Vacuum question after upgrading pump on above-ground pool

I recently upgraded our pump on Summer Escapes 14'x42'" above ground pool to an Intex 2500 gallon filter pump 56633EG; old, under-functioning pump was removed from side skimmer, adapters were used to then connect new pump. Works great, maybe too great because now I'm unable to vacuum. When I attempt to vacuum the pool with the vacuum, hose and vacuum adapter plate the entire skimmer and hose collapses on itself. I don't have the plungers for the new pump but would prefer not having to spend another $150. Is there a cost effective remedy for this? Maybe a valve I should be opening? Thanks in advance for any advice, I'm new at this