Fuel Tank Leaking with gravity fed auxiallary tank

[matches]

I installed a 25 gallon auxiallary fuel tank in the bed of my truck with a RDS overflow preventer valve. The valve goes inline of the 1 1/2" fill hose and has a check valve so that the fuel cannot fill past that valve. The problem is the fill hose connects to the tank at the highest point of the tank. The tank fills and leaks out of the top of the tank, the lower part, before it can reach the check valve. Should the tank be leaking from the top? It appears to be leaking from the fuel lift pump assembly.

 

[steved]

I've been feeding mine via gravity for two years without a check valve... it doesn't leak anywhere on mine...

 

[Turbo1Ton]

Check here

See this post https://www.turbodieselregister.com/forums/3rd-generation-ram-forum-no-engine-transmission-discussions/202256-possible-fuel-tank-issue-03-04-5-trucks.html#post1948361 for a possible culprit. Mine poured fuel all over the ground as I topped it off at the station.



Jeff

 

[CKelley1]

we have had leaking problems with a lot of our pre 2000's but none after. most were in the filler vent area but a couple was on top, it needs to be fixed any way. and as stated you do not need check valve

 

[B.G. Smith]

I had the same problem with a 99 when I installed a tank in the bed. It turned out to be leaking at the fuel gage/pump module which is held in place by a big plastic nut. I got under the truck where I could see the nut and used a piece of wood (hammer handle) about 20 inches long and placed it against the ridges on the nut and tightened it some, no more leaks for six years when i sold the truck. bg

 

[matches]

That big plastic nut thing is where it looks like its leaking so I'll try to tighten it and I'll check out the other as well. Thanks for the ideas.

 

[matches]

This is the general area the leak is coming from. Should this be unplugged? What you are looking at is the fuel gage module. The thing with the hole is a grey fitting next to the infamous rubber cap. My cap was moist but didn't seem to be bad. Maybe it is cracked and I can't tell without taking it off.

 

[juicedcummins]

Mine will leak out of one of the vents when my rig has been sitting in the sun and not run. In my case it is just the expansion of the fuel.

My fuel is fed through a vane style fuel pump into the factory vent line and my aux tank has a one-way check valve on a filtered vent.

 

[JERRYKAM]

I have also been experiencing a minor amount of fuel leakage that appears to be coming from the top of the tank when it is being fed from my 50 gal gravity feed aux tank. The leakage at this point is not sufficient to motivate me to drop the tank to find the leaking seal.

 

[B.G. Smith]

The round object in the foreground of your picture with the ridges is what I tightened on mine. I dont remember mine having the dark colored thing in the background. The one I have now has a small vent on top of the tank at each end, I think that started with the 03 trucks, it is a one way vent to allow fuel to be used with out collapsing the tank. bg

 

[matches]

The one way valve makes sense. I'll keep an eye on it and see. It only leaked when the truck was sitting. I don't think I'll have a problem while I'm towing. It doesn't flow that fast. Thanks

 

[JLandry]

The one way valve makes sense. I'll keep an eye on it and see. It only leaked when the truck was sitting. I don't think I'll have a problem while I'm towing. It doesn't flow that fast. Thanks

Matches,

My main tank leaked at the rollover valve the first time I let it fill completely by gravity from an aux tank in the bed. I solved the problem by connecting a 1/4" ID fuel line to the rollover valve nipple and routed it up to a vent on the top of the aux tank. I used miniature hose clamps to secure the fuel line.

Problem solved! The main tank never leaks even when filled to the gills.

John L.

 

[matches]

Is that nipple the rollover valve? I thought about doing the same thing but I don't have a vent on my auxillary tank I was just gonna run it up higher than my check valve.

 

[steved]

That's one of the valves... there are two others located on the tank itself (not on the pickup assembly)... these should have a short piece of hose attached to them if the recall was done... if not, they will be two open nipples set into pockets on the front and rear of the top of the tank.

 

[matches]

Thanks, I found the tsb on the rov. And I will be fixing it myself. It only involved certain 2006 models, but I think it will solve my problem.

 

[steved]

Thanks, I found the tsb on the rov. And I will be fixing it myself. It only involved certain 2006 models, but I think it will solve my problem.

the other two are considered roll-over valves as well... they affect anything from 03 to 07 if I remember correctly. My 04. 5 has them...

 

[JLandry]

I thought about doing the same thing but I don't have a vent on my auxillary tank I was just gonna run it up higher than my check valve.

In theory, you need to run any main tank vent lines higher than the highest level that your aux tank could get. This is because if the filler neck check valve didn't do its job and fuel kept flowing into the main tank, ultimately fuel could creep back up the vent line but would stop once it reached the same level as the aux tank.



One option for terminating the vent line is to route and secure it up near the top of the void space between the bed wall and outer truck body. Again, anyplace where the open end of the vent line is higher than the highest fuel level in the aux tank is adequate.



John L.

 

[matches]

Well I tested the rov theory with conclusive results. I put a hose on the rov nipple and let it run below the tank and opened the valve to my auxillary tank. Soon after fuel came poring out of the end of the hose proving that's where my leak is. I beleive that if I run the hose higher than the main tank it shoudn't overflow and if anything, back up to the check valve I installed.

 

[roadking]

were do you get this valve any one have a link to the site thanks

 

[JLandry]

were do you get this valve any one have a link to the site thanks

Do you mean the rollover valve on the main tank or the check valve included in the kit to connect an in-bed aux tank to the truck's filler neck?



If the rollover valve, that's a stock part installed by Dodge in the top of the main fuel tank. Some model trucks have three rollover valves and some (my 2001 for example) only has one on top of the fuel tank module.



If you mean the filler neck kit:



Diesel Install Kit for Auxiliary Diesel Fuel Tank at Norther Tool



Best regards,



John L.