pH TEK and probe keeps popping back out of the holder

If your probe keeps popping out of the holder check to ensure that probe holder top is fully tightened down. Tighten the probe holder so it is snug. DO NOT OVER TIGHTEN if you over tighten the probe holder it can cause damage to the holder and leak. Also Check to ensure the spacers and o’rings are ordered properly. The correct order should be starting from the bottom spacer/o’ring/spacer/o’ring/spacer.