I have a 1977 240d The brake pedal has gotten hard to push over the last three days. Now I cant press the pedal at all. I checked the brakes at the wheel and the all look fine. I checked the master cylinder but the fluid level looks fine. I checked the booster and there is very little vacuum on the line, Could this be the problem. Is there a certain amount of vacuum that needs to be on there. Also is there a way I can bypass the vacuum on the booster to see if this is the problem.Am I chasing my tail is there some other avenue I should look into. let me know
Thanks.
Roderic Houston Texas