Fuel Tank Vent Valve?
Fuel Tank Vent Valve?
My fuel tank vent valve is not working correctly. It remains open all the time and as a result the car smells like gasoline
The valve is GM Part No. 10033125 but has been discontinued. It's the plastic valve that is located on the rear axle on the driver's side of the car. It has a tab to clip into a mount on the axle.
Does anyone have one of these used or know a supply source? Thanks much!
The valve is GM Part No. 10033125 but has been discontinued. It's the plastic valve that is located on the rear axle on the driver's side of the car. It has a tab to clip into a mount on the axle. Does anyone have one of these used or know a supply source? Thanks much!
On Probation


Joined: Apr 2007
Posts: 1,592
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From: Syracuse NY
Car: 84 Z-28
Engine: 305 HO
Transmission: r-700
Axle/Gears: 3:73
Re: Fuel Tank Vent Valve?
I would send a e-mail to denny at www.thirdgenranch.com
He may have a used one.
I see on e-bay that there are several other 0ne line connection fuel tank vent valves
One is for a blazer and is a GM part and another is a Dorman product.
You could prob. rig one of these up and attach it to the car body instead of
the axle.
Check with Denny first if you want OEM.
He may have a used one.
I see on e-bay that there are several other 0ne line connection fuel tank vent valves
One is for a blazer and is a GM part and another is a Dorman product.
You could prob. rig one of these up and attach it to the car body instead of
the axle.
Check with Denny first if you want OEM.
Last edited by sonjaab; Apr 24, 2012 at 10:21 PM.
Re: Fuel Tank Vent Valve?
Thanks guys. I was able to scare one up from henryd3, who rocks, along with an HVAC control valve -- two important parts that GM decided to discontinue. I'm going to watch ebay and stockpile a couple of these parts!
As to the vented cap, sounds straightforward. But will that work, or just vent fuel vapors into the air just like my now two-way fuel tank vent valve does? That's what I'd be concerned with.
As to the vented cap, sounds straightforward. But will that work, or just vent fuel vapors into the air just like my now two-way fuel tank vent valve does? That's what I'd be concerned with.
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From: Everett, WA
Car: 87' IROC
Engine: L98
Transmission: T56
Re: Fuel Tank Vent Valve?
Thanks guys. I was able to scare one up from henryd3, who rocks, along with an HVAC control valve -- two important parts that GM decided to discontinue. I'm going to watch ebay and stockpile a couple of these parts!
As to the vented cap, sounds straightforward. But will that work, or just vent fuel vapors into the air just like my now two-way fuel tank vent valve does? That's what I'd be concerned with.
As to the vented cap, sounds straightforward. But will that work, or just vent fuel vapors into the air just like my now two-way fuel tank vent valve does? That's what I'd be concerned with.
Last edited by 87350IROC; Apr 26, 2012 at 12:47 PM.
Re: Fuel Tank Vent Valve?
Absolutely terrible. A car that reeks of gasoline does not inspire a lot of confidence (thank God I don't smoke, LOL!). I'm suprised GM would discontinue a key and relatively inexpensive part like this. If these were '69 Camaro's these would be available next to the potato chips at Jimmy Johns. I guess GM doesn't really consider the third gens worth saving. Probably a summary of GM's attitude towards their products made after 1980 or so.
Joined: Aug 2002
Posts: 525
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From: United Kingdom
Car: 1989 TTA
Engine: 3.8L Turbo V6 - VIN 7
Transmission: 200R4
Re: Fuel Tank Vent Valve?
Anyone know if the vent valve for the 4th Gen is the same PSI rating and will work as a replacement ... got two really nice used ones (4th Gen) hence my question as the one for the 3rd Gen's been discontinued and used ones always break when removed as the plastic is so brittle after all these years on the cars ...
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From: Austin, Tx
Car: 92 Formula
Engine: L98
Transmission: A4
Re: Fuel Tank Vent Valve?
Bringing this thread back from the dead! Has anyone come up with any good sources for these things? (I've yet to find one...)
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From: NORTH EAST OHIO
Car: 89 FORMULA N10/MM5/GM3
Engine: 305 TPI
Transmission: T-5
Axle/Gears: 3.45
Re: Fuel Tank Vent Valve?
I had the fuel smell with mine also.
Has any one thought about disassebling the valve cleaning it and putting it back together.
