Shurflo 2087-593-135 12v diaphragm pump 
M1/2 inch ports
Self-priming
10 amps
3.1 bar (45 psi) pressure switch
11.3 lpm (3 gpm)

The Shurflo story
Shurflo Pumps (USA) started business in 1968.
When the Shurflo company was founded, the recreation market was searching for a dependable fresh water pump to deliver water stored in tanks to the faucets, showers and toilets installed in the coaches. 
Shurflo developed a line of pumps that not only met the need, they worked so well that 25 year old pumps are still working today, hard and efficiently every time a faucet is opened. 
Shurflo has remained responsive to the changing needs of this industry that pumps built today are even quieter, draw fewer amps and are more efficient than those original pumps of the past.
Shurflo has been manufacturing electric motors for its own pumps since 1983. 
Each year over one million motors are manufactured. 
The same dedication to quality that has made Shurflo the leader in its pump markets has been applied to supplying motors to customers who need a dependable, experienced and innovative supplier.
The company routinely deals with agencies around the world and works with TUV and VDE to assure that its products are in compliance with the standards which have earned their CE mark. 
Shurflo has files with UL, CSA, NSF, SK and several others. 
In 1993, Shurflo was the first pump company in North America to earn ISO-9001 registration.

Troubleshooting 12v diaphragm pumps

The pump does not prime?
Lets go through a process of elimination to try and identify the problem:
Is the pump motor running?
 - if not it would appear there is an electrical problem - check the wiring and connections
The motor is running but the pump is not priming:
- at the end of spray lance is an adjustable nozzle – remove the nozzle and see if spray comes out (nozzle could be blocked)
- remove the discharge hose (gun hose) from pump – see if spray comes out of pump (may be air lock in hose?)
- is there a blockage or kink in the discharge hose (gun hose)?
- remove suction line from pump – is it blocked? Or kinked?
- is spray being drawn up the suction line?