Im having a braking problem with my 1988 Toyota Corolla All-trac. Pretty much I have no brakes… It started a couple of weeks ago when I was at a traffic light. While I sat there the brake peddle slowly started to go down and the car crept forward. I had to mash the peddle down to stopme car. I checked the brake fluid and it was full and I checked checked the brake pads and shoes and thoses were good too. I am not really mechanically inclined so I asked around and was told by various people that it could be either the master brake cylinder or the power brake booster. I checked the vacuum on the power brake booster and that seemed fine.
Is there any way for me to figure out which is which without replacing them?