The Fill-Tech automatic yoke clamping system drastically reduces the time and labor spent tightening yokes in preparation to fill cylinders. The automatic rack seals the yokes to the post valve by hydraulic force, simply push the lever down to engage all cylinders and flip to the up position to release the filled cylinders. The system is powered by a booster pump that uses oxygen safe, hydraulic fluid. The pump only requires 120 psi shop air to function.