School me on my water separator please

[hammick]

My 2002 MEP-802a with 150 hours has a NAPA fuel filter/water separator. I removed the drain today and got approximately 3/4 cup of liquid (tank has red dye diesel).

Can I assume that this liquid has a high percentage of water? If nothing comes out during future drains can I assume my fuel has little to no moisture? Is the purpose of the water separator to remove water or just alert you that you have a moisture issue and need to drain your tank?

The seller that refurbishedd my genset lives in a very humid climate. I will be installing it in a very dry climate.

Thanks.

UPDATE: I read the manual and it looks like I need to have the fuel system actively priming when I drain the water separator. I'll do that and report back.

 

[jasonjc]

If you have water, it will settle in the bottom of the filter. So when you drain the filter any water will come out first. If no water comes out you are fine.

 

[hammick]

If you have water, it will settle in the bottom of the filter. So when you drain the filter any water will come out first. If no water comes out you are fine.

Thanks. So fuel will always come out but if water is present it will come out first? I drained it again with the control in prime and run and got the a consistent supply of the same density fuel.

I'm guessing that if water is present it will eventually separate and sink to the bottom of my collection cup.

Looks like the water separator with the system in prime would be a faster way to drain the tank than using the gravity drain.

 

[Special T]

Draining and checking for water should be a key off exercise after letting the motor sit for a while. Key on or in close proximity to running agitates the fuel mixing the water and diesel. On my trucks I ususally just crack the valve a little and drain some off then check the oil before firing it off. I live in an are where humidity and rain are common and fuel/water mixed at the pump isnt uncommon.

 

[Daybreak]

View attachment 619947

Howdy,
A easy way to see what your after.

Take that measuring cup with the dyed diesel, and add 2 oz of water. Let it sit, and you will then see the separation. You will then know what water in the fuel system looks like when you do a quick drain.

Water (condensation) gets into the fuel system thru various ways. I always keep any vehicle topped off with fuel. The same applies for generators. When you have a half tank, and the air rapidly changes. Say from chilly, then a humid blast comes through, condensation forms and puts a bunch of water in your system. That really comes from sitting and not being used.

So, If you have your generator in place and not being used for a long time

check list
keeps batteries fully charged.
keep fuel full
keep oil full
exercise your generator with a load every now and then.

 

[JRM]

that diesel looks great, you would spot water in a second! Does anyone know how much the water sep filters the fuel or is the second cartage one that does all the filtering?

 

[st8drumz]

Ok, gotta jump in here. I know this is an older thread but I just drained my NAPA water separator/fuel filter on my deuce that I got late last July. I'm just getting up to speed with fuel system maint. Never owned a diesel before so the learning curve has been interesting. Here is what drained out of my filter. I was horrified. I've never changed the fuel system filters before and I have no idea the last time either of the two previous owners but from maintenance records it looked like it was being cared for well. Aside from running a half tank of old fuel oil that was run through a water block and 2 mic filters along with some PRI-D and Heet, I've only ever put pump fresh diesel into it. Anyway here's what came out. I've never seen it done before so I was expecting to see something that looked more like actual fuel

 

[st8drumz]

So, time to change the filter? Drain the tank? Again, no idea how old this filter is

 

[someoldmoose]

That is ABSOLUTELY the worst glass of beer I have EVER seen. With no other info that those few pixels on my screen I am gonna say, "DRAIN EVERYTHING, starting with the tank, blow out the lines ( with the air goin in AT the injection pump ) going BACK toward the tank. Let the "old" filters on for the first blow, remove the filters and blow again. Start at the IP and work your way back to the tank(s). Install the NEW filter / seperator, add FRESH fuel ( recommend veggie based Bio , as always ), prime her up and Letter Rip Tater Chip.

Radio Edit : What the pic appears to show is "glycerin" floating on top of good looking fuel. Where did the "glycerin" come from. Probably someone used untreated "bio" or similar "waste" in the tank at some point. You have a perfect cup of "that's what clogs the filters when it gets cold out", DO NOT DRINK THAT BEER !

 

[Bmxenbrett]

Drain the tank! And filters. If you regulary refuel this unit i would be looking for an external source for water entering the tank. Key hole in tank cap, pin hole in tank where the water runs over it or something along those lines. Also may have gotten a bad batch of fuel. Mabe fill a 5 gal can next time and take a look before it goes in the unit.
Thats alot of water but i guess it could be collected over many years since you dont know when the filter was changed last.

 

[Guyfang]

You are not going to like what I have to say. I had this problem in a PATRIOT Bn. Every gen set in the Battalion. Over 60 gen sets, of various sizes. We had stuff that made your sample look good. Everyone has told you to drain your system . They are correct. But if you want to do this right, you need to pull the fuel tank out and steam clean/pressure wash it. That's the long and the short of it. I would also remove the electric fuel pumps. Hook them up to a cup of cleaning liquid, I haven't the slightest idea what's available in the states now, but at least a cup full.

Then apply 24 volts to the pumps. Let the pumps circulate the entire cup of cleaning liquid. Remove fuel filters, and water separator. Clean it all out. Install everything, and then pump clean fuel all the way up to the IP's. You can pull the hose off there to let several cups of fuel flow out. Check it good.

Pulling the tank is a major PITA. But if you are using this gen set as your house back up, well, I could not sleep well knowing that I had not gone through this whole goat rope. That crap in your system needs to come out. A can or two of IP and nozzle cleaning liquid in the fuel tank would not be amiss afterwards.

 

[st8drumz]

Thanks Guyfang but this is from a Deuce and a half, not a generator (unless I'm confused about what you meant).  Great advice.  My understanding is that gas is great for cleaning diesel tanks

 

[someoldmoose]

First, I see no, or very minimal water in the pic. Fuel Floats on water. The light yellow stuff is some form of glycerin (floats on fuel if not in solution). Guyfang is right on the money. Although, I suspect you can get away without pulling the tank if ya get a good drain. Wouldn't hoit to, but unneeded IMHO. CLEAN everything ya can. If ya wanna pull any aux. pumps on her ya can. Run some methanol and gasoline through em. Just be careful and keep a CO2 or Halon extinguisher very handy. Gasoline is because methanol is invisible when burning in daylight. Need to get that "wax" outta there. You can throw some gas /methanol ( quart or two is plenty) in the tank and swish it around before ya add the FRESH fuel. It'll mix with whatever glycerin is still there after draining. As long as it stays in solution yer fine. Try to run her close to empty and refill before cold weather sets in though. That stuff clogs everything in the cold.

 

[st8drumz]

So any thoughts to share about replacing the 6 micron secondary filter (I have the single spin-on filter conversion) with a 2 micron filter? Would that restrict flow too much?

 

[someoldmoose]

6 BEFORE the 2 won't hurt anything and it'll keep "big" crap outta the 2 thereby extending it's life too. After the 2 is kinda pointless. If this is a "hobby" truck, I'd add the 6. If it's gonna be used often with lots fresh fuel then perhaps NOT. But why not ? It will only help. My $ .02.