Brake booster replacement

I would try some salvage yards first for the booster, thats where I found mine. I replaced the master cylinder rather than trying to clean the old one I got with the booster. I paid $25 for a reman unit at the local auto parts store. The hardest part of the job was taking that bolt out that connects the pedal to the push rod-not much room to work under there. The four nuts on the firewall were simple.