P0455 after changing fuel pump

[flyin-lowe]

Thanks for the info, still learning here.... When first replaced the fuel pump the light came on the first time within a few miles. Once I tightened the gas cap and cleared the light it didn't come on again for a couple hundred miles.

 

[Brain75]

Be glad it is a ford and not a gm.....
Here's a re-post of the official GM OBD2 training proceedure:

GM General Motors OBD Driving Cycle

I have a Pontiac that NEVER trips the evap - because getting that one has to be done in a lab basically. Thankfully both states I have lived in allow 1 monitor not ready. No CEL because it is old enough they don't turn on the CEL for it. The newer ones turn on the CEL for everything.

 

[flyin-lowe]

Being new to Fords and dealing with this issue for the firs time I started looking around yesterday hoping to see an obvious issue before I take the bed off again. Looking between the bed and the cab a portion of the fuel pump barely is visible. The gasket/o ring I put on is a green color and I noticed I could see part of it in that area between the top of the tank and the metal locking ring that holds the fuel pump down. I honestly cant remember when I took it apart how the fuel pump and gasket all fit together at the top of the tank. If the locking ring is not seated correctly cold that cause this code. I have watched a few youtube videos but can't really see any angles that show if the o ring is visible in spots or not.

I know when I put the lock ring on I had the fuel pump pushed down and made sure each slot was into place when I tapped it into position.

 

[franklin2]

Being new to Fords and dealing with this issue for the firs time I started looking around yesterday hoping to see an obvious issue before I take the bed off again. Looking between the bed and the cab a portion of the fuel pump barely is visible. The gasket/o ring I put on is a green color and I noticed I could see part of it in that area between the top of the tank and the metal locking ring that holds the fuel pump down. I honestly cant remember when I took it apart how the fuel pump and gasket all fit together at the top of the tank. If the locking ring is not seated correctly cold that cause this code. I have watched a few youtube videos but can't really see any angles that show if the o ring is visible in spots or not.

I know when I put the lock ring on I had the fuel pump pushed down and made sure each slot was into place when I tapped it into position.

The fuel system has to be totally sealed, or it will fail. If you go to the station and fill the tank all the way to the top, and gas starts leaking out around the sending unit, then yes that is a problem.

 

[flyin-lowe]

I found 1 youtube video that shows kind of what I am seeing. Based on it I think my locking ring is probably on correctly. I took a screen shot from his video with the pump in and pressed down and you can see the gasket between each of the tabs. Once he put the locking ring on the angle is a little from above so I am not sure if the gasket should be visible or not. I think I am going to try a smoke test before I take the bed off. I dont think it would be possible to miss one of these tabs and still get the locking ring tapped into place as rigid as they are.

 

[flyin-lowe]

Thanks for all the replies. I have found the problem. Based on the recommendation above I went ahead and filled it up with gas at the station a mile from my house. When I got home I could see the top of the tank was a little wet around the fuel pump, so there is an issue with the seal. I am guessing it is operator error on my part. Time to take the bed back off and see what is up. Not what I was hoping for but need to get the issue taken care of. At least it has all new bed bolts so that part won't be an issue.

 

[Brain75]

Don't know about the 98+, but since manufacturers are getting cheaper not better I bet they still have the same issue... all the 2nd/3rd gens (maybe 1st?) want to do is cross thread like crazy when you screw the plastic retainer ring on, you got to verify you aren't getting cross threaded then pound the thing home once you know it is true.

here's a vid of a 3rd gen - watch from 2:55 to about 5:25. note she has to hammer it literally with a hammer and punch to get off and on tight, and she has everything off with lots of room and she still fight it getting crossthreaded at least once before the edit.

(hers is a '94 - 3rd gen)

 

[flyin-lowe]

Thank, on mine there is no plastic retaining ring. Just the metal lock ring like in the screenshot I posted above.

 

[franklin2]

Thank, on mine there is no plastic retaining ring. Just the metal lock ring like in the screenshot I posted above.

I had a terrible time with my sending unit leaking on my old Tahoe. It had a plastic tank, but those ears like in your picture were steel. They were molded into the tank and had rusted. The rust had bulged out and deformed the opening where the o-ring goes, and it would not seal. In this case I could not find another tank and ended up revamping the whole fuel system with a 2dr Tahoe tank mounted at the rear. It was a steel tank and easy to get. What a can of worms that turned out to be. But I finally got it.

 

[flyin-lowe]

That sounds crazy. Hopefully mine is just a case of me not noticing it want right when I put it back together and nothing major.

 

[flyin-lowe]

Finally got my issue fixed, unfortunately I had to get another fuel pump assembly. Once we got the bed back off today I found a nipple on top that one of the lines goes into had broken off somehow. Hot really sure how it happened but it was. Put another fuel pump on it and so far so good. I kind of looked and there really isn't any logical way that part of the bed broke it off when I was putting it back together last time. Also I had driven it for a week or two before the CEL came on. Either way, it appears as if it is fixed now.

 

[flyin-lowe]

Just can't win with this thing. So far the truck is driving great and no more Evap code, but the fuel gauge is still pegged at full with over 150 miles driven so far....