Water/Diesel Questions

[hillbilly rick]

I noticed about a half of inch of water in my separator yesterday. I'm not sure how long it had been there - I'm still learning about diesel and tractors. I have just started using Power Service (white bottle). Most of the fuel in the tractor is treated. I have a couple of questions.

Should I change the fuel filter with that much water in the separator? I drained the water.

When changing the fuel filter, should you run the tractor after closing the shutoff valve until it quits to burn the leftover fuel, or is that bad for the engine?

I know you are supposed to keep the tank full to minimize condensation. Is that also true with a 5 gallon can? It is hard to keep both full. What is the best way to keep any water in the can out of the tractor - other than not using the can?

The building I store the tractor in is a damp area. This might be a cause of the problem. I do not have a better choice to park everything unless I keep it outside. I put 35 hours on it since May. I normally use it a little over an hour at a time. Does this usage pattern lead to condensation?

Thanks in advance for your help.

 

[greasemonkeyok]

1/2 inch does not sound like a problem unless you are getting that much regularly. It means the separator worked like it is supposed to. Check your 5-gallon container to see if it has water in the bottom. If so, drain and replace all of the fuel in the can.

You sometimes get water from the station where you buy diesel, so check your container after each purchase. If that happens, they have a bad system so go somewhere else. I prefer the heavy traffic truck stops for diesel purchases because their fuel is usually fresh.

You will hear different opinions about using a dispersant in diesel because then the water runs through the engine combustion rather than being trapped by the separator. I don't use additives, but that doesn't mean anything. Others here may have better info on additives.

 

[Qapla]

...When changing the fuel filter, should you run the tractor after closing the shutoff valve until it quits to burn the leftover fuel, or is that bad for the engine?

It is usually never a good idea to run the tractor "out of fuel" since it can cause the injectors to lose their prime. Re-priming some fuel injectors can be a real nightmare.

If the tractor is running just fine and not sputtering due to the water, just clean the filter and replace the cartridge if it is paper. The tractor should be just fine.

Make sure you clean your cans out good. If I am concerned about water in the cans, I will let them sit open where they are protected from rain and dew for a few days and let them completely dry out. Then I know there is no water in them on my end. If after filling them up I have water ... I find another station to buy my diesel.

 

[Gary Fowler]

No real fact study basis for this, just personal observation, but I think the plastic cans sweat less than metal. I have never found water in my plastic fuel cans that I use for gasoline, but I used to find water in the old metal cans all the time. I only use the pure gasoline with no ethanol so I know it isnt because the alcohol dissolves it. Any one have the same thoughts about that.

 

[Soundguy]

if you run out of diesel, then you get to learn how to bleed one.

once is usually enough

 

[Skyco]

A can that is properly sealed will not get condensation in it.
A vented container will.
If cans are getting water in them then check the cap, or buy different better cans.

To avoid getting water into a fuel tank use the Mr. Funnel, works great.
I've even pumped water contaminated fuel out, run it through the Mr. Funnel then put it back in.

 

[JimRB]

Home is a followup to Skyco's post. I never heard of Mr Funnel but it looks like something I might buy.

 

[hillbilly rick]

if you run out of diesel, then you get to learn how to bleed one.

once is usually enough

Mine is supposed to be self bleeding, but I don't think I will intentionally test it. I was just trying to minimize the mess. It is good to know that I should not get condensation in the "can". How does condensation get into a fuel tank? I know it does, but I don't know what path the moisture takes to get there.

 

[MHarryE]

In the fuel tank- as fuel is used it is replaced with air. Air contains the moisture, and the hot, humid air will have moisture condense out when it hits cool fuel. Sitting through a winter in a humid areA is especially bad as the fuel stays the same, but old air is pushed out as it warms in the day and new air with a fresh load of moisture is drawn in every night. The fuel keeps getting a higher water content. The worst places are humid areas close to seas and oceans. I had the benefit of being able to look at worldwide warranty data and damage due to water in the fuel was worst in the SE USA. AZ seldom see a problem. united Arab Emirates, Oman, Bahrain are really bad because of being on the Persian Gulf, having temps where the air soaks up a lot of moisture, and it can cool down a lot at night. Some of them can find a good (actually bad) amount of water to drain from their separator every day. I've seen dual separators mounted on some machines with fuel injection pumps particularly sensitive to water although no pumps like any water going through them.

 

[Skyco]

How does condensation get into a fuel tank? I know it does, but I don't know what path the moisture takes to get there.

MHArryE explained the process well.
As for how it actually gets in- Through the cap usually. Most have a vent built in. Either that or in the case of my diesel pickup, there is a 1/4" vent line running out of the top of the tank, and tucked up on the frame.

On my dirt bikes and ATV there is a hose attached to the cap for venting. I've often considered making some sort of silica gel canister to place in line to grab the moisture in the air.