How do you replace the water pump on a 1990 Geo Metro?
First while the belt is tight, remove the bolts from the water
pump pulley,drain the radiator then take the drivebelts off. Remove
the timing cover and timing belt then remove the water pump bolts
and be sure to remember which bolt goes where because they're
different lengths. Pull the old pump off, clean everything up and
put the new one on. Put it all back together. As long as you've got
the timing belt off, inspect it carefully and replace it if it
looks the least bit worn. That way you won't have to worry about it
for another 60,000 miles.