An equipment service apparatus, which is suited for use in servicing ground support equipment (GSE) or aircraft ground equipment (AGE), includes a plurality of features for use in servicing and maintaining the GSE/AGE where the GSE/AGE is in use servicing an aircraft so that the GSE/AGE is not itself required to be transported to a remote location for servicing and/or maintenance. The apparatus may be constructed as a towable cart. The apparatus may include a fuel tank, a pump system configured to add fuel to or remove fuel from the fuel tank, and a fuel valve assembly operable to control fuel flow into and out of the fuel tank. The apparatus may also include a container storage portion configured to retain a plurality of removable fluid storage containers, at least one power source, and a power control system operable to control power from the at least one power source to operate at least some features of the equipment service apparatus.