Cleaning W/Wash and Coolant Tanks

FYI: A good way to clean the inside of scuzzy W/Washer Tanks and Coolant Tanks is to use Easy Off Foaming oven cleaner. Spray it on the inside, let it do it's magic and then flush it out with hot water. Be sure to use gloves and eye protection. 

You can use it on the outside as well. Makes an old tank look almost like new.