Draining fuel tank (split from Re: Coach PM Punch List)

Topic: Draining fuel tank (split from Re: Coach PM Punch List) (Read 1260 times) previous topic - next topic

Draining fuel tank (split from Re: Coach PM Punch List)

December 04, 2010, 04:37:44 am

Quote from: Barry Beam – December 03, 2010, 11:19:33 pm

Drain water and contaminants from bottom of fuel tank.

Where is the drain valve to do this?? Have often thought about draining, but do not see a drain.
That was a preflight item on ALL aircraft.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #1 – December 04, 2010, 08:44:52 am

Quote from: Bill Chaplin – December 04, 2010, 04:37:44 am

Quote from: Barry Beam – December 03, 2010, 11:19:33 pm
Drain water and contaminants from bottom of fuel tank.

Where is the drain valve to do this?? Have often thought about draining, but do not see a drain.

Here is a photo of mine. It is under the fuel tank.
There is NO WAY of unscrewing that bolt and not getting fuel all over you.

I have thought about adding a nipple to extend it down to allow easier access and make less of a mess.
Maybe Brett Wolfe has an easier answer on this one.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #2 – December 04, 2010, 09:03:43 am

It looks like the plug is very close the bottom of coach, there are not many real good answers as I see it,
A drain valve like used on the air tanks might be one answer, remove the lanyard , you could just push the valve sidways and drain some. Not sure how open it would be to running over things on road that could open it a little, if it is in good shape, it should close after hitting trash on road ?
Does n ot appear to be a good way to plumb it over to the side with a valve. Screwing a valve in the tank, would stick down tooooo far. so back to the air drain with lanyard removed

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #3 – December 05, 2010, 10:20:27 pm

I don't worry about draining my fuel tank. Since the fuel pickup is at the bottom of the tank, it is always sending water and contaminants to the fuel filters. Remember that the bottom of the tank is FLAT. So the only effective way to clean a tank seriously contaminated is to pump it out and through a fuel polishing system like you find servicing marinas.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #4 – December 06, 2010, 11:32:23 pm

After seeing some of the stuff that was in the bottom of a 5 gallon diesel fuel container I seriously thought about draining my tank. There are two problems which I will have difficulty overcoming. First, I probably still have 50 gallons of fuel left in the tank at this time. Second, not only would I be concerned about getting fuel all over me when trying to drain the tank, there is also the issue of trying to capture all that fuel without creating a environmental spill. I should mention that my tank is between the chassis rails and there is a four foot (!) pipe with two 90 degree elbows between the tank and the fuel cap making siphoning impossible.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #5 – December 06, 2010, 11:49:46 pm

If fuel is flowing properly and fuel filters are not clogging, I would not be inclined to clean out a fuel tank. Am I missing something important?

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #6 – December 08, 2010, 12:06:05 pm

Quote from: Lewis Anderson – December 07, 2010, 08:23:17 am

Discovered that I had a fuel leak ... only when under pressure.

Good thing you caught that. Those often are the cause of fires while going down the highway!

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #7 – December 14, 2012, 06:30:22 am

What is the fuel tank made out off,, Is it plastic or steel, its hard to tell from just looking at the drain hole and nut,

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #8 – December 14, 2012, 06:39:48 am

Metal, at least mine is.
Good luck on your project
Dave M

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #9 – August 18, 2014, 10:59:24 pm

Quote from: Bill Chaplin on December 04, 2010, 01:37:44 AM
Quote from: Barry Beam on December 03, 2010, 08:19:33 PM
Drain water and contaminants from bottom of fuel tank.

Where is the drain valve to do this?? Have often thought about draining, but do not see a drain.
Here is a photo of mine. It is under the fuel tank.
There is NO WAY of unscrewing that bolt and not getting fuel all over you.
I have thought about adding a nipple to extend it down to allow easier access and make less of a mess.
Maybe Brett Wolfe has an easier answer on this one.

I wonder if you could install a Curtis Drain Valve like the ones on aircraft tanks. It might take the fabrication, but would definitely make it easier to drain.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #10 – August 19, 2014, 01:00:16 am

Use a drill pump with a copper pipe that touches the bottom of fuel tank to suck out from bottom. Don't stir things up as you put pipe down. Pump out into a large glass jar, let jar sit for a couple of days. Good if all the same color, water on bottom, fungus between water & fuel level. Don't open bottom drain as fuel running on top of bay floor will get into Styrofoam between floor and destroy all insulation, and the smell will not go away.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #11 – August 19, 2014, 08:31:14 am

Mine drains itself really fast, all I have to do is crank the engine!

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #12 – August 19, 2014, 03:32:22 pm

Lean the coach over to the side that you want to drain from. This will make any water settle on that side.

You can use a drill pump or just siphon if you like the taste of diesel!

Keith

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #13 – August 19, 2014, 10:34:01 pm

I like the plan for leaning the coach and pumping from the low side to a glass container. Simulates what pilots do in preflight.

