Jabsco 2.9 max fresh water pump irregular

[sailaboutvic]

If fitted a new Jabsco 2.9 max water pump some months back , worked well now rather then a smooth flow of water it become a irregular pumping action , shacking the pipes back and fro , now and then it works fine for a while , it not air , and there no leaks , any other ideas before I strip the pump down

 

[sailaboutvic]

Always like to report back once the problem found , scale in the tap , striped it , cleaned it , and all works fine now

 

[wiggy]

Had exactly the same problem, drove me nuts until I worked out what it was.