mep 002A Aux pump

[metalworker393]

Hello and how are you all doing. Have a question I could find the answer to in the TM's . I'm doing the PMs on my 002a ,changed the oil and moving to the fuel system. P1 and P2 are working well. I cleaned the screens in the bottom of the pumps last year and haven't had an issue. My question pertains to the auxillary pump. The pump is barely clicking when turned on. It worked well several years ago when I was without power during Sandy refueling from a 55 gallon barrel.
I would like to know how much voltage should I see at the connector for the solenoid ? I have a Fluke meter to check it, don't know what it should be. Want to also make sure the solenoid isn't malfunctioning. After work today, I'm going to remove the bottom cover and check the filter, then remove the solenoid valve and see if it pumps. The machine has a little over 1200 hours on it, and, it may be a bad pump as well. I don't have a spare pump so I ordered 1 yesterday. It would be good to stock 1 anyway.
Thanks, metalworker393

 

[Light in the Dark]

You should see 24V when the switch is set to prime + aux. Try this, take the power off your primary pump, and put it to your auxiliary, and set the switch to prime + run... any difference?

 

[metalworker393]

Should I also see 24 volts at the solenoid connector?

 

[Light in the Dark]

The entire fuel system runs at 24V DC natively, so yes. Before you get into worrying about the solenoid, if the main pump sounds great on the normal run circuit, just swap wires over to test (or take the aux wire off the aux pump and put it on the main pump, but set to prime + aux... same end goal, different set of data). If your other pumps sound fine when running in normal mode, I don't suspect its the solenoid.

 

[Light in the Dark]

Are these original pumps, with the EMI filter still in place?

 

[metalworker393]

Yes they are the original pumps. The unit runs good, and I am considering replacing them just as a preventive maintenance measure so they don't fail when needed. The outside of the pumps are getting some surface rust from age. I have the generator set up inside my shed to keep it out of the weather. I cut a hole in the back wall of the shed and installed louvers with screens. I also have it setup on a double layer of 4x6 wood beams to get it up about a foot off the shed floor. Keeps it out of the weather, and has been keeping the mice out of it too. ( they destroyed the wire harness in my lawn tractor) Having it in the shed really cuts down on the noise while running.

 

[Light in the Dark]

Don't replace a functioning pump. Inventory backups? SURE... but dont replace a good pump. What I threw out there is a no cost option for testing. Let us know what you find. We may have a few tricks up our sleeve yet to diagnose this.

 

[metalworker393]

Hello and good morning to you all. I had some time last night after work to continue on this. I had power at the pump and when turned to the aux position, I could hear the pump run barely a second or 2. I decided, first check the filter. found a little debris in the bottom. Nothing major. Then I decided to remove the solenoid valve and plumb it up to the line to my tank. I hooked my aux line up so I could recirculate fuel from the tank. Pumped like there was no tomorrow.
My tank is half full, I'm not sure if the float switch just opens and closes the solenoid valve or does that also effect weather the pump operates in the aux run position. I get it wont operate in the normal run position, but does the float switch shut the pump off too when running in aux position? If not then the solenoid is dead ending the pump until the level drops so that that the valve opens and allows more fuel to be pumped into the tank.
Thanks, metalworker393

 

[DieselAddict]

The float only opens and closes the solenoid. The pump runs full time when in AUX/Run. When the pump reaches maximum pressure with no flow it clicks very slowly. That is normal. The clicking will pick up its pace when it starts moving fuel.

 

[Guyfang]

You can test the solinoid by pushing the float down, or by looking at the schematic, figuring out what contacts you need and jumping the switch at the plug. Very simple.

There is a very good explanation of the fuel system, and a diagram of the interconectivety, in the operators TM.