it should take two gallons. Best way i know of without using the special collant sucker is to open the cap, open the bleader screw on teh small metal pipe and squeese the hosees and bunch. then start it up and wait till the collant comes out of the bleader screw and a good pace and then put the screw back in but keep squeesing the hoses and it rocking the car a little. jacking up the one side can help a lil as well