Tank fuel leak.

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Whenever I take the time while refuelling to fill the tank right to the top of the filler neck with fuel (not foam), I notice a leak of approx. 1 drop every five seconds. down the side of the tank, probably from somewhere on top. Doesn't happen if I go to nozzle shut off a few times when the fill pipe is still filled with foam. Any suggestions? Also, if fuel can leak out, can dust/dirt 'leak' into the fuel? Tank is original equipment.
Thanks.

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Ian.

'93 2wd ext. cab. Upgraded injectors, 3. 5" exhaust, K & N filter, Xmsn oil cooler and fan, 4 gauge mount, lowered and widened mirrors

 

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I'd check the rubber hose and clamps going to the tank from the filler. If this isn't the problem it may be the tank gauge set seal and the tank would have to come out. Where it snows and rains that ain't good as the snow could melt from being blown on top of the tank and leak into your fuel.
Take a few to find the leak. As you said if it leaks out it can leak in!!!
Jason


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Jason's Lil' Mack - 89 D250LE 2WD 5 Spd 3. 55 Reg Cab. K&N,"tweaked pump", 3. 5" Exst straight,E&M Custom seats. Bosch H4, PIAA 80W/80W HdLites. Bosch 100W Driving. Bosch 55W Fogs.
229,000 miles (366,000 Kms)
7550 Hrs.

 

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Ian there is a TSB (14-15-93) covering this condition. It is printed in TDR issue 14,pg. 55. When filling to the very top fuel may leak out of the vent roll-over valve. If you want to continue to fill to the very top it recommends adding a vent hose to the end of the vent nipple.
Gene
92 350 4x4

 

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Yea, same problem here. Local shop says it is one of the o-rings. I'll know more next week after it has been fixed. I also am concerned about possiblility of fuel contamination.
Doug

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91. 5 D250 5 speed, 16cm2 housing, gauges (EGT, boost, tach), BD exhaust brake (w/ 60lb springs)

 

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Thanks for the input so quick. Doug, I'd be interested to hear what your local shop found to be the problem. I don't usually fill right to the top, but interesting to check mpg. Have just done 867 km on 102. 1 litres. Presently have the canopy fitted, usually it's off so I can tow a 5th wheel.

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Ian.

'93 2wd ext. cab. Upgraded injectors, 3. 5" exhaust, K & N filter, Xmsn oil cooler and fan, 4 gauge mount, lowered and widened mirrors

 

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Due to a filling mishap I recently had to drain the tank on my truck. In order to drain the tank I had to disconnect the vent & filler hoses between the tank and the fueling spout. There are four clamps. I would also check the hoses for cracks.

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92LE,Cummins,tach,4x4,5spd,Borgeson steering shaft,

 

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Recently developed a similar problem when filling up. Mine drips when I fill up regardless of tank level... found a cracked filler hose. Plan to replace it next week-end. Good luck,
kad

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Stock '91 sc W250, 5sp, 3. 54's, 235/85's,250k+.

 

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Ian,
Just got the truck back from the shop this afternoon. They checked the roll over vent as per the TSB, but it was fine. The problem was the seal on the sending unit (part number 52018808). Hope you find your problem.
Doug

 

[Archive]

Thanks everyone for the posts, three in the first few hours.
Fitted the hose per the TSB yesterday, also evidence of leakage at the hose connection on the fill line. Slackened the clamps, moved the hose, cleaned the pipe connections and repositioned the hose, tightened the clamps again. Wrapped the hose with plastic, will collect any leakage at next refuel. Will advise results.
Thanks again.


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Ian.

'93 D250 ext. cab. Upgraded injectors, 3. 5" exhaust, K & N filter, Xmsn oil cooler and fan, 4 gauge mount, mirror tubes reversed, RACOR fuel filter, larger transmission oil pan.

 

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The leak continues. As I earlier posted, I had the o-ring replaced. Well, the shop didn't bother to reconect the filler hose to the fuel tank! Not a happy camper. Upon returning it to the shop, they have "discovered" that the plastic inlet for the return fuel line is cracked/broken. Now I'm waiting for parts #ad

I do have a question: Should the return fuel line leak when refueling or would it only leak under presure? I am becoming a bit skeptical of the local shop!
Thanks. Doug

 

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Doug,
Sorry to hear you are still leaking fuel. Seems to me if the return line is leaking, you will have a leak while the engine is running.
My leak is definately the fuel filler hose, the 2" dia. piece. Double clamped it, slowed it down, still leaks if "I fill to spill". Easiest way I've found to leak check, wrap two or three layers of plastic bag around the connection, secure with tie wraps. See what happens. Good luck.

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Ian.

'93 D250 ext. cab. Upgraded injectors, 3. 5" exhaust, K & N filter, Xmsn oil cooler and fan, 4 gauge mount, mirror tubes reversed, RACOR fuel filter, larger transmission oil pan.

 

[Archive]

Doug, don't let them charge you for that cracked return line at the tank. Thats just sloppy work on their part #ad
They should be happy to replace it since they couldn't figure out the filler hose connection!!! Try another shop if you can, I understand you are limited there.

Jason

 

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Well, just got back from holidays after a delay while the local shop replaced the entire module at their expense. Leak was still present #ad
I asked the service manager if he had checked out the TSB (thanks for that post GeneH!). Well guess what? Problem seems to be solved now #ad

Just have one question: What exactly is the purpose of this vent roll-over valve? Is it a check valve or should we be concerned about possible contamination of the fuel?
Thanks.
Doug

 

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Doug,
I believe the anti roll over vent valve is to prevewnt leakage if you drive your truck upside down.
My 92 leaked if I filled it to the very top of the neck. Had to pay and hit the road before a big mess was made.
Just fill it to the 1st auto pump shut off. It will be fine.

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1998. 5; 24v,3500,4x4,SLT,QC,5 spd,3. 54,all options available when ordered, 18k lb. Reese full tilt 5th whl. hitch, oem full length diamond plate running boards, eyebrows & hood dam, bed edges,bedhooks plus Rhinohide liner, Pacbrake, britebox,"deepdish"mats, matching topper shell, Sandstone(looks gray to me) & camel leather, stainless fender eyebrows, chrome(and road tar) exhaust turndown pipe.
brush guard, SPA digital boost/egt gauge and pillar mount.
Lowered rear end 4" to set truck level.
See My Truck

1980, W200, regular 4 door crewcab, 360 gas, auto, 68k original miles, 4 coats of Zeebart but losing ground to the saltwater anyway.