I solved the slow fillup problem on my '03

[Brian-NX9O]

Thank you!

Spooled-up - Thank you for doing this work and posting the details. I had been wondering if the rear fitting could be used to veant that space, but your solution takes it to the next level.



One question though: After pulling and examining the tank assembly, is there any reason to continue venting the original vent tube? In other words, why not just cap off the original vent fitting at the top outside of the tank and connect a new vent to rear like you did?

 

[GCrowell]

Spooled-up

Thanks for taking the lead in fixing this annoying problem. I am interested and I'm sure my brother-in-law will be also.



Just a thought... if there is concern about not leaving any expansion space in the top of the tank, one could place the new vent on the rounded portion of the upper tank rather than on the flat top. Or maybe leaving the bulkhead fitting long instead of cutting it off. I could see this providing maybe an inch of free air space while still making the fill painless.



What is the white thread sealing I see on the new vent tee?



I have not looked at the tank mounting but is it a difficult R/R? Any special precautions such as weird fittings requiring weird tools or frame/body parts in the way etc?



Thanks again!



George

 

[Jeremiah]

A huge issue

You guys make sure you read the owner's manual about what can happen when you run your tank dry. Trust me, you don't want to do this! Better to fill up before the DTE hits zero. It's not the same as a gasser where you add fuel, crank 'er up and go.

 

[Spooled-up]

EEngel

When will you be selling this "fix" in a package form?

I have had a few guys interested in a kit. I'm going to work on putting all the parts together this week. I'm going to have to hunt around for a supplier of the bulkhead fitting as they seem kind of hard to find. I have already e-mailed the manufacturer to see if I can buy direct.

 

[bpenrod]

My 99 ran out of fuel a few times and it can be a long time getting it re-started! I once put 10 gallons in and was on the side of the road for a few hours priming it (had no tools). At that time the DTE showed 68 miles!

 

[Spooled-up]

Brian

After pulling and examining the tank assembly, is there any reason to continue venting the original vent tube? In other words, why not just cap off the original vent fitting at the top outside of the tank and connect a new vent to rear like you did?

The only fitting I could find that had an o-ring and threads and a nut is made with 1/4" NPT threads coming out the top of the fitting. This makes it possible to easily connect a 3/8" fuel hose to a barb connected to this fitting. This is sufficient to vent the smaller air space, but with the factory using 3/4" i. d. fuel hose as a vent, I'd be afraid it wouldn't be enough. We might have problems with the pumps clicking off as the tank is filled. I think with the right fittings what you propose would easily work. I spent hours finding just this part though.



My '99 filled right to the top without any problems. I can't imagine that there were any air pockets left in that tank. DC just didn't want to pay to vent the tank in the proper spot in my opinion.

 

[Spooled-up]

GCrowell

What is the white thread sealing I see on the new vent tee?

I used teflon tape on all the threads. I'll include a roll in the kit because I couldn't find my roll and had to make another of four trips to the store.

 

[Spooled-up]

BPenrod,

My 99 ran out of fuel a few times and it can be a long time getting it re-started! I once put 10 gallons in and was on the side of the road for a few hours priming it (had no tools). At that time the DTE showed 68 miles!

This is how I understand how this works:





The new Common Rail injection eliminates this problem as the injectors are now electrically fired.



On the earlier 24v trucks the injectors opened when a pulse of fuel was pushed past the spring tension of the injector. If there is air in the system, it would absorb the pulse and the spring force could not be overcome. The injector would not let any fuel or air out and now you have to bleed the injectors.



On the common rail system, we don't use the fuel pulse from the pump to open the injector. A common rail is under constant pressure and the injectors are electronically fired so they don't care if there is air in the lines or not. They open when commanded. Because of this, they bleed any air off automatically.



No need to prime our fuel injection system!



If anyone knows better than I please chime in.

 

[Spooled-up]

I have not looked at the tank mounting but is it a difficult R/R? Any special precautions such as weird fittings requiring weird tools or frame/body parts in the way etc?

The forward tank strap mounting bolt was a pain to get to. I actually had to put a ratcheting closed end wrench through the mounting plate for the driveshaft support and move the nut 1-2 clicks at a time. Once you back it off about 1/4", you can get a 15mm deep socket on it with a universal joint. I don't think I could have done this without the ratcheting closed end wrench. If crawl under the truck you'll see exactly what I'm talking about.



