Mep-803a water pump and stuck all the way to left fuel gauge

[The_DJ_Remixer]

Good morning everyone, I hope your day is going good. I picked up a 803a for a fair price, and I'm servicing it in preparation to install for my home backup. Water pump (or that O ring at the bottom) was leaking pretty good. I ordered a water pump, found a video or two on youtube and will be installing it this week. Any tips/tricks I should know about before installation? Seems to be a fairly easy job. One question I had for anyone who's done the job... did you use any rtv or other on the pump gasket or thermostat gasket? I noticed the backing plate does not have a gasket available, so I'll use some fel-pro blue make a gasket material. Obviously I don't want it to leak, so RTV (or similar) or no?

I read up on the fuel gauge being sensitive on these machines. Mines pegged all the way to the left (below E). Read up that in most cases if its to the left, its either stuck or the sending unit is stuck or faulty, or perhaps wiring. Since I'm going to do the water pump job, I'd like to address the fuel gauge as well. I was reading up on threads here, but didn't get the exact answer I was looking for. If I were to replace the sending unit, I seen some folks using a 5.5 inch universal kit, but it leaves the gauge about a 1/4 tank off, so they say. These threads were a few years older. It seems that there are a lot more options in regards to sending unit length available now. Since I don't have the sending unit disconnected yet, wouldn't it be better to get a 6.5 or even 7.5 (if 8.5 is OEM?) length? I want to do this job once and be done with it. Some folks say that the 8.5 could rub and get caught up on the edge of the tank.

Finally, thank you all for your time. It's really nice to have an old school forum still active and moreso for these military machines. Take care and best to you!

 

[Guyfang]

Have you downloaded all the TM's for the gen set here in the forum? Before you start ordering things, its a better idea to test things.

The troubleshooting for the M5, (Fuel Level Meter) is simple. Keep in mind, that a miswiring of M5 is a fairly common thing. With the power to the control Cube turned off, the S17, (Emergency Stop Switch) pushed in, is the meter still in the same exact place?

If you do not look like an Olympic weight lifter, you should be able to reach in the tank and feel the MT5, (Fuel level Indicator) and move it up and down to see if the meter moves. Often the float is full of fuel, and naturally, will show a empty on the M5. Read the troubleshooting for this failure.

 

[flyfishtrailer]

Guy is right on. These machines sit for long periods of time and often need cleaning more than replacing of parts. I would also suggest that since you're going to be in the fuel tank, I would replace the well nuts now and save the trouble down the road Call me Colt has done several videos on his YouTube channel that are repairs and upgrades to 802/803 generators (I think he even did one on replacing the fuel sending unit).

 

[Guyfang]

I was in a hurry last night. I should have told you to simply take the front cover off, pull the MT5 out and look at it, test it, and then know its good/bad. Simple. Takes longer to get the panel off then to test it.

 

[The_DJ_Remixer]

Thanks fellas. I did down the tms, started to go through it. Another thing I want to do is test the glow plugs. Appreciate the info, have a good Sunday.

 

[Light in the Dark]

When you say the 'backing plate', I assume you mean call out #13? As you can see there is a plate to manifold gasket. If it were me, I would replace the water pump gasket, the gasket for the plate to manifold, and both O rings on the sleeve into the block.

 

[Light in the Dark]

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[The_DJ_Remixer]

Totally overlooked that gasket, thank you - its nice that it comes with the o rings too, good stuff!

 

[Light in the Dark]

Totally overlooked that gasket, thank you - its nice that it comes with the o rings too, good stuff!

It doesn't by that part number, but the seller is bundling them together... which is nice. Since you are already there, no sense in not refreshing all the gaskets/seals related to the pump.

 

[The_DJ_Remixer]

It doesn't by that part number, but the seller is bundling them together... which is nice. Since you are already there, no sense in not refreshing all the gaskets/seals related to the pump.

Already ordered. Im gonna do the water pump job later this week. Lots of other stuff to work on.

Someone mentioned a well nut. I haven't gotten that far on the TMs yet.. Without any knowledge about that part etc, am I to assume the well nut keeps the drain line from leaking? What if mine is not leaking? Do I have the right idea? I do appreciate your time!

 

[Light in the Dark]

The well will leak... Just a matter of time. Could be next month, could be six years from now, but it will.

