If it has been a few years since you serviced your brakes, chances are good you have a leaky wheel cylinder somewhere. These get pitted over time, the seals get chewed-up by the pitting and then they leak. So check your wheel cylinders every time you remove your tires-you can get a quick read of their condition by looking through the brake adjusting hole. If you see any wetness or corrosion evident, remove the drum immediately and inspect. Once the cylinders leak, your shoes will soon get wet and the brakes will no longer work.
We sell a premium cylinder made in England which we have found to last longer than the inexpensive Asian made reproductions one commonly finds online. We recommend that you buy the best cylinders possible, so you get the greatest longevity. No one wants to re do this job any sooner than needed.
Your car has 2 front wheel Cylinders per side and 1 rear per side. If you discovered a leaky wheel cylinder you should also replace the brake shoes and clean the drum with brake clean. Check your hoses too!