How do you adjust the rear brakes on a 1990 Nissan pick up with new brakes and they have been bled and pedal goes down almost to the floor?
If your brakes are new and the system has been bled, your next step is to see if you have a leak in any of your brake lines and also check your brake master cylinder to see if it's working or not.
They do. Every time you back up and step on the brake, it activates the self adjuster. It has it's limitations. If you don't know how to manually adjust your drum brakes, have your mechanic do it for you. If you feel your brake pedal is mushy or you have to push it almost to the floor, it may mean your rear drums need adjusting.