That is what I did with mine and it worked like a charm. Just sayin.
Alot of dirt and crud in there, probably due to the location near the rear wheel.
Has any one thought about disassebling the valve cleaning it and putting it back together.
That is what I did with mine and it worked like a charm. Just sayin.
Alot of dirt and crud in there, probably due to the location near the rear wheel.
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From: MICHIGAN
Car: 1988 Trans Am
Engine: L03
Transmission: 700R4
Axle/Gears: 10 Bolt 2.73 Open
Re: Fuel Tank Vent Valve?
I had the fuel smell with mine also.
Has any one thought about disassebling the valve cleaning it and putting it back together.
That is what I did with mine and it worked like a charm. Just sayin.
Alot of dirt and crud in there, probably due to the location near the rear wheel.
Has any one thought about disassebling the valve cleaning it and putting it back together.
That is what I did with mine and it worked like a charm. Just sayin.
Alot of dirt and crud in there, probably due to the location near the rear wheel.
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From: NORTH EAST OHIO
Car: 89 FORMULA N10/MM5/GM3
Engine: 305 TPI
Transmission: T-5
Axle/Gears: 3.45
Here is an old one from my spare parts bin. I will disassemble and clean it tomorrow morning, post some pics with a detailed procedure. Should be a help to everyone here.
Joined: Aug 2013
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From: MICHIGAN
Car: 1988 Trans Am
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Axle/Gears: 10 Bolt 2.73 Open
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From: United Kingdom
Car: 1989 TTA
Engine: 3.8L Turbo V6 - VIN 7
Transmission: 200R4
Re: Fuel Tank Vent Valve?
Main problem with them is the plastic is so brittle ... the tabs holding it to the metal bracket break so easily and also when you do pry it open you find that some are very easy to take a part while others are really stuck together (from manufacturing when assembled) and hard to take apart without breaking one of the two halves.
If you can twist the upper and lower halves easily it should come apart fairly easy.
If you can twist the upper and lower halves easily it should come apart fairly easy.
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From: NORTH EAST OHIO
Car: 89 FORMULA N10/MM5/GM3
Engine: 305 TPI
Transmission: T-5
Axle/Gears: 3.45
I will try to be quick about this and keep it short. Besides it will 70 here in Cleveland today and I am really excited about getting my Formula washed up and out for fresh tank of gas and a long cruise.
The most important thing to remember here is not to break the plastic you have to use a pick tool to disassemble the valve, not a screwdriver!
Here is the first pic before disassembly.
The most important thing to remember here is not to break the plastic you have to use a pick tool to disassemble the valve, not a screwdriver!
Here is the first pic before disassembly.
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From: NORTH EAST OHIO
Car: 89 FORMULA N10/MM5/GM3
Engine: 305 TPI
Transmission: T-5
Axle/Gears: 3.45
While doing this gently work the tool between the two valve body pieces and add some pressure to pull the help pull and separate the two halves apart. Note only one tab need to be released, not all six. If you do break or deform one it is not a big deal. When reassembled the unit will function fine and stay together.
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Joined: Nov 2012
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From: NORTH EAST OHIO
Car: 89 FORMULA N10/MM5/GM3
Engine: 305 TPI
Transmission: T-5
Axle/Gears: 3.45
Next clean and degrease all parts. I would recommend super clean and soapy water rather than carb or brake cleaner, both to harsh for the plastic and rubber parts inside.
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Joined: Nov 2012
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From: NORTH EAST OHIO
Car: 89 FORMULA N10/MM5/GM3
Engine: 305 TPI
Transmission: T-5
Axle/Gears: 3.45
Finally reassemble the pieces and snap together and you are good to go.
Hope this helps some members out, sorry about the poor pic quality I used my Iphone to post this.
Now if you will excuse me I have a Third gen in the garage that needs some exercising. Can't wait to pull the gears! Worst winter here in 30yrs.
Have a good weekend every one.
Hope this helps some members out, sorry about the poor pic quality I used my Iphone to post this.
Now if you will excuse me I have a Third gen in the garage that needs some exercising. Can't wait to pull the gears! Worst winter here in 30yrs.
Have a good weekend every one.
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From: MICHIGAN
Car: 1988 Trans Am
Engine: L03
Transmission: 700R4
Axle/Gears: 10 Bolt 2.73 Open
Re: Fuel Tank Vent Valve?
