I found out that the sewer hose is getting damaged when inserted into the squire metal rear bumper.
I have added a plastic pipe with holes(to allow moister and smell escape) under the rear bumper to hold the sewer hose,it slips easily into it with out any damage.
I use the original bumper to store support for the sewer hose.
These supports are half a plastic pipes in 2 sizes so they can fit one into the other,length can be adjusted accordingly to the needs, this is achieved by drilling holes on both halves and sliding them to fit length needed,then use a bolt to secure the length.