The inside rear face of the dyno housing is stepped outward & fits precisely (.0001 clearance) inside the stepped inward front half. Notice the pockets; water inlet; barrel type water valve & the spring loaded graphite reinforced PTFE center shaft seal. A similar seal is used in the front housing half. No "o" ring is used to seal the dyno housing, only a very high finish on matting surfaces. There is no water leakage when operating the dyno!
