Where could air be getting into brake system? Hardly, if any, rear braking.?
its really deap, and different. but its okay
no, not at all dont quit your day job, or even do this as a hobby ;)
I would make sure the rears are adjusted properly. If the star adjusters are not set right after a brake job the shoes will not touch the drums. Also ask the shop if they bench bled the master cylinder properly before they installed it. If the all of the air is not purged out of the master before the lines are attached, you will not be able to get all of the air out. Good Luck
Theres a couple things I can see immediately off the start. I own a 2007 Cobalt LS and it has rear drums, and I agree I haven't seen them do much of anything since I got the car, but as the commercial says, the front does about 70% of the work. If your front brakes work fine, chances are its something in the rear lines, air is a big thing especially with older systems, bleeding them the right way and the right order is critical to getting the air out. Another thing could be the actual drum cover, where the pads rub against. If the drum cover is under spec minimums, the pads won't even touch the walls. You need a shop or a micromoter to tell you whether this is true or not though. I wouldn't be surprised though if they were too thin, it'd explain the lack of control in them since the beginning and consider the age of the car, it is a likely possibility.
Another 40 year old vehicle with the same old problem. Either the workmanship is defective and air hasn't been removed from the lines correctly or your brakes are boiling the fluid thus causing air pockets to form in the line/s. Since air is compressible, this is why the rear brakes feel spongy (the vague feeling). Save some cash and invest in a disc braked rear end. problem solved. Can you post a pic of the whole car?
