The solenoid test facility at Fermilab was built using a large vacuum vessel for testing of conduction-cooled superconducting solenoid magnets, and was first used to determine the performance of the MICE coupling coil. The facility was modified recently to enable the testing of solenoid magnets for the muon-to-electron (Mu2e) experiment, which operates at much higher current than the coupling coil. One pair of low-current conduction-cooled copper and NbTi leads was replaced with two pairs of 10-kA high-temperature superconducting leads cooled by heat exchange with liquid nitrogen and liquid helium. The new design, with additional control and monitoring capability, also provides helium cooling of the superconducting magnet leads by conduction. A high current power supply with energy extraction was added, and several improvements to the quench protection and characterization system were made. Here, we present details of these changes and report on performance results from a test of the Mu2e prototype transport solenoid (TS) module. Progress on additional improvements in preparation for production TS module testing will be presented.