New Thomas Air Compressors, Rebuild Kits and repair parts. Thomas Air Compressors are made in the U.S.A. All rebuild kits include O-Ring Gaskets, Reed Valves and Piston/Cylinder Assembly. We also have select Air Filters and new units available. Thomas Oil-Free Air Compressors are some of the best oil-free units made, it's worth it to rebuild your compressor and keep spare parts on hand! If compression is low, usually this is due to a damaged compression (piston) ring, worn cylinder or broken reed valves in the pump. A Rebuild Kit should repair any problem with loss of compression, or slow compression. Make sure to keep your inlet air filter clean, as it keep debris out of the pump.