Fuel tank stopped venting????

[GRoutzahn]

So, I just relocated from St. Louis to Colorado. I drove the moving truck and my fiancee drove my CTD truck while pulling my tool trailer. She reports that there was no problems the entire trip however, when we got to Fort Collins (~5200 ft) I went to fill up and I noticed that for a few seconds the truck seemed to be idling rough when put it in park but then cleared up. When I went to dump the fuel in, I could hear a gurgling noise and then about a quart of fuel would puke back up the filler neck, all over the ground. This happened one more time and finally I had to spend 10 minutes filling the tank as slow as possible.



I then drive up to Estes Park (~8000 ft) w/ the last 1. 5 miles being up a 12% grade driveway. When I put it in park to let the EGTs cool down, she started idling very rough. I finally shut her down and when I opened the fuel cap there was a huge sucking noise.



So, the next morning I disconnected the filler tube and vent hose (neither were collapsed or kinked) and blew compressed air through both. The first few times I could see the tank expand under pressure and diesel would come out the filler tube but then it began venting like normal. I've driven a few hundred miles since then and the problem hasn't resurfaced.



Any ideas?



Also, the fuel sending unit on my Commander has been on the fritz and not reading so I have no info on the fuel pressure.



Sorry it's a little lengthy but thanks for any help.

 

[steved]

I think I remember reading there is a check ball in the vent hose connection at the tank??

 

[MickeyMiller]

GRoutzahn,



You are a prime candidate for Spooled-up's vent kit! You'll eliminate any re-occurance of your issue, pick up 2 - 4 more gallons of useable fuel capacity and speed up your re-fueling time!

 

[DerekW]

you could go with glacier diesel vent kit. they are nice i have one on the one truck and as soon as i recieve my replacement credit card im gonna order another for the other truck.



I once owned a rebuilt truck that had that fueling issue. it was a 04 s-10 pickup. took it back 2 days later. i remember trying to put $10 in the tank. took 10 minutes and had me upset cuz i had better things to do. normally the pumps are to slow this time it was the truck that couldnt handle the gpm. so i feel your pain.





Oh and btw you dont need to take your truck to a shop and even jack the truck up to get the fuel tank out for install. I have dropped tanks out of qc short bed and qc long bed rams on the ground and slid them right out from under the frame rails. just make sure they close to empty or your a big boy or have good jack. watch out for the sheet metal sheild that protects the tank in the event of driveline failure it is very sharp.

 

[GRoutzahn]

Haha. I knew I'd forget one important piece of info. So, I did the fuel tank vent mod (can't remember who's kit) at the end of last summer. Sorry about that and thanks for the replies.

 

[Spooled-up]

GRoutzahn,



Sounds like your fuel tank isn't venting like you suggested. No matter who's vent kit you have, they both do the same thing. They just re-locate the vent to the higher part of the tank. The vent runs up to the fill neck and enters just below the fill neck about 2" below the cap. Air has to enter the tank somewhere and I think it is done at the fuel cap and at the hose barbs that so many people have trouble with. It's unlikely that they have both clogged, which makes me suspect your fuel cap. I'm not exactly sure how it vents through the cap, but it might be worth a try to replace it and see what happens.



Someone correct me if I'm wrong that the tank is vented through the cap.

 

[steved]

GRoutzahn,



Sounds like your fuel tank isn't venting like you suggested. No matter who's vent kit you have, they both do the same thing. They just re-locate the vent to the higher part of the tank. The vent runs up to the fill neck and enters just below the fill neck about 2" below the cap. Air has to enter the tank somewhere and I think it is done at the fuel cap and at the hose barbs that so many people have trouble with. It's unlikely that they have both clogged, which makes me suspect your fuel cap. I'm not exactly sure how it vents through the cap, but it might be worth a try to replace it and see what happens.



Someone correct me if I'm wrong that the tank is vented through the cap.

It is also vented through the rollover valves... at least mine is.



I was wondering, since it is affecting it occasionally, whether something like a foil top from a bottle has gotten into the tank?

 

[GRoutzahn]

I thought it vented through the cap as well. What are the rollover valves? Is there a way to check them?



The foil top is a good suggestion. I was trying to think of any kind of obstruction that could have gotten in there.

 

[steved]

I thought it vented through the cap as well. What are the rollover valves? Is there a way to check them?

The foil top is a good suggestion. I was trying to think of any kind of obstruction that could have gotten in there.

I checked mine when I placed tubing on them to prevent getting water in the tank. There are two of them: one fore, one aft. Depending on whether you had the recall done, you might have two short pieces of tubing just hanging over the side of the tank.

After I installed the 1/4" tubing, I simple blew and sucked through it... the rollover valves don't hold pressure or vacuum.


The foil caused a friend of mine a ton of headaches... he had removed the filter sock from a pickup tube in an older dodge truck. As he drove around, the foil would suck over the end of the pickup tube... effectively shutting off the fuel. After it sat, it would bleed vacuum off and the foil would "float away", the truck would then run.

 

[GRoutzahn]

I checked mine when I placed tubing on them to prevent getting water in the tank. There are two of them: one fore, one aft. Depending on whether you had the recall done, you might have two short pieces of tubing just hanging over the side of the tank.



After I installed the 1/4" tubing, I simple blew and sucked through it... the rollover valves don't hold pressure or vacuum.





The foil caused a friend of mine a ton of headaches... he had removed the filter sock from a pickup tube in an older dodge truck. As he drove around, the foil would suck over the end of the pickup tube... effectively shutting off the fuel. After it sat, it would bleed vacuum off and the foil would "float away", the truck would then run.

I'll go out and check mine today. Thanks again for the help.