2004 HR Scepter diesel tank dimensions, capacity and how should I modify the filler necks for better fill

[ok-rver]

Probably most of the mid 2000 and maybe latter MHs have a nominal 100 gallon diesel tank that is the full width of the chassis and can be filled from both sides. My tank has around 2" diameter threaded caps at each side that screw on to a short metal tube. A hose is then used to connect to the boss on the tapered side of the tank. There is only 1" of rise between the entrance to the tank and the end of the fill tube. An Autodiesel pump nozzle will not stay in the fill tube so you have to hold it thru all 60 or so gallons of pumping. Usually the nozzle will shutoff just after the diesel enters into the tube. Occasionally, the nozzle does not shutoff until a small amount of diesel over flows. Has anyone found a hose that can replace the straight section and would curve the outside tube up a bit to have a better chance of the nozzle shutting off?

I measured my tank several months ago to get an idea of capacity. There have been a few times when it has been filled at an angle and more went in than would have been expected by the gage reading. In the diagram attached, the calculations show that each inch of height in the tank is about 6.5 gallons. Some of the slopes at filling stations would have the MH 2" to 3" tilted away from the fill side which might account for the extra 15 or so gallons. There has also been discussion about leaving a reserve air space above the liquid level. Looks like maybe 18% capacity above when filled to the bottom of the neck. 

[vito.a]

I use the HWH air ride/leveling system to raise the side of the coach I'm filling and lower the opposite site.  My wife says it looks strange but it makes it much easier the fill and adds several gallons to the capacity.  

[Onrecess]

I have a 2003 Sig with a 150 tank. It holds about 120 level. If I tilt the heck out of it, it takes another 25 to 30. As far as the fuel pumps, truck stops have bug nozzles that stay in and fill much much faster. The skinny gas station's you have to hold the whole time. I have a TSD card, so the 15%plus discount drops to the cheap gas stations. The fuel is used pretty fast at a truck stop, so I hear it is cleaner, as all the crud settles in a tank if it sits a long time. At any rate, a fill up 4 or 5 times as fast gets my vote.

[Ivylog]

I agree this is not a very good design but easily solved if you have air leveling.
I’ve put 160 gallons in my 150 gallon tank by leaning the MH… works better filling on driver’s side as the tank’s air vent is on that side. I do not do this if stopping for the night close by, except in the winter.

Unlike my Dynasty, I had problems with the small nozzles I usually use coming out of our Navigator’s tank. Adding a saw blade to the bottom of the fuel door solved the problem, NO, I don’t stand there as I do a walk around temping tires, brakes, and wheel bearings plus cleaning windows while fueling.

https://www.irv2.com/forums/f258/fuel-spill-when-filling-422869.html

[Dr4Film]

I do the same as others who have Air Leveling. I lower the coach on the opposite side where I plan to fill. I can put in a significant number of additional gallons of fuel especially at pumps where the price is really low compared to other locations along my travel route.

Looks strange but it's cost effective.

[Cubflyer]

Rotate the nozzle 180 degrees (upside down from 'normal') and with the door mine stays in the tank just fine without me holding it.....

[Ivylog]

On 12/6/2021 at 11:38 PM, Cubflyer said:

Rotate the nozzle 180 degrees (upside down)

Does it shut off before spilling fuel? If a station is not busy and if the pump on the other side of the same pump has diesel too, I’ll put 2 nozzles in the same nipple (tight fit and not going to fall out) as I’m usually getting 120+ gallons.

Edited December 9, 2021 by Ivylog

[Guest Ray Davis]

12 minutes ago, Dr4Film said:

I do the same as others who have Air Leveling. I lower the coach on the opposite side where I plan to fill. I can put in a significant number of additional gallons of fuel especially at pumps where the price is really low compared to other locations along my travel route.

Looks strange but it's cost effective.

I lower one side too.  It does look odd, I can see people looking, like what is wrong with your RV.

I recently let myself get lured by cheap fuel.  The place looked ok and had a small truck island, but soon after filling up I thought it didn't feel quite right and then it stumbled slightly so I pulled my primary filter.  The filter had what I would describe as trash, not slime or goo but black particles, the sort of stuff that a hose might      give off when the inside crumbles.  A couple of filter changes and all seems good, never did change the secondary filter. I felt like the stuff was too coarse to get that far.  I'll go ahead and change both.  Fortunately, I wasn't running the gen, I hate changing that filter. One of these days I'll install a filter outside of the gen like Chuck B did.

