Drain the Crud From Fuel Tank?

[ProjectPro]

My C7 manual specifies that water and debris should be drained from the bottom of the fuel tank on a yearly basis. I can see the drain plug but am reluctant to do it myself just in case something goes wrong. I asked my local Caterpillar dealer to do it, but they declined. They told me that their customers just drain the water separator occasionally (the C7 book says to do that daily). I haven't seen any crud or water come out of the separator, and I do drain it a few times per year.

They said that if I really wanted them to do it, I would have to bring it in while it is VERY low on fuel. I guess their concerns are similar to mine, but they have a shop right there and plenty of mechanics to lend a hand if something goes awry.

So, wiser and more experienced diesel owners, do you drain the crud from the bottom of the fuel tank, and if so, how often? Do you do it yourself, and if so, how tricky is it to do?

The reason I'm concerned is that I clog the fuel filter on the Onan QD7500 regularly, and have to change it several times per year. I'm going to have Cummins look it over next month, but wanted to eliminate this as a potential problem source before I take it there.

[mel s]

Originally Posted by ProjectPro

My C7 manual specifies that water and debris should be drained from the bottom of the fuel tank on a yearly basis. I can see the drain plug but am reluctant to do it myself just in case something goes wrong. I asked my local Caterpillar dealer to do it, but they declined. They told me that their customers just drain the water separator occasionally (the C7 book says to do that daily). I haven't seen any crud or water come out of the separator, and I do drain it a few times per year.

They said that if I really wanted them to do it, I would have to bring it in while it is VERY low on fuel. I guess their concerns are similar to mine, but they have a shop right there and plenty of mechanics to lend a hand if something goes awry.
So, wiser and more experienced diesel owners, do you drain the crud from the bottom of the fuel tank, and if so, how often? Do you do it yourself, and if so, how tricky is it to do?
The reason I'm concerned is that I clog the fuel filter on the Onan QD7500 regularly, and have to change it several times per year. I'm going to have Cummins look it over next month, but wanted to eliminate this as a potential problem source before I take it there.

ProjectPro
I had my diesel fuel tank drained once at 75k miles but the shop warned me that they would not be responsible for any future drain plug or drain plug weld leaks that might develop.
(BTW very little crud was found)
Mel
'96 Safari, 144k miles

[byoslandry]

Originally Posted by ProjectPro

My C7 manual specifies that water and debris should be drained from the bottom of the fuel tank on a yearly basis. I can see the drain plug but am reluctant to do it myself just in case something goes wrong. I asked my local Caterpillar dealer to do it, but they declined. They told me that their customers just drain the water separator occasionally (the C7 book says to do that daily). I haven't seen any crud or water come out of the separator, and I do drain it a few times per year.

They said that if I really wanted them to do it, I would have to bring it in while it is VERY low on fuel. I guess their concerns are similar to mine, but they have a shop right there and plenty of mechanics to lend a hand if something goes awry.

So, wiser and more experienced diesel owners, do you drain the crud from the bottom of the fuel tank, and if so, how often? Do you do it yourself, and if so, how tricky is it to do.

The reason I'm concerned is that I clog the fuel filter on the Onan QD7500 regularly, and have to change it several times per year. I'm going to have Cummins look it over next month, but wanted to eliminate this as a potential problem source before I take it there.

If your generator filter is logging up several times a year, you have a lot of algae or trash in your tank. In general, the generator pick up tube is lower down in the fuel tank as they generally stop getting fuel at 1/4 tank. I've drained tanks before. I'd wait until you get as low as you can by driving it or siphoning out the fuel.. You'll need a container large enough to drain at least 5 gallons at a time and then put the plug in if you have a plug. You will get diesel on you and your wife will not like the smell :-) If you have a place to do it, you could buy an air over vacuum pump and pump the fuel out into a 55 gallon drum and then filter the trash and water out. Manually it's not hard if you can turn a wrench and have a place to do it.
I always start looking for a fuel station when I get to a half tank, so if I have to boon dock for the night unexpectedly, I'll always be able to run my generator if I need to.
Whatever you do be safe and drive carefully.
Byron
04 Newmar Mtn Aire DP 4016 FOR SALE :-)

[mel s]

Originally Posted by ProjectPro

My C7 manual specifies that water and debris should be drained from the bottom of the fuel tank on a yearly basis. I can see the drain plug but am reluctant to do it myself just in case something goes wrong. I asked my local Caterpillar dealer to do it, but they declined.