 

[Ray70]

As for gasket sealer, there's nothing wrong with a thin layer of a quality gasket maker ( not pure silicone ) like Permatex, you can also use gasket shellac on the paper gaskets.
For the fuel gage, there's dozens of posts on here regarding replacing your float arm unit with a WEMA marine unit.
You want an 8.5" sender in your machine.
I usually suggest folks add a round plastic disc epoxied in place at the bottom of the sender to prevent the possibility of the float touching the side of the tank drop -off, but most people say they didn't need it.
I needed it once but it was probably because the top of the plastic tank was a little deformed, making the sender sit a little uneven.

 

[The_DJ_Remixer]

As for gasket sealer, there's nothing wrong with a thin layer of a quality gasket maker ( not pure silicone ) like Permatex, you can also use gasket shellac on the paper gaskets.
For the fuel gage, there's dozens of posts on here regarding replacing your float arm unit with a WEMA marine unit.
You want an 8.5" sender in your machine.
I usually suggest folks add a round plastic disc epoxied in place at the bottom of the sender to prevent the possibility of the float touching the side of the tank drop -off, but most people say they didn't need it.
I needed it once but it was probably because the top of the plastic tank was a little deformed, making the sender sit a little uneven.

Thank you for the info fellas! I'll be busy fixin this bad boy up all week.

 

[2Pbfeet]

Already ordered. Im gonna do the water pump job later this week. Lots of other stuff to work on.

Someone mentioned a well nut. I haven't gotten that far on the TMs yet.. Without any knowledge about that part etc, am I to assume the well nut keeps the drain line from leaking? What if mine is not leaking? Do I have the right idea? I do appreciate your time!

I like this version; the outer threads have a flat for a wrench, and it comes with an o-ring.

Brass Bulkhead Fitting 1/4" FPT I.D w/ 3/4" Required Tank Hole Size

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There are a few how tos on the site. I found inserting a wire from the bulkhead over to the filler and pulling the nut over to be about a ten minute job, but have a plan for how to retrieve/remove the wire. Pretty painless once the tank is empty. I found piece from at least one other well nut floating around in my tank, which need to be removed to keep them from plugging the fuel intake out of the tank.

All the best,

2Pbfeet

 

[The_DJ_Remixer]

I like this version; the outer threads have a flat for a wrench, and it comes with an o-ring.

Brass Bulkhead Fitting 1/4" FPT I.D w/ 3/4" Required Tank Hole Size

Buy Ace Roto Mold Mfg. Brass Bulkhead Fitting 1/4" FPT I.D w/ 3/4" Required Tank Hole Size - 10897 from Farmer Bob's Parts and Supplies starting at 16.95.

farmerbobsparts.com

There are a few how tos on the site. I found inserting a wire from the bulkhead over to the filler and pulling the nut over to be about a ten minute job, but have a plan for how to retrieve/remove the wire. Pretty painless once the tank is empty. I found piece from at least one other well nut floating around in my tank, which need to be removed to keep them from plugging the fuel intake out of the tank.

All the best,

2Pbfeet

Thank you! I gotta tell you guys.. very thankful to all the responses here. Finding out SS is a great community, I feel like its 2008 internet all over again!

 

[The_DJ_Remixer]

Spent some time on the 803a today. Entire cooling system was gooey and rusty. Anyone have a product recommendation that works to clean up the cooling ports? The backing plate that the water pump sits on is pitted to hell and back but I'm fairly certain the mating areas are fine. Plate's sittin in my parts cleaner over night. Going to test the "glow plugs" tomorrow. Also hoping to test the fuel gauge. I started to take the fuel tank out, but ran out of time today. The metal sleeve that the fuel cap screws on to is rusty as well. I got the recommended brass bulkhead fitting for the bottom of the tank. That's on the list.

 

[The_DJ_Remixer]

When you say the 'backing plate', I assume you mean call out #13? As you can see there is a plate to manifold gasket. If it were me, I would replace the water pump gasket, the gasket for the plate to manifold, and both O rings on the sleeve into the block.

View attachment 929455

Part 16... is this collar removable from part 13? I see the old red o ring on the engine side 15, but I don't see the front water pump side o ring. Does the front o ring sit on the water pump side, just inside the gasket and mount to the rear of the pump? This cooling system is/was really bad.

 

[Light in the Dark]

Yes 16 is just tension held in the block and this plate, by two O rings.

 

[The_DJ_Remixer]

Just to clarify, the piece that the o rings sit on, 16.. that is removable from part 13? Is the 2nd o ring sitting inside the 1/4 inch plate on the collar? I just want to be sure before I start tapping on it to get it loose.

 

[Light in the Dark]

If its free floating in the TM document, it means its a discrete part. Its only being held in place right now by corrossion and ex-wife level stubbornness.