I am working in a new 1.5 manifold for my 3 suction lines. In the process I am having difficulty with the elbow sweeps gluing to the sweep fittings. The main problems is that the sweeps would not glue properly as they push back as I am trying to hold them in place. For some reason, there is a lot of push back pressure from the fittings to the pipes. Do you happen to know how to solve this pressure problem? Can any one help me understand why this is happening? Since I am installing the Jandy valves to the sweeps I truly do not want to make a mistake because due to my limited space I do not want to ruin the valves in the process.