Outstanding! Thank you sir. All copied, captioned, and saved to my hard drive.
From a Metro Detroiter to a N.E. Ohioan, I hope you enjoyed your drive. It's nice to see winter finally over.
From a Metro Detroiter to a N.E. Ohioan, I hope you enjoyed your drive. It's nice to see winter finally over.
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Joined: Aug 2003
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From: Crest Hill, IL
Car: 1989 GTA Trans sold :(
Engine: 350 TPI L98 (B2L)
Transmission: TH700 R-4
Axle/Gears: 3.27
Re: Fuel Tank Vent Valve?
Finally reassemble the pieces and snap together and you are good to go.
Hope this helps some members out, sorry about the poor pic quality I used my Iphone to post this.
Now if you will excuse me I have a Third gen in the garage that needs some exercising. Can't wait to pull the gears! Worst winter here in 30yrs.
Have a good weekend every one.
Hope this helps some members out, sorry about the poor pic quality I used my Iphone to post this.
Now if you will excuse me I have a Third gen in the garage that needs some exercising. Can't wait to pull the gears! Worst winter here in 30yrs.
Have a good weekend every one.
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Joined: Jan 2014
Posts: 25
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From: Cleveland, OH
Car: '89 GTA
Engine: 383
Transmission: T5
Re: Fuel Tank Vent Valve?
Finally reassemble the pieces and snap together and you are good to go.
Hope this helps some members out, sorry about the poor pic quality I used my Iphone to post this.
Now if you will excuse me I have a Third gen in the garage that needs some exercising. Can't wait to pull the gears! Worst winter here in 30yrs.
Have a good weekend every one.
Hope this helps some members out, sorry about the poor pic quality I used my Iphone to post this.
Now if you will excuse me I have a Third gen in the garage that needs some exercising. Can't wait to pull the gears! Worst winter here in 30yrs.
Have a good weekend every one.
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From: NYC
Car: 1982 Recaro TA, 1989 TTA#948
Re: Fuel Tank Vent Valve?
Make sure your vent is plumbed properly.
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From: Summerville, South Carolina
Car: 1987 Camaro Sport Coupe
Engine: 305 (LG4)
Transmission: 700R4
Re: Fuel Tank Vent Valve?
The last time I dropped the tank was in 2003. My current problem didn't show up till 2011. I sold the car to a friend in 2008, and he drove it for a couple of years then the car sat for a year in a field. Got moved around every blue moon, but for the most part it just sat. I bought it back, and at first it wouldn't vent at all when filling up. Tried cleaning the vent and now it vents so well it dumps gas on the ground every fill up.
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From: NYC
Car: 1982 Recaro TA, 1989 TTA#948
Re: Fuel Tank Vent Valve?
The last time I dropped the tank was in 2003. My current problem didn't show up till 2011. I sold the car to a friend in 2008, and he drove it for a couple of years then the car sat for a year in a field. Got moved around every blue moon, but for the most part it just sat. I bought it back, and at first it wouldn't vent at all when filling up. Tried cleaning the vent and now it vents so well it dumps gas on the ground every fill up.
Last edited by 82tarecaro; May 2, 2014 at 07:54 AM.
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From: Baldwinsville, NY
Car: 89 Iroc-z Convertible
Engine: LB-9 305 TPI
Transmission: 5 Speed
Axle/Gears: Posi 3.08
Re: Fuel Tank Vent Valve?
Thanks for the info on cleaning the valve. I work in the parts business and cannot locate a new anywhere. I'll have to give it a try.
Re: Fuel Tank Vent Valve?
My 92 recently failed smog in CA because my tank would not hold pressure when tested. It always did in the past and it had the recall work done on the fuel filler neck issue back in the day.
Could this be causing it? I've never even heard of it before. Anyone know the GM P/N for this valve?
Could this be causing it? I've never even heard of it before. Anyone know the GM P/N for this valve?
Last edited by 92GTA; May 7, 2014 at 01:17 PM.
Re: Fuel Tank Vent Valve?
Yeah and they are always changing it too! The past couple tests, they don't even manually verify the EGR function anymore and this last time they added the pressurize the tank thing. Before they would just test the gas cap seal on a machine.
My engine emissions passed with flying colors clean as could be, but I failed just for my tank releasing pressure too quickly. Freakin a.