While I was there a woman pulled up got out and said she needed help, her mother was in the hospital, and she desperately needed gas, so I gave her $5.  She didn't buy any gas at least not there, she left in a ferocious hurry, probably to find her dealer.  I think I was suckered twice that day.  Oh well, I am still blessed

[Cubflyer]

4 hours ago, Ivylog said:

Does it shut off before spilling fuel?

So far it has shut off every time, no fuel spill.....  upside down nozzle kind of acts like a fish hook, rather than a slinky...

[Paul J A]

On 12/7/2021 at 9:13 AM, Ray Davis said:

I lower one side too.  It does look odd, I can see people looking, like what is wrong with your RV.

I recently let myself get lured by cheap fuel.  The place looked ok and had a small truck island, but soon after filling up I thought it didn't feel quite right and then it stumbled slightly so I pulled my primary filter.  The filter had what I would describe as trash, not slime or goo but black particles, the sort of stuff that a hose might      give off when the inside crumbles.  A couple of filter changes and all seems good, never did change the secondary filter. I felt like the stuff was too coarse to get that far.  I'll go ahead and change both.  Fortunately, I wasn't running the gen, I hate changing that filter. One of these days I'll install a filter outside of the gen like Chuck B did.

While I was there a woman pulled up got out and said she needed help, her mother was in the hospital, and she desperately needed gas, so I gave her $5.  She didn't buy any gas at least not there, she left in a ferocious hurry, probably to find her dealer.  I think I was suckered twice that day.  Oh well, I am still blessed

Ray

I changed the Genny fuel filter to the same one as the AQ uses, and mounted it on the rear Genny enclosure panel. More that adequate GPM flow.

Edited December 9, 2021 by Paul A.

[W7BE_Bob]

I have the same basic tank, 130 gal, fills to 100 gal level. Tilted with air leveling can add up to 20 gal additional. Can fill from either side but see no reason to use the truck slave pump.

Check that your overflow hose is not clogged. HOWEVER I suspect that your problem is related to using a car type diesel pump, although I've never had any issue with one. Find a way to hold the nozzle in place like a custom fitted piece of wood, etc. My MH has a small fill door  that's mounted on a much larger door. It was much easier to open the large door to fill.

BTW my Jeep has a significant and know gasoline fill design issue and I'm going to search for a solution this winter.

[Guest Ray Davis]

I'll caution everyone about the fuel fill on the other side, it can spill disaster.  If the cap is loose, it can leak, and if it's off fuel will come out as fast as you put it in the other side.  It's been done before.  Walk away and wow no telling how much you could spill.   They really don't like spills either.  A big spill could even land you in trouble with EPA, and those are serious people, no humor at all.   Semis have separate tanks right & left, they can fill from both sides at the same time.

 

[Cubflyer]

I guess I'm missing the reason to put 120 gals of fuel in a 100 gal tank (by tilting it to the side) when I can't drive 100 gallons out of my tank in a driving day..?? Not to mention the $ cost of over 50 gals at a time....  Risking the spill of a $3 plus a gallon product is beyond me.... 

 

[Dr4Film]

Been doing this for years. There is no risk if one has even a smidgen of common sense.

I stock up on fuel when I am at truck filling stations that have fuel significantly cheaper than any other location on the route to my final destination.

[W7BE_Bob]

X2 Dr4Film. Don't get your point of cost of 50 gal? Buy 50 gal at a time and you're buying the same number of gallons but with multiple fuel stops.

 

[Cubflyer]

30 minutes ago, Dr4Film said:

There is no risk if one has even a smidgen of common sense.

Are you saying that anyone that questions the reason to overfill a fuel tank 'lacks even a smidgen of common sense'?

Common sense, in my opinion, is to fill a fuel tank, not to overfill a fuel tank.  But if you can do it for years and years without incident, you are my hero.

Next time I am filling up with fuel at a good price I'll have to tilt my rig, and fill it to over capacity to prove I have even a smidgen of common sense.

