So I'm setting up a new van and where I,m putting the flojet pump the inlet and outlet would mean the hoses would be awkward .
With My motorised hose reel if I reverse the polarity ( black to red , red to black ) the reel rotates in the opposite way.
So My Question , If I done this on the pump would the pump flow in the opposite direction ( making a neater set-up for Me ,Where the hoses are concerned ) or would it blow the pump ?
Obviously I know Jack all about Electrics 
A 12v motor will not be damaged but it will run the other way around (in reverse). I don't know if that will upset the pumps ability to pump water or not. (Most pumps use a cam arrangement to operate the pump diaphram.)
All the motors we use in wfp will have carbon brushes and an armature with a commutator. In some cases, depending on the application of the motor, the brushes are not directly opposite each other - slightly offset. This gives the motor more torque in its given rotation, but when the current is reversed it gives less torque.
So a battery driven electric drill with screw driver options will have the brushes directly opposite each other so it has the same torque in both forward and reverse.
This carbon brush offset may be applicable with your pump as its clearly designed to run one way, as evident by the colours of the wires, usually red for positive and black for negative.
It was a good 12 years ago when I last opened my Shurflo pump, so I can't remember what the situation was with the brush offset. It was of no importance then. (The motor was in a sealed enclosure. The outlet hose developed a small pin hole leak and filled the enclosure with water. So I took the motor apart to dry it out.)
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