MEP 004a stuff I couldn't find by searching

[deuce bigalow]

I acquired an MEP 004aas that was in quite a state of disrepair, like a lot of GL finds. With help from this site I have pieced it back to near-working order.

There are a few things that I have not been able to find/ figure out.

Low oil pressure switch. NSN 5930-00-621-7133

I think I found one for $110 and 6-8 week lead time.

I read this thread http://www.steelsoldiers.com/auxill...mep-003a-replacement-oil-pressure-switch.html and tried to find a similar aftermarket replacement for the 004 but have not had any luck.

Is there a way to jump the 4-pin connector to start the engine before I spend the money on the new switch?

I have already spent a fair amount on parts for a machine that may or may not work (I think I've heard this song before).

So by that same logic will the engine start and run without the fuel level sender?

It came out of the tank in one piece then fell apart, beyond repair. Oshkosh sells it for $113 but I want to hear the beast run first.

I thought it was wired to kill the motor when fuel got low, so mabey I need to jump the fuel sender wires also?

I will be picking up a couple batteries today and hopefully I can try to start this thing soon.

 

[PeterD]

I acquired an MEP 004aas that was in quite a state of disrepair, like a lot of GL finds. With help from this site I have pieced it back to near-working order.

There are a few things that I have not been able to find/ figure out.

Low oil pressure switch. NSN 5930-00-621-7133

I might have one lying around. I do have some sensors, not sure which ones however.

I think I found one for $110 and 6-8 week lead time.

I read this thread http://www.steelsoldiers.com/auxill...mep-003a-replacement-oil-pressure-switch.html and tried to find a similar aftermarket replacement for the 004 but have not had any luck.

Is there a way to jump the 4-pin connector to start the engine before I spend the money on the new switch?

I have already spent a fair amount on parts for a machine that may or may not work (I think I've heard this song before).

So by that same logic will the engine start and run without the fuel level sender?

It came out of the tank in one piece then fell apart, beyond repair. Oshkosh sells it for $113 but I want to hear the beast run first.

I thought it was wired to kill the motor when fuel got low, so mabey I need to jump the fuel sender wires also?

I will be picking up a couple batteries today and hopefully I can try to start this thing soon.

On the fuel level sender, it is more complicate. Not only does it detect low fuel, it also detects a full condition and controls the shutoff valve so the tank doesn't over fill... At least that is my understanding of how it works. It is complicated, as the injector and injection pump fuel return lines go to the day tank, and the day tank can feed from either the in=set tank, or from an external source (the fuel selector above the fuel tank fill controls this...)

 

[deuce bigalow]

Ok so I have made some progress on this project.

Thank you PeterD for the help.

I picked up a low oil pressure switch and fuel sender from Oshkosh Equipment.

I tried to run the fuel pumps to fill the day tank and all I got was a rapid clicking noise from the pumps. Before I buy new ones I want to make sure these are not fixable. Does this clicking symptom sound familiar to anyone? It does it even with the fuel solenoid and day tank switch unplugged.

Also does this generator need to have a load hooked up to start the engine? Or can I fire it up to test the engine without a load?

 

[Keith_J]

If the fuel pumps are the cylindrical type, they have a strainer on the bottom, 9/16" wrench removes them. Also, if the gaskets there are leaking, no fuel delivered, just clicking. They have a magnet in the bottom cap to trap rust too.

Clean the strainers, (Pro Shot Copper Solvent IV gun cleaning product that works fast here) and replace gaskets. Pumps should work, if not, the check valve in the middle can be serviced. Pull the retaining ring and remove the valve+o-ring.

 

[deuce bigalow]

Thanks Keith J I knew there must be something I was missing. Check valves sounds like a good possibility. I had already cleaned the strainers and the magnets. I will replace the gaskets and service (replace or clean?) the check valves in the pumps tomorrow.

 

[deuce bigalow]

I disassembled and cleaned the fuel pumps. They still make a rapid clicking noise which slows then nearly stops, but they seem to be pumping some fuel. I have at least some fuel getting to the IP.


Do these generators need to be grounded and hooked to a load before attempting to start the engine? It's almost ready to try cranking it over and I'm thinking it should at least be grounded first.