This tread started out with concerns of the nozzle not staying in the tank while filling and not shutting off without fuel spilling out first, and somehow has been turned into how to put more fuel in the tanks.

 

[willbo777]

3 hours ago, Ray Davis said:

I'll caution everyone about the fuel fill on the other side, it can spill disaster.  If the cap is loose, it can leak, and if it's off fuel will come out as fast as you put it in the other side.  It's been done before.  Walk away and wow no telling how much you could spill.   They really don't like spills either.  A big spill could even land you in trouble with EPA, and those are serious people, no humor at all.   Semis have separate tanks right & left, they can fill from both sides at the same time.

 

Are you saying watch out for the fuel cap to leak if you tilt while fueling, then why doesn't it leak going down the road, sloshing around as it does?  I tilt and have been tilting for a long time, like someone else mentioned I don't do it if I only have a few miles to the next campsite.  Never had a problem.  Can't understand why it isn't good to put a few more gallons in your tank no matter how big it is to begin with.  Means more miles until the next fill, and especially useful if it gets into another state where diesel is a lot cheaper.  My two cents.

[Guest Ray Davis]

17 minutes ago, willbo777 said:

then why doesn't it leak going down the road, sloshing around as it does?

If it's not tight it probably does leak.   I tilt too, have been for a long time.  Ivylog ( Dick ) mentioned using 2 nozzles, I think he meant in the same hole on the same side.  He didn't elaborate and it wasn't clear.  So, in case someone thought they can fill from both sides at the same time I wanted to caution them.  It really doesn't have anything to do with tilting.  I try to fill when I get down around 1/2 tank, I don't want to be low and looking or stranded.   I remember Bill G liked to try to drive a 1000 miles on a tank.      Not me, I'm ready for 2 breaks and an overnight maybe 2 overnights.

 

On 12/7/2021 at 5:52 AM, Ivylog said:

Does it shut off before spilling fuel? If a station is not busy and if the pump on the other side has diesel too, I’ll put 2 nozzles in (tight fit) as I’m usually getting 120+ gallons.

 

[Dr4Film]

27 minutes ago, Ray Davis said:

 I remember Bill G liked to try to drive a 1000 miles on a tank. Not me, I'm ready for 2 breaks and an overnight maybe 2 overnights.

Ray, 1000 miles would be 3 overnights for us. On a full tank I will do two days of driving and one overnight. I always fill before parking for the second night otherwise my generator and Aqua-Hot will quit. Monaco installed those pickups really high in my 128 gallon tank. There are only 100 gallons of usable fuel.

I know that because I ran the engine out of diesel one day. 😇

[Guest Ray Davis]

2 hours ago, Dr4Film said:

Ray, 1000 miles would be 3 overnights for us. On a full tank I will do two days of driving and one overnight. I always fill before parking for the second night otherwise my generator and Aqua-Hot will quit. Monaco installed those pickups really high in my 128 gallon tank. There are only 100 gallons of usable fuel.

I know that because I ran the engine out of diesel one day. 😇

Yep, 3 overnights sounds even better

[Onrecess]

First, the chance of the fuel cap I never use being magically loose doesn't exist. Second, my 2003 Sig manual says NEVER fuel both sides at once, it will spill. I thought my Guage was bad first few times out. I filled one day and the next stop my computer said I had over a quarter of a tank. I then ran out of fuel. That is when I started tilting. Now I have a real 150 gal tank. I have never lost a drop from the vent or either cap. I would not fill it that way and park in the sun. I doubt if expansion would run fuel out the vent, but I  don't fuel right before arriving.  Look at the tank design. Without standing the rv on its side, there is always going to be a large air space with no fuel. The tank is a 150. That allows for a percentage of expansion room. I don't go crazy tilting, I did the first time and it took 30 extra gallons, probably putting me closer to 160, (I had run out and got approx 30 gal) I tilt down on pass side or up on drivers, not both. By all calculations since, I am filling close to 150. That is including the extra 20 or so the tilt adds. Putting 150 gallons in a 150 tank is a no brainer, it was designed to hold that and be legal. 

