Improved fuel tank vent kit.

[JVolkmann]

Did I miss somehing? What exactly is wrong with the original vent kit. I installed it and have not had any problems.

 

[RKerner]

Weight conscious vent kit

Did I miss somehing? What exactly is wrong with the original vent kit. I installed it and have not had any problems.

The old one is heavy with the brass fittings and such, the new one is for the weight conscious bombers.

 

[JVolkmann]

So that is why my truck feels slower. :-laf

Ok, what is the real reason?

 

[Buzzer]

Did I miss somehing? What exactly is wrong with the original vent kit. I installed it and have not had any problems.

Nothing is wrong. Dave is eliminating the stock vent and only venting from the high point of the tank with a 3/4 inch hose eliminating the Tee as well. Also changed is the fitting at the tank.

 

[Matt400]

one of the cautions Dave makes is that you DON't want to fill the tank and let the truck sit in the hot sun... with a FULL tank!

I don't remember that caution but do remember this post:

I don't think thermal expansion is an issue and here is why,



For an example if you have 37 gal. topped up at an average underground supply tank temperature of 55 deg. and parked the truck immediately- like around the corner after filling in the hot summer heat of say 95 deg you have a temp change of 40 deg. that will expand those 37 to 37. 75 gal. if you let the truck set there long enough.



I found that info from Chevron here at the bottom of the page

3/4 of a gallon can easily bulge the plastic tank and not cause any trouble but even so, how many are going to refill that way? And remember 95 deg. is a pretty extreme number because the tank is not in the sun and is shaded by the truck.



The factor I used to find that is . 00046 x 40 = . 02 change per gallon

. 02 x 37 = 3/4 gallon



The hump in these tanks could be an expansion zone required for safety should the truck get smashed in an accident, leaving the fueling station with a full tank it would be less prone to burst as you cant compress liquid.



Or it may be there to facilitate fuel vapor purging/re-burn on gas rigs as they have an enhanced evaporative system and DC just put the same tank on the diesels that don't require that function.



Or maybe DC just goofed and didn't put the vent hose at the highest point.



Who knows maybe some day we will find out and I would be extremely surprised if it was for thermal expansion

 

[Doubleclutch]

Matt- Good refference article! I never saw a value for thermal expansion but 1. 037 for an 80*F rise is pretty minor. The new instructions from Spooled-up has the caution about filling the tank to the cap and then parking it in the sun. Maybe Dave got a talking to by his lawyer. Thanks for the hard numbers. Sure makes a "correction" a lot easier to believe.

Greg

 

[Spooled-up]

It also looks like you have gone to a gasket vs an "O" ring at the bulkhead if I read your pics correctly.

I found a bulkhead fitting and gasket in a material that is resistant to diesel fuel. You're correct that it now has a big thick gasket instead of an "O" ring.

What exactly is wrong with the original vent kit. I installed it and have not had any problems.

Nothing wrong with the old kit. I've eliminated a step in the installation, and the install is a little cleaner. You do have to put a bigger hole in the tank though!

one of the cautions Dave makes is that you DON't want to fill the tank and let the truck sit in the hot sun... with a FULL tank!

I used to include a disclaimer that I asked to be signed and returned to me. I'm not sure if it would actually cover me if someone sued me, but most people returned them. I now put this disclaimer at the top of the instructions mostly to let you know that this COULD happen if all the conditions are right. I've personally never seen it happen, and I had been filling my tank to the fill neck for a whole year before I installed the kit. What this kit will do is let you fill the tank the same way you've been filling it the very slow way, but now it takes much less time. There's bound to be someone that fills up in Arizona on a 115 degree day, tops off, and parks the truck in the sun after driving only 20 feet. They go in to eat for an hour and the fuel that was underground for days at 59 degrees is now in the desert sun for an hour. It's going to expand a little.



Here's the disclaimer included in the instructions:



Please read before installing:

This modification allows you to use the air space designed into the tank to allow for fuel expansion. If you fill your truck with fuel until you can see fuel in the filler neck on a hot summer day and then park your truck in the sun, there will be no place for the expanding fuel to go. This may cause fuel to leak. Use common sense when you fill your truck to the fill neck. This modification will probably void the warranty on your fuel tank. This modification has not been crash tested. If you have any doubts about whether you should attempt this installation and drill a hole in your fuel tank, I will refund the purchase price of the kit when the kit is returned to me minus the shipping. If you decide to sell the truck in the future, please inform the new owner about this modification so they know about the need for fuel to expand during hot temperatures. Make this modification at your own risk.

 

[Matt400]

I never saw a value for thermal expansion

Me neither Greg, I just got to looking before I was ganna do the mod. just to make sure.

 

[Matt400]

Matt do I need the fuel tank bomb on my 05??

danelle

Maybe so, you need to look at where the fuel tank vent hose connects on the 05's and if it is not on the highest part of the tank then doing this mod would make it possible to get another 3. 5 gallons in, making fuel mileage tests more accurate and allow another 50+ miles between fill ups.



I didn't even know that capacity was there until I took the time to keep drizzling the fuel in after the nozzle clicked off.



You wouldn't even have to risk driving the truck real low on fuel before taking the tank out... just siphon off the fuel to Brandon's Tool Truck, he would like that!

 

[JVolkmann]

Thanks for the reply. I was concerned there was a problem with the old kit. I like the look of this new kit. How many kits do you have available? How much bigger is the whole in the tank. Sorry for all the questions. I am really satisfied with the first kit, but if you took the time to improve the kit, I want it.

