Brake Master Cylinder: Bringing a Car Out of Long-Term Storage

Brake fluid by its nature is hygroscopic, meaning it absorbs moisture out of the air. This moisture in the fluid causes corrosion in the various brake lines and components, also the harsh fluid can eventually compromise the rubber seals in master cylinders, wheel cylinders and brake calipers.

Once the brake fluid begins to leak from the system air and moisture will find their way in, further compromising the system. It’s a tough scenario for many who expect their cars to work as perfectly as they did when they stored them, but when bringing almost any car out of long-term storage these types of problems can be expected.

Join Mark Simpson as he works to bring our project car out of a 30-year slumber and address many of the items that have failed, including rebuilding the master cylinder. Let’s face it, for some classic cars the availability of replacement master cylinders is simply not there, yet for most there are rebuild kits available.

Rebuilding a master cylinder is a simple, three-part process that includes disassembly, inspection and assembly with new seals and components. The two main reasons a master cylinder fails are corrosion in the main cylinder and the seals in the piston have failed.

Simpson carefully inspects the cylinder bore on the disassembled master cylinder, as any sign of pitting would necessitate having the master cylinder bored and sleeved to function correctly. With a little time and effort rebuilding a Master Cylinder is a task most enthusiasts can take-on to ensure miles of trouble free driving.