Gas Cap Pressure/Gas Smell (1 Viewer)

[SweetTNFJ80]

I have read threads concerning charcoal canister issues and other small fix’s for the smell. Also saw the aftermarket GM part that works just like OEM at much less cost. My question is “is this issue for sure fixed with a new charcoal canister, and is the gas cap suppose to be vented?” Where should I start in diagnosing this issue?

 

[rolliges]

Yes; a new canister will fix the issue AND the gas cap is vented.

(start at the front).

 

[GetNRekt]

Just replaced mine with the Duralast VC120. $40. Works great.

 

[60wag]

The gas cap is vented in that there is a one way valve to let air into the tank. It is not vented to let air out of the tank.

 

[Wompom]

If the gas cap let air OUT of the tank it would defeat the entire purpose of a charcoal canister.

 

[CaptClose]

Just replace the charcoal canister. It’s cheap and easy. Problem solved. Don’t over think it.

 

[SweetTNFJ80]

Thanks for the help. Will stop by autozone today.

 

[Mountainpassing]

i did it, it worked..simple. do it now before the summer heat and you boil yer gas.

 

[jksinton]

After changing my canister, I had a gas smell that persisted. Turns out I had a leak at the fuel filter outlet, which is below the charcoal canister. I was able to watch it drip fuel from the outlet as the engine ran with the driver side wheel off.

 

[Red Merle]

If the gas cap let air OUT of the tank it would defeat the entire purpose of a charcoal canister.

Stop blinding us with science here.

 

[rolliges]

I believe that all modern (i.e. OBD II) gas caps vent in both directions around a specific pressure range.

Just what I've read and forgotten....

 

[Dissent]

After changing my canister, I had a gas smell that persisted. Turns out I had a leak at the fuel filter outlet, which is below the charcoal canister. I was able to watch it drip fuel from the outlet as the engine ran with the driver side wheel off.

What's the fix for that issue? I replaced both the charcoal cannister (ACDelco 215-153) and put a new gas cap o-ring on and the strong fuel smell still persists. Now that I have remote start, my truck smells really strong when I approach it after a few minutes of running in park.

 

[jksinton]

What's the fix for that issue? I replaced both the charcoal cannister (ACDelco 215-153) and put a new gas cap o-ring on and the strong fuel smell still persists. Now that I have remote start, my truck smells really strong when I approach it after a few minutes of running in park.

I would try to identify the location of the leak. It's really common for the fuel tank to develop a crack on the top and leak fuel/vapors.

Check the fuel filter for a leak. Best to take the driver's side front wheel off for that.

And maybe check other fuel line connections. Are you seeing any drop marks on the ground?

I fixed the leak at the fuel filter with a new OEM filter and crush washers. And I made sure the banjo bolts we're good and tight. Don't expect to get the proper torque specs. It's too tight to fit a torque wrench in there.

There's tons of threads on how to replace the fuel filter, but this is the one I found most helpful:

Fuel Filter Replacement - Complete

Anyone have a PN on the crush washers or gaskets? Do you have to replace or can you re-use? You need (2) washers per bolt. These are the only sealing provision in the design. It's not a good idea to reuse them. Banjo bolt 90401-12097 Washer 90430-12026

forum.ih8mud.com

I ended up cutting a notch on the inner bracket of the filter. Do this! It saves you tons of time in mounting the filter.

 

[Dissent]

I would try to identify the location of the leak. It's really common for the fuel tank to develop a crack on the top and leak fuel/vapors.

Check the fuel filter for a leak. Best to take the driver's side front wheel off for that.

And maybe check other fuel line connections. Are you seeing any drop marks on the ground?

I fixed the leak at the fuel filter with a new OEM filter and crush washers. And I made sure the banjo bolts we're good and tight. Don't expect to get the proper torque specs. It's too tight to fit a torque wrench in there.

There's tons of threads on how to replace the fuel filter, but this is the one I found most helpful:

Fuel Filter Replacement - Complete

Anyone have a PN on the crush washers or gaskets? Do you have to replace or can you re-use? You need (2) washers per bolt. These are the only sealing provision in the design. It's not a good idea to reuse them. Banjo bolt 90401-12097 Washer 90430-12026

forum.ih8mud.com

I ended up cutting a notch on the inner bracket of the filter. Do this! It saves you tons of time in mounting the filter.

I'll check the filter. I haven't seen anything on the sending unit or anything obvious dripping. I'm waiting for @NLXTACY to finish that fuel filter bracket kit.

 

[rolliges]

What's the fix for that issue? I replaced both the charcoal cannister (ACDelco 215-153) and put a new gas cap o-ring on and the strong fuel smell still persists. Now that I have remote start, my truck smells really strong when I approach it after a few minutes of running in park.

It probably won't help you current issue, but I think there's more to gas cap pressure regulation than the o-ring. They're cheap, get a new one.

Do you still have tank pressure "hissing" when filling up?

 

[Dissent]

It probably won't help you current issue, but I think there's more to gas cap pressure regulation than the o-ring. They're cheap, get a new one.

Do you still have tank pressure "hissing" when filling up?

No hissing anymore, may try a new cap but not sure what else seals besides the oring.

 

[rolliges]

The gas cap equalizes pressure around a certain pressure; so there must be a valve in the there somewhere.