 

[PeterD]

I disassembled and cleaned the fuel pumps. They still make a rapid clicking noise which slows then nearly stops,

This sounds quite normal. The slowing is when the day tank is full, and no fuel is needed.

but they seem to be pumping some fuel. I have at least some fuel getting to the IP.

If you get fuel to the IP, then the day tank has fuel, and the filters are getting fuel from the pumps. Personally I'd guess the pumps are functioning correctly.

Do these generators need to be grounded and hooked to a load before attempting to start the engine? It's almost ready to try cranking it over and I'm thinking it should at least be grounded first.

No, they will start, and run without any connections at all. However, I think well all will recommend that you do ground it (the trailer, if an M-200A1 has a ground stud) as a general safety practice.

Most MEP-004A have the neutral bonded to the unit's frame, so if you are not on a trailer, check to see if yours is, and if so you can attach the neutral to ground if you want and get the same effect. AFAIK, there is no dedicated ground point in the generator, neutral bonding is just a wire to a bolt near the output distribution stud panel.

 

[deuce bigalow]

It runs!!! Thanks for all the help I couldn't have got this running without the help of this board.

First couple tries it just clicked. ****. One more try and it started to turn over then it fired right up.

Purred real sweet for a few seconds then oil pressure dropped and it shut off.

Oil blew out of the canister lid and there is now 2 gallons of 30W in the bottom of the ASK.

Now to figure out what went wrong with the oil filter. It has a new filter and gasket and its on tight, not double gasketed. I pre-filled the canister with oil which I thought was supposed to prevent this sort of thing.

Edit- wow **** gets edited? Thats not even that bad of a word. Sorry for my foul language.

 

[Keith_J]

What gasket did you use on the filter? Square section gaskets have a habit of getting installed with a half twist, they then blow out unless you over-tighten the bolt.

This happened a lot to those in the field when the TOC needed power yet it had been 100+ hours since last change. Small generators were exempt from Army Oil Analysis Program (AOAP, not to be confused with aircraft owners and pilot's organization) so every 50-100 hours.

 

[PeterD]

Those oil filter gaskets are a royal PITA, and I've had similar things happen to me (not that much, but I have blown almost a quart out before I noticed the leaking.)

My eventual fix was another cover I had sitting around, which had a gasket already installed. I used it (and that old gasket!) and it sealed up just fine.

Had that not worked, I was going to make a custom gasket from rubber sheet (from Grainger, they have stuff that is compatible with oil) and may yet do that when eventually that old gasket fails completely.

However, the old gasket didn't leak a drop in the last 24 hours of run time during the last outage.

BTW, have fun cleaning up the mess, at least you have now rust proofed your enclosure!

 

[deuce bigalow]

Well it's good to know I'm not the first person to have a problem with the oil filter gasket. Thanks again

I spread a bag of kitty litter in there to soak up most of the oil. Saturday I am going to finish cleaning what I can and try to get the filter to seal up.

Oh and I need to go buy some more oil.

Yes the floor is now rust proofed but as for the rest of the machine it's already too late. The ASK is pretty rusty and will need some work to get it repainted. This machine was in an Asian country before I got it, somewhere wet or near salt water mabey.

 

[PeterD]

Well it's good to know I'm not the first person to have a problem with the oil filter gasket. Thanks again

I spread a bag of kitty litter in there to soak up most of the oil. Saturday I am going to finish cleaning what I can and try to get the filter to seal up.

Oh and I need to go buy some more oil.

Yes the floor is now rust proofed but as for the rest of the machine it's already too late. The ASK is pretty rusty and will need some work to get it repainted. This machine was in an Asian country before I got it, somewhere wet or near salt water mabey.

In my case, cleaning out the kitty litter (oil-absorb) was a PITA too. I used the shop vac to get as much as possible, then took it outdoors (was working on it in the shop) and washed it well. There are drain holes, and Dawn dish washing soap does cut oil nicely.

My ASK is also got some rust (I think that is why they were surplusing these out...) and this winter while it is in the shop (it's winter home, since if I need it I don't want to dig it out of a snowbank!) I'll attack the worst of the rust. I do have two holes (one near the battery door), which will require patches, most of the rest is surface along edges such as the top covers, and the operator and battery doors.

