porsc911t

I like to have a happy ending to a post, and my truck has passed emission testing. The evap leaks were found on the gas tanks. Instead of dropping the gas tanks I removed the entire truck bed to expose the tanks and hoses. Very simple process of unplugging the tailights and removing six bolts. Rubber grommets for the rollover valves were shot and the gaskets for the fuel pumps leaked also. I replaced every grommet, gasket, and hose for the system just to be safe. It passed this morning and case is closed. I am very excited to tow my boat to the lake now. Thanks for all the help everyone!

- Andrew

slosvo

where were you able to buy all the gaskets and such?? does the dealer still sell these parts.. I'm in the same boat as you..in az too

porsc911t

Autozone had the pieces I needed. They were not labeled as the parts required (roll over grommet was just a pcv grommet instead). Depending on what you need, I can provide part numbers and assistance. Did you fail a pressure test? What year is your truck?

slosvo

I have a 94 f150 with a 5.8. 185K on the clock. It did fail the pressure test part of the evap test..Which I quite don't understand how the test works since the charcoal canister has two vents on the top of it.. is it that they just pressurize the tank that the roll over valve shuts from the pressure and only the tank gets pressurized??

Anyway , A buudy of mine has a smoke machine that I can borrow.. but I was going to just pull the bed off and do a visual...if i can't see anything i will smoke it before the bed goes back on..

porsc911t

I wish I had the bed off my truck to show photos but once you have yours off it will be real simple to see the evap lines. The photos I have attached show my canister and the hoses coming out of it that I replaced. The metal line from the engine compartment will end right at the bed and become rubber hose. That rubber hose will "T" into two lines, one for each tank. It plugs into the rollover valves which the grommets for those could be the issue. When I went to my local autozone, there was only two pcv grommets hanging on the shelve. One was too small and the other was a perfect fit. I would hope that even though we have different motor sizes, the gas tank setups will be the same. I also had to remove my fuel pumps and clean up the gaskets because a lot of dirt was in and around them. If you have trouble putting them back on it could be that they (gaskets) have shrunk over time. I just made mine fit again so I would not have to go to the dealer for the part. The last thing to check for leaks would be the filler necks. Tighten the hose clamps real good and they should be fine.

I wish I could give you the exact part number for the grommets but I couldn't find it. This is as close as I could get and it may not be right:

http://www.autozone.com/autozone/par...er=720821_0_0_

Hope it passes!

porsc911t

Ran by Autozone and snapped a shot of the grommet that was leaking on my tank's rollover valve.

bubbabud

Went through the same thing with my 1990 ranger. I found it much easyer to just un bolt the bed and lift it off then all of the plumbing is right there it turnd out my leak was the filler neck hose right near the top. a little syilicon and a hose clamp got me passed

slosvo

see those two "mushroom" tops.... they are vented to the atmosphere.. thats what i don't fully understand about the evap test and the pressure they add in... unless the roll over valve closes with the pressure...

slosvo

So I pulled the bed off the truck,, everything looked good.. up until I came to the junction of where the two rollover valves come together.. actually it was where the rear tank goes back to rubber near the junction.. it was wet there and the hose was mushy.. so needless to say i replaced that hose.. the pics are kind of ****ty.. but hope it helps someone.. I still don't quite understand how the Evap test works as both rollover valves have another hose that has a vent on it.. so how is the pressure test ever going to work??? well we shall see as i am taking the truck in for its retest...

porsc911t

I wish I had photos of mine to show and compare because we have two different rollover valves I guess. On mine, only one hose comes from the valve, it is where gas fumes from the tank would travel through to the engine compartment. I'm not sure why you have a hose coming off the rollover valve in each direction. Hopefully someone with that setup can chime in for you.

As far as the pressure test, I'm sure you can go in the Emission office before you run it and ask for how it works. They told me that they push 1/2 pound of air through the system. I didn't ask for more info on it.

Good luck on your test.