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Ron Z.
Ron Z., - Dodge Tech -
Category: Dodge
Satisfied Customers: 18773
Experience:  18+yrs experience. State Inspector and Dodge Diagnostics
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2007 dodge ram 1500: vacuum line going..rail

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2007 dodge ram 1500 4.7V8 stock shortbed reg cab with the "Gascap" light on.
codes P0457 and P0456
No luck with the cap, but I do know I don't get the vacuum air rush sound when I remove the cap anymore.

I I didn't see any cracked lines.
I removed the vacuum line going to the filler neck and capped it, and hooked a hand vacuum pump to one of the lines along the frame rail nothing. no vacuum.
The lines aren't that easy to get to especially on top of the tank.
Is there a chance that I'm missing something ?
The lines look really good .
Any suggestions ?


Was the fuel cap replaced?


Customer: replied 7 years ago.
yes , replaced the cap no joy


Was the vehicle running while you were fuelking up at any point?


Customer: replied 7 years ago.


Ok. I just found a Technical Service Bulleting provided by Dodge on this issue. Can you give me your production date? This can be found on the white tag on the driver's side door jamb.


Customer: replied 7 years ago.

sorry it took a little while.

There was no production date label on any of the door jams.


I couldn't find any date info under the hood either.




Ok. Using the VIN#, it does look like this TSB applies to you. The problem has been aknowledged by Dodge and the cause is a faulty Charcoal Canister. The TSB repair calls for the replacement of the canister, filter and fresh air hose. Depending on your warrenty coverage, it may be fully covered.



Customer: replied 7 years ago.

OK, now I'm just asking here, would that cause a vacuum leak , say an internal leak of the canister that would not let the fuel tank hold vacuum ?

I 'm used to hearing that vapor /vacuum sound when unscrewing the gascap, and I don't anymore . Lending credibility to the fault light.



Absolutely. According to the TSB, the canister is a faulty design, and has loose pieces of charcoal inside. This will cause the entire system to not hold vacuum at all. These TSB's are put out right from the factory, and are pretty reliable. The TSB also says that the Dealer will have to do a "smoke" test to verify the problem, but i'd be willing to bet this TSB is right on the money.


Customer: replied 7 years ago.

Wow, That sounds pretty good.

Now you mentioned that the TSB mentions replacing the canister.

Does it have a kit part number ?

Also, what other lines does it say to replace.

(I don't think the lines are bad , but just in case)



More than likely, this all comes as a pre-made kit. If they suggest changing it, I would change it, even if it "looks" good.


Customer: replied 7 years ago.

Sounds like a winner, I'll give it a shot first thing in the AM.


For you quick response !!



You're welcome. Glad I could help. Have a great day!

Ron Z. and 3 other Dodge Specialists are ready to help you
Customer: replied 7 years ago.

Drive Fast71,

Just a follow up on the 2007 Dodge ram 1500 wuth the "gascap" fault. P0457/P0456

Thanks for helping with the TSB info on the charcoal canister.

I went to the dealer and picked up the TSB kit, and replaced it, reset the code, and started her up. ....WINNER !!----no fault light or code.

The charcoal canister was where the internal leak was.

Thanks again for the technical assistance !!


This is one for the notebook.



You're welcome. Glad I could help. Chalk another one up for the good guys! Have a great day!