 

[storeman]

Might I make a suggestion on treating your rust? there is a product called Ospho which is a phosphoric acid concoction which will make the rust inert and paintable. spray on rinse off. sold in gallons at about $20 gallon. We used it on the I-beams for my building and then painted them. "http://www.ospho.com". we carried it for years in our store because it takes rust stains off boats. good stuff. we are going out of business so I don't have it any longer.
Jerry

 

[Keith_J]

Phosphoric acid works. It is slower on heavy rust but enough applications will get a paintable surface. It will bleach CARC to a lighter shade so be careful.

I've soaked small parts in it for complete rust removal but watch out, it will remove good metal used in this fashion.

There are other brands which work the same. Plus the wash-off is a good fertilizer. One of the few phosphates not banned.

 

[deuce bigalow]

Phosphoric acid- that is what I need for this. I had heard of that before but couldn't remember what it was called.

As for the oil leak the gasket had slipped off the surface on one side, part of the gasket was inside the canister. I reassembled it a little more carefully and no more oil gusher.

This thing runs like a champ. I think I will need to put a load on it to bring it up to temp. 15 minutes with no load barely got it over 120.

The reverse power indicator was on also. Does this happen from running with no load? Or a poor ground? I didn't drive a real ground rod yet- it's gonna get hooked to the house.

The TM says this- "The reverse power indicator is an indicator lamp with a red
lens. It illuminates when reverse power exceeds 20% and the reverse power protective device actuates." But what does that mean?

 

[PeterD]

Make sure the parallel switch is in the correct position. Reverse power is when a generator is paralleled but not supplying the correct power. Running without a load won't cause it to light on a MEP-004, I do this for my occasional test runs sometimes when I'm too lazy to connect a load bank (my collection of electric heaters!)

 

[deuce bigalow]

Ran my MEP 004aas for a bit today, enough to bring the temp up.

I got a good reading on the voltmeter and frequency gauges so it must be making power.

The reverse power indicator is still lighting up though. The switch is set for single unit operation. Anyone have any ideas why this light is on or how to diagnose it?

 

[sewerzuk]

The reverse power indicator is still lighting up though. The switch is set for single unit operation. Anyone have any ideas why this light is on or how to diagnose it?

Might sound like a crazy question...but have you tried to reset it yet? I have worked on a few sets that developed spurious warning lights the first couple of times I ran them...
After the set is running, just hit the lamp test/reset button for a second or so. It should reset.

If it won't reset, I can guide you into a little troubleshooting...but it really isn't a necessary warning light for single set operation. You could just ignore or intentionally disable it...

 

[deuce bigalow]

Thanks sewerzuk I'm going to try running it again tomorrow and I will try the test/reset button.

A little more info from running it yesterday- I tried powering a load with no luck.

The voltage gauge says I am getting voltage and adjusts with the knob.

But the frequency meter pegs on the high side and the knob does nothing to adjust it.

 

[sewerzuk]

Thanks sewerzuk I'm going to try running it again tomorrow and I will try the test/reset button.

A little more info from running it yesterday- I tried powering a load with no luck.

The voltage gauge says I am getting voltage and adjusts with the knob.

But the frequency meter pegs on the high side and the knob does nothing to adjust it.

The fact that your voltage meter is reading is a good sign; I suspect that nothing too serious is wrong.

If you're trying to adjust frequency with the little knob on the control panel labelled "frequency adjust," it won't do anything on your generator. That control circuitry is nonexistent in utility sets...that little knob doesn't do anything except confuse people The way you should be adjusting frequency is with the throttle; black knob below the control panel on the right hand side.

If you tried to power something from the line terminals on the side of the generator, did you remember to close the main circuit breaker? The little light on the control panel should come on when the breaker is closed. However...if you truly do have a problem with your alarm circuitry, the breaker may not close...

Edit: if you have a DVOM, you should verify the voltmeter reading is correct by measuring output at the convenience receptacle below the control panel, and at leach of the 3 line terminals. Even better is to verify frequency...I have had quite a few sets with an inaccurate frequency meter. Depending on what you are trying to power, even just a few hz off and it may not work, or even worse become damaged.