My engine emissions passed with flying colors clean as could be, but I failed just for my tank releasing pressure too quickly. Freakin a.
Joined: Sep 2000
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From: Moorpark, CA
Car: '91 GTA, '92 T/A Convertible
Engine: GTA: 350 w/Vortec heads, T/A: 305
Transmission: Pro-built 700R4
Axle/Gears: GTA: 3.27, T/A: 2.73
Re: Fuel Tank Vent Valve?
That sucks Alex. When did they add the tank pressure test? Seems like they're trying to invent ways to get our cars off the road.
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From: CT
Car: 1984 Chevrolet Camaro Z28
Engine: 5.0 Liter 4-BBL V8 High Output
Transmission: 5-Speed Manual
Axle/Gears: 3.73
Re: Fuel Tank Vent Valve?
I keep my car registered at a friends address up in the mountains where it's a different smog "zone" from Bakersfield so it's just a tail pipe test and not on a dyno. Surprises me how even the most basic type of test is so rigorous now.
Joined: Mar 2002
Posts: 854
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From: Rincon, Ga.
Car: 91 Camaro RS
Engine: 305 TPI conversion.
Transmission: T56
Axle/Gears: 3.73 posi 4th gen rear
Re: Fuel Tank Vent Valve?
I have a tank ventire valve I took apart and cleaned. Ready to install. $15 plus shipping. Pm me for pictures
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Car: '89 Iroc Z28-15,100 Original Miles
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From: Connecticut
Car: 86 IROC w/Danko bodykit, 1988 iroc vert, 1989 k1500 pickup 6" lift and 35" tires, 2002 chevy tahoe z71
Engine: 383 stealth ram, 305 tpi, 350 tbi, 5.3l
Transmission: T56, 700r4, 700r4, 4l460
Re: Fuel Tank Vent Valve?
Quick question guys. My tank builds up alot of pressure. I have all the emission stuff deleted and went from carb to EFI. Would the vent valve stuck closed cause this issue also. I went with a vented cap and the pressure that came out started to make the pain peal on the inside of the gas tank door.
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From: North west Fl
Car: Corvette ZR-1
Engine: LT-5
Transmission: 6 sp
Re: Fuel Tank Vent Valve?
On hot days sometimes I hear a high pitch hiss and smell raw gas. The sound is coming from the area of the tank driver's side. Could this be the vent? and if so should it sound like that?
Thanks for any help,
Robin
Destin,Fl
Thanks for any help,
Robin
Destin,Fl
Joined: Apr 2000
Posts: 3,938
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From: Huntsville AL
Car: 88GTA
Engine: 5.7TPI
Transmission: Auto
Axle/Gears: 3.27
Re: Fuel Tank Vent Valve?
cmk-2 Yes, that's the little vent opening. It opens around 6-7psi. Sometimes it will sound like a dying cow. If you open the cap, the cow dies!
PS: Just got back from 10day in Destin/FWB!
PS: Just got back from 10day in Destin/FWB!
Joined: Apr 2000
Posts: 3,938
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From: Huntsville AL
Car: 88GTA
Engine: 5.7TPI
Transmission: Auto
Axle/Gears: 3.27
Supreme Member

Joined: Dec 2012
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From: northern VA
Car: 88 Sport Coupe Camaro
Engine: V6 2.8
Transmission: Borg-Warner T-5
Axle/Gears: RPO/GU6: 3.42
Re: Fuel Tank Vent Valve?
This thread helped me to make this:
https://www.youtube.com/watch?v=40cc...NB3q1&index=24
https://www.youtube.com/watch?v=40cc...NB3q1&index=24
Joined: Feb 2001
Posts: 8,494
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From: Sophia, NC
Car: 2016 Camaro SS + 1986 Z28
Re: Fuel Tank Vent Valve?
I remembered this thread from a search a few months ago. Knew the time was coming to swap the pump, and I wanted to clean that valve too. started work last night on the pump swap, searched for this thread this morning and BAM...new posts with a video!!!!! Awesome!
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From: Northern part of The Netherlands
Car: '88 Firebird Formula 350
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Re: Fuel Tank Vent Valve?
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From: Northern part of The Netherlands
Car: '88 Firebird Formula 350
Engine: 350 (5.7 TPI)
Transmission: auto 700R4
Axle/Gears: BW 9-bolt L.S.




