fuel filler cap ?

[pwr2tow]

Hi all, just wondering! when you remove your filler cap for fuel does it make a vacuam release sound or is my roll over valve stuck. Thanks, Ron

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1999, 3500, 6x6, slt, auto, 3. 54, Qd cab, ISB cummins, towing 2001 26RKSS Tahoe 5th wheel, 1999 120hp 1800 bayliner.

 

[pwr2tow]

Thanks fuzz, I heard of the red cap before and looked but did not see one, looks like i will have to check again. Ron

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1999, 3500, 6x6, slt, auto, 3. 54, Qd cab, ISB cummins, towing 2001 26RKSS Tahoe 5th wheel, 1999 120hp 1800 bayliner.

 

[LDusky]

My release of the cap has made a sucking sound for 3 yrs. How do you go about checking for the Red Cap?

 

[sdalton]

Crawl under the truck, look on TOP of the gas tank. There is the fuel sending unit on top, with some hoses coming out. There should not be any little red cap on anything coming out of the sending unit. It might not be red, if it is really dirty. The cap is approx 1/4 inch long by 1/16 inch wide. Kind of small, but can do major damage to your fuel pump if left on. It can starve the fuel pump and this can lead to premature wear.

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Y2K, 2500, 4x2, QC, 3. 54 LSD, Auto, patriot blue. K&N, silencer ring put back in. 14000 miles as of 1-05-01. best milage:28. 5 mpg. transmission reflashed

 

[Big-D]

I have a '99 and never heard a "sucking sound" from my fuel cap upon opening. I will pay a little more attention to mine next time for I am more concerned about the cost of fuel making a sucking sound from my wallet. Will let you know for in a few days if I hear anything for long trip is planned for tomorrow.
Dave

 

[Fuzz]

Ron,
Mine did that,couple dealers said it was supposed to. IT IS NOT.
Mine had the "red nipple" on the vent on top fo gas tank. When I finally got around and checking for it. Found it on there and took it off.
No more sucking sound

 

[Dave Fritz]

Here is a photo of the "red cap" location (cap removed)
<a href="http://209.15.166.145/tech/dsl/troubleshooting/d_fuel_vent10.jpg">#ad
</a> Full Sized Photo

(It almost worked the 1st time!) Dave

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1994 2500HD 4X4 modified for off-road camping
2001 2500 ETH/DEE QC SB 4X4
Fritz's Dodge Ram Tech Page

[This message has been edited by Dave Fritz (edited 01-08-2001). ]

 

[pwr2tow]

Thanks Dave, but there is no red cap on the vent tube and it still sucks air when i remove my filler cap. I inspected the filler cap and found a spring loaded plug in it and i think it was stuck, i can move it with a small screwdrive inserted into it and if i suck on the cap i can get air to pass through it now. Will be going on a 150 mile trip tonight so when i get back i will fill with fuel and see if there is still vacum in the tank, hopefully i can report back tomorrow. Regards, Ron

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1999, 3500, 6x6, slt, auto, 3. 54, Qd cab, ISB cummins, towing 2001 26RKSS Tahoe 5th wheel, 1999 120hp 1800 bayliner.

 

[LDusky]

Dave, Thanks for the picture I will look when it stops raining. Pics really help.

 

[tlippy]

Neat pic Fritz. Go to DC and buy a locking fuel cap. My OE cap left some vacuum - but the locking cap has not.

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99' Quad 4x4 A/T LB 3. 54 30K Miles.
26' Terry w/slide 7500GVWR
"KISS your truck and it will be forever faithful"

 

[Cooker]

Thanks for the pic, but I have one question. Was this port designed as a vent? It seems if we are to remove the plug then it is a way for contaminates to enter the tank, don't you think?

Maybe I'm over-reacting to something trivial?

 

[Steve]

MY 95 does this when the cap is taken off I think its building pressure in the tank. I put a small hose on the roll over valve I could suck a little air from it but could not blow any into it.

 

[Phil Stuart]

Dave,

YOU ARE THE MAN!

Good picture and a kick a** website!

Phil

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`01 2500,4x4,QC,LB,ETC,DDX,DHG
3. 55 LSD,Tow Pkg. ,Snow plow pkg. ,Forest Green PC,Mopar alum. side steps,Mopar mud flaps with Cummins logo,Mist grey seat covers,Tekonsha brake controller,Hadley air horns,Pacbrake.
Built in St. Louis
THE BIG GREEN MACHINE

Phil Stuart

 

[WCrovo]

My 99 and 2001. 5 made no sounds when removeing cap.

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2001 2500 tow, camper, SWB, ETH, Bright white.

 

[N8LHG]

Folks,

I looked at my "red cap" location on my tank, I actually have a small rubber hose which heads up towards where the fuel fill cap is located. Is the "red cap" without the hose a cost cut in newer trucks?


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Mark Wardell
1996 Dodge 3500, 4x4, Duel, Green and silver.

 

[Dave Fritz]

The vent hose disappeared some time around 1998. Since then, a large number of Ram owners have found their vent fittings capped. The photo is of a chassis cab in a dealer's lot, and the cap had already been removed. Apparently Chrysler decided to save a few pennies by deleting the hose. If you do much deep water fording, it would probably be a good idea to add the hose (and also extend the axle, transmission, and transfer case vent lines).

FWIW: An aftermarket locking cap includes a vacuum vent that works very well. The OEM cap also has a vent but, as some have noted, it does not always work well.

Dave


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1994 2500HD 4X4 modified for off-road camping
2001 2500 ETH/DEE QC SB 4X4
Fritz's Dodge Ram Tech Page

 

[Big-D]

Ron, after filling my tank 3 times on this trip I never heard a vacuum sound when removing the fuel cap. I did look under my truck('99)for the red cap and did not see one. Has anybody tried sticking a small pin in the 90 degree tube shown in the picture by Dave Fritz? Should it be open or is there a check valve just below the elbow?

 

[ralphr]

They are not all red in color. I read, no pun intended< about the infamous cap and looked could not find any "red" cap on the vent line. It would make the big sucking sound, no nafta was not making it, when I went to refuel. I checked again real close and did find a black cap on one of the lines, removed it and no more sucking sound.

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1999 3500 quad cab, auto aero fendor trim and running boards,
bugflector II, K&N filter, Geno's monster tip