When pipelines are used to transport waxy crude oils in cold environments, the pipelines may become plugged with wax gels during periods of flow shutdown. It is a common practice to dislodge these gels by application of upstream pressure ("gel restart"), because the gel will fracture when the wall shear stress, proportional to the local axial pressure drop, exceeds the static yield stress of the gel. To better understand this process, we present results for the axial pressure profile measured as a function of time for a model waxy crude oil in a laboratory flow loop. Results are presented for both gels formed under ambient pressure and gels formed with a constant upstream pressure applied to minimize gas void formation. Gels formed in the latter case are more difficult to dislodge from the pipeline. The axial pressure profile in the gel just prior to a restart attempt depends upon the duration of the flow shutdown period. If a restart attempt is made soon after the oil gels, then large wall shear stresses arising from the axial pressure gradient are present in the gel. On the other hand, if the gel is aged for a long time prior to a restart attempt, then the axial pressure gradient approaches zero, a result that we attribute to a minute Darcy-type flow of the liquid components of the wax gel.