[isptbart]

OK-RVR - I also always try to fill from the high side, because you can't get a full tank from the low side.  So, here is what I did to modify both of my fill nozzles & I can now get a full tank most every time. It takes a little time, but well worth it to me! Since I wanted to modify both fill nozzles I made purchases in order to have enough pieces for two assemblies. First, I stuffed a slightly oil soaked plug (rag on a rope) into the fill nozzle as deep as possible. Then I took my power band saw & cut off my fill nozzle about 2" from the tank itself (don't cut off your rag plug rope!). I purchased about 8" of 2"ID fuel hose & cut into 2 - 4" pieces. I purchased 2 brass 3" nipples.  I purchased a 6" brass nipple (2") & cut in half. I purchased 2 - 45 degree 2" brass fittings. I took a file & smoothed out all brass cut surface edges. I purchased 8 good quality hose clamps. Carefully remove the rag plug + pulling out all of the band saw cuttings. NOTE: I connected a heavy duty magnet to the remaining fill tank stub & it caught a few lingering shavings, but I was very careful to not let the shavings fall into the tank. Other plugging methods could also be used to catch the loose shavings.

Assembly per side: Put a 4" fuel fuel hose on the tank stub & secure with two hose clamps. Using a good quality diesel fuel compatible thread sealer & install 1 fully threaded nipple on one end of the 45 degree fitting & the other 3" cut nipple on the other end of the 45 degree fitting & tighten all securely. Put the assembly into the open end of the fuel hose putting the unthreaded piece into the hose & clamp with two hose clamps - after you rotate the assembly for the best angle for filling. Basically the unthreaded brass fitting will come close to mating up with the nipple stub on your tank with all secured with the hose clamps. On the remaining brass fitting end you just screw on your regular tank cap. I let the thread sealant set for a day for drying time. Duplicate these actions on the other side & you are ready to go to top off the tank. Works great for me & I can usually easily top off my fuel tank. However, now with the extra fuel the tank level sensor is initially confused because of basically initially over-filling in respect to the original OEM full tank setting at a lower level. Before I bought brass fittings, I did local comparisons verses online pricing & found I could order the brass fittings locally much cheaper & get them in about 3 days. Do your research & price comparisons. I spent about $60 total for the modifications of both sides of the tank. PS - Brass fittings are more expensive, but I initially tried cheaper black pipe fittings first, but they began to rust, so I changed out to the brass fittings & no more potential rust issues.  

Bart from VA, 07 HR 42PLQ Scepter, 07 GMC 2500HD in tow

[Ivylog]

Thought I’d posted this yesterday and Yes, the 2 nozzles are in only one side/fill…a tight fit and not coming out.
X4 or is it X5 on overfilling plus been doing it for over a decade. Never had a spill until the “new” rig and haven’t since adding the saw blade. 20 extra gallons equals 1/6th fewer fuel stops and a extra 120 miles before getting fuel. I still put in 12+ hour days, it’s 1500 miles to Co and do it in 2 days… nothing I need to see again in between.  I only have to get fuel once/day at the best price having researched before leaving.

Edited December 9, 2021 by Ivylog

[Cubflyer]

10 hours ago, isptbart said:

here is what I did to modify both of my fill nozzles & I can now get a full tank most every time

Thank you Bart for finally answering the original posters question!

[ok-rver]

As the OP, I also am thankful for the pictures of your modification. Will start accumulating the parts and schedule time to get it installed. Our MH has hydraulic leveling so I could tilt using one rear jack. With a nominal 4" above the bottom of the fill nozzle, 2" of tilt reduces the air space in half with an additional 13 gal in tank. If driving more than 100 miles b4 storing, about 12 gal consumed, I would tilt and fill fuller. 

Anyone have a measurement of were the stand pipe to supply engine fuel is above the bottom of tank? A couple of inches up and you have lost 12 gal of usable capacity.   Also read were someone extended their generator tube further into the tank. A quick look at the top of my tank and I thought the tubes were welded in place. Wonder if I missed something. 

Max amount of fuel we have pumped into tank has been around 60 gal. I had tried to start generator at this level and it started but did not continue running. It was early after we purchased the MH  and I thought fuel level was below generator  pipe. Now I prime b4 starting as the generator starts and runs better. Not sure if this would have allowed it to run. I would like to know at what full level the generator actually starts sucking air.