brand new from NAPA). It took me about six hours to replace mine, and that included a bit of 'running around' part searching.
Disconnect the battery.
Drain the coolant (Duh!).
Remove the radiator, shroud, fan. Label the bolts or thread them back into place.
Make a diagram (or take a pic) of how the belt(s) are routed.
Start at the front of the motor and work toward the block.
Move the accessories over to the side and secure using rope/twine/bungees/etc.
Be careful removing the water pump bolts! For the most part the actual water pump bolts thread into or through aluminum die-cast housings. Breaking one of these off and you're in for a real fun time. These bolts are like gold at the dealerships. I think they quoted me around $8 per and this was back in the early 90's. And you're not gonna find them at your local Home Depot. They are threaded 5/16 on the motor side, and 3/8 on the accessory side. And they have varying lengths. If you're not running any accessories, then it's not a problem. But you are. Inspect (and clean!) those bolts once you get them out. I can't remember for sure, but I know at least one of them runs through open coolant before getting into the timing cover. These bolts may have rusted to the point that you shouldn't reuse them. Assuming you haven't snapped it off already. I wasn't so lucky, I ended up using a small pipe wrench (ViseGrips didn't work) to remove it. Then it's definitely a trip to the dealer (or perhaps junk yard, although at this point I sucked it up and got a new bolt).
Remove the old gasket material carefully! Don't get in there and start gouging with a screwdriver. Take your time, cause if you dig into the surface of the timing cover, you'll have a hell of a time getting the new gasket to seal correctly.
I used Hylomar on the new gasket when it came time to reassemble. Also coat the shanks of the bolts that pass through the coolant in Hylomar. This will help delay any future rusting. Oh, and use a bit of anti-sieze on the threads.
As far as water pumps go, buy a new one. It's not much more than a rebuild and the warranty is better. Although it only covers the actual part, the real cost of this repair is the labor involved...As you will find out.
You do own a torque wrench, right? Use it. Torque spec is 12-18 lbs.
Reassemble/Refill/Reconnect. Elapse time: I'd budget around 3-6 hours, depending on how the bolts come out and how they look.