A pop-up wheel device for use in material handling equipment. In one embodiment, the pop-up wheel device includes a housing, which is a can of generally track-shaped transverse cross-section. A nipple is mounted in the housing bottom to permit fluid under pressure to pass to and from the interior of the housing. A cap, which includes a central opening, is positioned over and is secured to the housing. A piston is slidably mounted within the housing between a lower position and an upper position. A seal is fitted around a lower portion of the piston and creates an air-tight chamber between the piston and the housing. A spring biases the piston towards the lower position. A wheel that is freely rotatable in one direction is coupled to the piston using a wheel mount. The wheel may be removed from the wheel mount without removing the cap from the housing.