An upgradeable A/C maintenance system and methodology is provided including one or more modular manifolds for mounting and fluidly connecting several components. Embodiments include first and second manifolds, each for removably mounting a plurality of components, and each comprising an internal passage for fluidly connecting at least two of the plurality of components to each other, and a port for fluidly connecting the internal passage to an external surface of the first manifold. The first and second manifolds are removably attachable to each other such that their respective ports fluidly communicate with each other. The first manifold provides a first functionality for the system when the second manifold is not attached to the first manifold, and the second manifold provides a second functionality different from the first functionality when the second manifold is attached to the first manifold.