ProjectPro
If you are seriously concerned about crud in your fuel contact a commercial "fuel polisher"...like this: Fuel Polishing and Filtration Services - Clean Fuels
Or Google "diesel fuel polishing".

[twinboat]

Originally Posted by byoslandry

If your generator filter is logging up several times a year, you have a lot of algae or trash in your tank. In general, the generator pick up tube is lower down in the fuel tank as they generally stop getting fuel at 1/4 tank. I've drained tanks before. I'd wait until you get as low as you can by driving it or siphoning out the fuel.. You'll need a container large enough to drain at least 5 gallons at a time and then put the plug in if you have a plug. You will get diesel on you and your wife will not like the smell :-) If you have a place to do it, you could buy an air over vacuum pump and pump the fuel out into a 55 gallon drum and then filter the trash and water out. Manually it's not hard if you can turn a wrench and have a place to do it.
I always start looking for a fuel station when I get to a half tank, so if I have to boon dock for the night unexpectedly, I'll always be able to run my generator if I need to.
Whatever you do be safe and drive carefully.
Byron
04 Newmar Mtn Aire DP 4016 FOR SALE :-)

The generator fuel pickup is actually higher off the bottom of the tank.

That way you have fuel to run the main engine to the re-fuel.

[mel s]

Originally Posted by twinboat

The generator fuel pickup is actually higher off the bottom of the tank.
That way you have fuel to run the main engine to the re-fuel.

[Rook]

My motto.....if it ain't broke, don't fix it! 140,000 miles and going strong! Rook

[ProjectPro]

Mel - I have called a couple of local fuel polishers and they told me that they must have a straight-line shot to the fuel tank in order to get their wands (my term) inside to clear out the gunk. I don't have that - the fill lines curve on their way to the tank. The one polisher who seemed interested told me that he could do it if the tank was out of the RV, but his shop doesn't do the actual removal. The other person is a friend and recreational boat diesel mechanic. He used to do fuel polishing, but couldn't make any money on it and sold his polishing equipment.

[MnTom]

I believe you are worried about a non-existant problem. If you are not getting anything in you water separator or plugging filters, don't worry about it. I never drained any of the over the road semi trucks I drove and have 192k miles on my pick-up. The tank has not been drained in the 20 years the truck has been on the road.

[1ciderdog]

Apparently there is a problem. The generator filter clogs and needs to be replaced several times a year. I have no idea how or why that would happen since he
hasn't seen any crud or water come out of the separator.

[byoslandry]

Originally Posted by twinboat

The generator fuel pickup is actually higher off the bottom of the tank.

That way you have fuel to run the main engine to the re-fuel.

Twinboat

You are absolutely correct. I thought one thing and wrote another.. Old age thinking :-) I did mean to write higher than lower on that generator fuel tank pickup :-)
Thanks for correcting that so other people have the right information.
Drive safely
Byron

[wclogger1]

I just went through this process of draining my 2005 Journey in October. Mine was for a different reason though. I wanted to know how much fuel I had left when the FCC panel started flashing and telling me I was low. I ran it down to where it told me 9.8 gallons left. When it first starts to flash the analog gauge shows 1/4 and the FCC display shows 22.5 gallons. The unit is supposed to have a 90 gallon tank.
I used some bins I had that held 5 gallons each with some wiggle room. When I drained it I got 15 gallons out. There was no crud on the plug, nor rust nor water drops. This was at 39,000 miles.
I measured it as I was putting the fuel back in. The first 5 did not register on the FCC read out, the second 5 brought it up to 1.8 gallons and the third brought it up to 9.8. I now know I have no crud in my tank and I have an idea of where my level is when it gets down to the flashing display.
Bob

[mchero]

If you do end up draong the tank I'd like to know how much crud they find. Good luck.

[DMTTRANSPORT]

763,000 on the Truck and I can see nothing in the bottom of each 100 gallon tank.