Cat 310 pressure
When we looked at the wash about 6 weeks ago, the owner showed me what the truck bay pump/motor was doing. It had kicked the 3 phase breaker and he just shut it down. It makes a very loud noise when the pump turns on. Still produces 1500 psi, so it might be the motor. Taking the belt off and starting the motor (checking load/amps) will tell the tale. Either way it should be an easy fix.
2Biz,
You're on the right track and the forum here is helpful. Step by step diagnosis and patience will go a long way.
In addition to your motor test, this is a good time for a simple pump crankcase and bearing check; With the belt removed and a discharge port open, rotate pump pulley by hand for ease of rotation. Pump should rotate smoothly with minimal effort and no binding.
Some pump theory which may be helpful;
1) A pump produces flow, not pressure. With nothing connected to a pump discharge port there will be no pressure. Pressure is introduced to a discharge line based on the restriction of water flowing through a nozzle or multiple nozzles. Get your hands on a nozzle chart to view flows through various nozzle sizes at various pressures.......This is where the magic happens.
2) Triplex plunger and piston pumps are positive displacement. Pump gpm output will be based on pump rpm. Pressure in a discharge line is controlled by a pressure regulator or pressure unloader and protects pump from an overpressurizing condition. Water which is not needed to flow through a nozzle or series of nozzles to achieve pressure setting is automatically directed through the bypass port of the regulator or unloader. In a trigger gun application, the regulator or unloader reacts each time the trigger gun is actuated.
Good luck in your new venture!
Greg Thoennes
Sales & Tech. Support
Arimitsu Pumps