How do you replace the water pump on a 1985 Cadillac Fleetwood 4.1L front wheel drive?

Disconnect battery. Drain rad, there's a plug on the back side towards the bottom of your rad that screws out. You have to take your serpentine belt off (1\2" rachet into tensioner), and remove your alternator. Find a way to jam the pully on your water pump ( its just below the alternator ) to take it off,a pair of vicegrips work well. There will be about a dozen 10 MM bolts going around the water pump. Take those out along with your idler pully ( the free spinning wheel towards the firewall)if you need to ( only if you have the 3 peice bracket, mine did but i replaced it with the 1 peice from an 86 or 87). if you pull on the water pump it should come off of the engine. Make sure that you remove all of the old seal before installing new pump and seal. You may want to use a little sillicone to hold the new seal to the pump to stop it from moving around.