 

[JPereira]

Put the new kit in tonight. Took a little over 2 hours. The fuel line closer

to the electrical connection took me 1/2 and hour to get off. I almost wanted

to just yank it off. I had to walk away and take a breath. The clips push

buttons were vertical. I tried to turn it but with one hand and the

stiffness of the line made it very difficult. I really think I could have

done it under 1-1/2 hours if that one line came off as easy as the first

one.

I ran my tank for about 35 miles after DTE had hit 0. When I was done and

went out to refill I held it full throttle until it clicked off and took

about 15 seconds to top her off. I put 39. 5 gallons in. Prior to this vent

it would have taken me 10 minutes to fill the tank to the same level. Any

guess as to how much fuel I had left in tank?

What do you typically see for gallons when you refill a long bed after installing this vent kit?

The most I had ever seen before was 36 gallons. I am assuming I was not running it as low as I could of.

The main reason for this post was to say Thanks!! The kit was very

straight forward and the first fill up was a Dream!!



Thanks Again, Jeff

 

[JBlock]

Very true, and one of the cautions Dave makes is that you DON't want to fill the tank and let the truck sit in the hot sun... with a FULL tank! Am following this tread very closely since I have the kit on it's way, and have an in-bed Transfer-flo as well. This is one of those improvements that is so simple that the factory should have done it in the first place. Thanks Dave!

Greg

I suspect the factory is being conserative it their design (and Cheap), as you said "leaving some air space for temeral expansion of the fuel to avoid any tank damage due the fuel expanding in hot weather after filling the tank with ground temperature 65F fuel in 100F plus weather. It might be possible to extend the relocated vent into the tanks an inch or so and not effect the fill volume much and prove a little air space for expansion if one was in the southwest.



Just a thought.

 

[Jeremiah]

I don't think anyone has run a tank dry yet. They've pushed it, but not to the point where fuel pressure began falling. Personally, I wouldn't do it without a fuel pressure gauge, and then I'd make sure I had a 5-gallon can of diesel fuel in the bed.



I used to fly with a feller in a Twin Beech (D-18 to some) who knew his engines so well he could point to fuel pressure gauges at the precise moment they began faltering. Then he'd calmly reach down and switch to the auxilliary tank. That's the way to maximize range.



Unfortunately, there aren't that many drivers willing to learn rate: how many gallons of fuel a vehicle burns per (fill in the blank) hour, mile, whatever. Or precisely how many miles per gallon will the engine deliver under various power settings, load, headwind, etc. Not always easy to figure, but it can be done.



How many drivers, when asked how many miles per gallon they get, say something like, "Oh, somewhere between 15 and 17. " Or better yet: "I drive my truck two weeks on one tank of fuel!" Well, duh!

 

[Spooled-up]

It might be possible to extend the relocated vent into the tanks an inch or so and not effect the fill volume much and prove a little air space for expansion if one was in the southwest.

The Kit has a bulkhead fitting that can be mounted two different ways. One extends down into the tank and the other extend further out of the tank. Here's a pic of the 2 different ways to mount the fitting.



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[LesStallings]

Kit Arrived

My kit arrived yesterday.



Good quality stuff! I hope to get some time this weekend to get it installed.



THANKS!

 

[RKerner]

On the expansion note, also understand that the 7 layer blow-molded polyethlyene/polypropylene tanks expand at a similar rate, albeit a tad slower. (go to matweb.com and look up stuff like Huntsman polyethylene variations and their expansion rates. ) That provides expansion room during the temp gradient experience. The mounting straps also expand a tad, so all in all, the awareness of fuel expansion after a fill is good but the likelyhood of an incident is fairly remote.

 

[Spooled-up]

Thread sealer...

I had a request from someone who bought the kit about specifically what thread sealer to use. I called Permatex today and they said their High Performance Thread Sealer is fine for use with Diesel fuel, but that it is aggressive with plastics. I told him about my nylon fittings, and he said nylon was different, and that he would have to check and get back to me about the compatability.



I found a thread sealer at a plumbing supply store called Jomar Tef Seal. I called them and they confirmed that it was safe for use with nylon. It lists diesel fuel on the can. They can be reached at 248-585-5260 and can tell you where to buy it in your area. I'll post here when I hear from the guy from Permatex.

 

[Spooled-up]

I heard back from Permatex today. This is in the new instructions:



-- Thread sealer compatible with diesel fuel and nylon fittings. One suggestion is Permatex Thread Sealer With Teflon. This is readily available under the generic part number 80631 for a 1oz. tube, or 80632 for a 4oz. can. Automotive stores will use part number 14AR or 14H. NAPA will have it under part number 7651187 or 7651188. Permatex High Performance Thread Sealer is NOT recommended because it will attack the nylon. It uses an anaerobic base that is not compatible with nylon or plastic fittings. Teflon tape is not recommended unless it specifically states it’s for use with diesel fuel. Jomar Tef Seal is the sealant I found in a plumbing supply store and is compatible with both. Jomar’s phone number is 248-585-5260, and they can help find a distributor in your area.

 

[JVolkmann]

Dave, thanks for the info. You said the hole has to be made bigger. What size hole saw did you use this time? Also, How many kits do you have available? Sorry for all the questions. I want to order one, but won't be doing the install any time soon due to the cold temp.



Jeff

 

[Spooled-up]

The hole saw need is a 1 and 3/8ths.

Right now, I'm waiting on a couple parts for the kits that were on backorder. I'm hoping to ship this friday the 14th. I'll have 25 ready to go, and 4 are spoken for so far.