Cat 30 pump pressure dropped to zero

[Randy]

My guess would be you've got an electrical problem. Get yourself a voltmeter and start tracing the 24 volt power that feeds the Dole valve.

 

[MEP001]

I have an update to this problem. It went away for a time, but now it's back. The problem only happens with high pressure soap. As in, when you select high pressure soap, the Dole Valve does not allow mixed water to enter the reservoir and it starves the pump. Select any other wash cycle and it's fine.

Is the small tank empty when this happens? The Dole solenoid is there only to fill the tank with water. If there's water in the tank, the problem is not with the Dole solenoid.

Also, I think the HP Soap check valve may be bad, I've noticed twice that a small amount of soap enters the reservoir and it makes the whole reservoir soapy. Probably not the greatest for the pump, I'm guessing.

If you're seeing soap in the tank, something is wrong. Soap is not ever supposed to be in that tank. The soap check valve is not there to keep soap out of the tank - it's there to keep weep from backing up into the soap lines. If you have soap in the tank and it's not empty and you're not getting pressure on soap, you have something backing up through the HP lines, through the pump and into the tank.

My thought is that I should be getting a 24V signal to the Dole Valve, but I'm guessing the voltage is not there. So I need to figure out what tells the dole valve to open when high pressure soap cycle is selected.

If the problem is the tank not filling, then you should get a voltmeter and start tracing the wiring back until you find the source.

 

[Jeff_L]

...it's been well below freezing for 2 weeks. The equipment room where the pumps are is nice and warm. Everything else with the car wash seems to be working ok. Bays 1,2 and Auto are all good, it's just this bay 3 pump. Thank you again for any help!

Is the line between the pump and wand frozen?