The "sucking" or "squishing" noise you hear when the shocks are stroked is completely normal. 

The reason you are hearing this noise is that you are hearing oil being displaced throughout the damper as the shock is stroked. The purpose of the damper on the shock is to counteract the rebound of the spring after the shocks have been compressed. Without the damper, the shock would essentially feel like you are riding on a pogo stick. We use a damper filled with oil to counteract the rebound of the shock, and we counteract that rebound by making it harder for the shock to extend to its fully extended length (rebound) by using oil pressure or viscosity. As the shock is extended, there is a suction effect that takes place forcing oil to travel through various orifices in the damper which in turn creates a high viscosity or essentially "thickens" the oil, for a lack of a better term. This slows down how fast the shock shaft can extend, thus counteracting rebound after spring compression. If you have our REVO-A or AIR-A shock with rebound adjustment, you will notice this noise is louder as you increase the number on your dial. This is because on a higher number setting, the oil is forced to pass through a smaller orifice, which increases viscosity and pressure (more damping), and in turn increases the "suction" noise. If you were to not hear this noise, or not hear a change in noise between the different rebound settings, that would be a cause for concern, as the oil flow in this scenario is more than likely not being properly restricted, which would result in a degradation in ride quality because of the increased rebound and lack of damping.