There are 2 fuel fittings on the top of the tank that connect to the sender/pickup unit. They are quick disconnect and were easy to remove once you lowered the tank about 4". There is one electrical connector also whrere you slide a red locking tab to one side and the connector slides off when you push the clip.



I used an 11/16th hole saw to drill the hole in the tank. That was another trip to the hardware store.

 

[Jeremiah]

Running it dry

If I was going to chance running a diesel engine dry I'd carry an extra can of fuel to throw in at the first "hiccup. " The boards are full of people who can testify to what happens when air is pulled into the system. Not good unless you've got plenty of time and tools to fool around trying to get it started again. Forewarned is forearmed or something like that. 'Nuff said.

 

[klenger]

This thread is interesting to read because there are two seperate topics going on at the same time. Not complaining, just commenting. Now, back to our regularly scheduled program(s).

 

[rweis]

I got one of those 22 gallon tanks from Summit and mounted it in the bed. Use that as my aux tank. I dump the 22 gallons into the main.



The thread is about slow filling, I fill the main till it starts "balking" then fill the aux at full flow rates. Run the main, dump the aux.



Main takes about 24 gallons at the "low fuel gong" , aux has 22 gallons. I KNOW the main will take ALL of the aux when I flip on the aux. 46 gallons is about all the time my "butt" can take in one sitting.



Bob Weis

 

[HOBrian]

spooled-up I would love a parts list or a complete kit...

 

[Spooled-up]

I'm working on a kit for this. I have to find all of the parts and assemble them. If you're interested, send me a PM so I can get an idea of how many kits to make. I have 1 interested so far that has pm'ed me.



Once I get a kit together, I'll be able to pm prices back to you.



I'll probably put an ad in the TDR classifieds - basement enterprises also.

 

[catoiler]

If memory serves me right,It is 10% for expansion by law. And yes it does expand that much. The mixer drivers at work fill the tanks to the top and after a few hours in the sun they are leaking on the ground!Nice idea for the vent!

 

[John - K5AWO]

Spooled-up



One neat article... . I too try to top off for the extra miles between stops. My son had his tank down last week to fix the sending unit and I noticed that big "air hump" on it.



I commented to him that we ought to move the vent line from stock location to the top of that hump. I am cheap though, I just punched a hole and JB welded the fitting in place.



Did the same thing to my '74 Suburban tank when it needed a water drain valve. Punched a hole in the right front lower corner, stuck it in with JB weld. Waited 24 hours and filled it with "hi test" drip gas. It is called drip because it is condensate from the natural gas pipeline where I worked then. Owned that truck 17 years and it never leaked.



Water in gas? Yep, if it is condensate sourced. Don't have any sources anymore. Feds frown on using that stuff. Can't imagine why, I liked the price of it. zero

 

[MLee]

new vent

spooled-up;

sounds like this should work with all the models of trucks. but was looking at the pictures you posted, and was wondering if the little barbs on both ends could maybe replaced? for larger ones. could you tell if these barbs were one way vent? perhaps a 1/16-1/8" ID. looks like a worth while idea/job

good job.

Marv.

 

[Spooled-up]

was wondering if the little barbs on both ends could maybe replaced? for larger ones.

These little barbs on the top of the tank were not threaded in, but looked like they were part of the tank. I tried to blow into one and nothing went through it. If it does vent, it must do it out of the tank only, and I would suspect it does it very slowly if at all. Not really sure.

 

[CBrittan]

I own and operate a highway tractor and my saddle tanks are designed to be filled only to 80% of capacity. If I am very patient, I too can overfill the tanks to max.



It is my impression that all diesel fuel tanks are designed so as to discourage/prevent filling over 80% of capacity.



I would not be surprised to learn that the design of the RAM tank is intentional, and the unvented portion might just be the 20% intended to allow for expansion.



This 20% expansion space is almost certainly a legal requirement.

 

[Spooled-up]

Cbrittan,

The reason I did this mod is that I was tired of waiting. I realize that this takes away any air expansion space that may be required. I have filled my tank to the fill neck for a whole year now without any problems, leaks, etc. I did the same thing to my '99 without any problems. I haven't changed how much I fill my tank, just how long it takes to fill it. I was willing accept any problems associated with this mod on my truck. I took the chance to see if it would work and it was just as I expected.



I would bet that you are right about the design being intentional.