If the glass container is big enough, you should catch all the water, dirt, fungus and have some good fuel to pump back in (through a filter).

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #14 – August 20, 2014, 07:47:19 am

I made a small pump/ siphon using an outboard motor fuel line squeeze bulb with a piece of cpvc hard pipe to put in the tank and soft hose for going into the collection container. Give the bulb a couple of squeezes and it will free flow as long as your container is lower than your fuel tank--- works well and is simple and cheap.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #15 – August 20, 2014, 11:55:36 am

I did drain mine out, It is quite easy to do, Large flat tray under to catch excess, Put your finger in the drain hole when you want to change containers,

Make sure you have plenty of containers handy, I was struggling to find containers to store it in,

I drained approx 37 Gallons out of it, about fifty gallons brings it up to the empty mark on the fuel gauge,

I strained it all through a cotton cloth putting it back in the tank,

Its a lot easier if the coach is up on ramps, Very hard sitting on the road, You need the gap under there, It helps if you have two people doing it, Just to change the containers,

Having clean fuel, Stops a lot of the worry, and clean filters too,

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #16 – August 20, 2014, 12:54:27 pm

Easy way to relieve the worry is to install a Sufficiently large Raycor filter / water separator . If there is water, you can see it in the bowl, and the filter is very efficient with all other trash. I use the 10 micron filters. Change the filter when you change your oil and you wont have any trouble.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #17 – August 20, 2014, 09:33:05 pm

I use an additive every time I fuel up to (among other things) remove any moisture from the fuel. Haven't seen any moisture in the fuel or filters in the many years we've owned the coach. I always keep the fuel tank full when stored. Have a great day ---- Fritz

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #18 – August 20, 2014, 09:52:52 pm

The problem with relying on a water separator is algae will grow in the water/fuel transition and their residue is extremely acidic. The acid is what causes tank leaks. Using an algaecide like BioborJF, prevents algae growth till the water can be removed. Years of fixing aircraft fuel tanks has convinced me that preventative treatment is cheap.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #19 – August 21, 2014, 03:39:48 am

I had a 1990 city bus I played with for a few years. It came from Minnesota. It was rusted out when I got it, and got rustier as I owned it. Then I parked it for 5 years and eventually scrapped it.

Before scrapping it, I cut a hole in the side of the tank to pump out all the diesel (hey at $4 a gallon....). I was just going to use it to start fires, etc as I figured it would be nasty and dirty. Much to my surprise, the inside of the tank was spotless and the diesel was clean. No rust on a steel tank!

There was no sludge, gunk, or other nasty at the bottom of the tank or in the baffles.

Chances are, your tank is cleaner than you think it is. Especially if you actually put miles on your RV.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #20 – August 21, 2014, 05:12:04 am

Most of my bad fuel experience comes from boats----bad fuel is the norm in the Caribbean. If you don't get a bunch of water and green gunk with your fuel purchase there, you are extremely lucky indeed. I use a Racor 900 gal/hr filter / separator , not because I am flowing that much fuel, but to increase the filter change interval. In fact, I use two of them manifolded together with valves to switch from one to the other while the engine is running. I also use a Cummins Fleetguard product called Asphaultine dispersant that takes care of the low sulfur fuel Asphaultine and biologics / algae. It works well for me. The boat carries 450 gallons of fuel and sits for long periods in the Caribbean heat ( while I'm on the coach here). In addition, when purchasing fuel both here and in the Caribbean, I try to make sure that I am buying from a high volume source-- the more rapid their inventory turn over the less chance I have of buying bad fuel. If you start with clean fuel, you have a better chance of keeping it that way.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #21 – August 21, 2014, 11:53:39 am

I am wondering about building a fuel scrubber that you could put inlet in one fuel filler and the return on the other fuel filler. If the inlet was long enough to reach the bottom of the tank, the return agitation would keep the sediment moving enough that it would eventually clear the tank. You could let the system run overnight or over a weekend and you would eliminate the tank contamination.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #22 – August 21, 2014, 12:47:36 pm

Quote from: sedelange – August 21, 2014, 11:53:39 am

I am wondering about building a fuel scrubber that you could put inlet in one fuel filler and the return on the other fuel filler. If the inlet was long enough to reach the bottom of the tank, the return agitation would keep the sediment moving enough that it would eventually clear the tank. You could let the system run overnight or over a weekend and you would eliminate the tank contamination.

I was thinking along similar lines. Adding an external electric pump and filter. You could modify one of the filler caps with holes for the two hoses, the intake being flexible and weighted to lie on the bottom of the tank.

Re: Draining fuel tank (split from Re: Coach PM Punch List)

Reply #23 – August 21, 2014, 12:49:04 pm

That's what I have on the boat. I installed a manifold valve system and a pump. I pump through the filter and have the output valved into the fuel return line. On the Cummins, I think all you need to do is add the raycor and rewire a switch to the existing purge pump-- should work. It would then pump through the filter and back through the injector return line.

Affiliate Notice