1, is it the pump..? Could it be the motor..?
2, possibly 'air' trapped inside the pump chamber, is the pump fitted with a vent-off..?
3, re-prime the pump and vent any trapped air.
I read about someone asking about barrier fluid pressure..!
Much depends on what your product is you are sealing against.
some seal require a 'Pressurised tank' or 'thermosyphon system' to control the 'balance pressure' inside the seal.
Pressure balance within the Double cartridge seal is in...
