Do we have to drop our tanks to get at the fuel senders?

[rang-a-stang]

I thought I saw somewhere there was an access plate in the back of our jeeps under the carpet? I know my jeep has a fuel gauge sender and a separate pickup and I think i need to replace their gaskets. I don't want to pull all those metal runners off my carpet just to find out I thought wrong.

I just failed smog AGAIN because EVAP won't hold pressure, even though I replaced ALLLLLLL the lines down there
I really dont want to drop my tank, yet again, but will if I have too.

[ShagWagon]

Mines under the rear seat so no need for metal strip removal but I think they have no topside access in the older ones and tank has to be removed.

Maybe cut an access hole for next time if you have to pull tank out.

Someone else will know for sure.

[joe]

80 and up have a riveted access cover under the seat. 79 and earlier you have to drop the tank. Some late production run 79's used the 80 tub so have the cover but it's not common.

[babywag]

Yes, no access in floor on '79.
Take it somewhere that has a smoke machine...rather than hoping/guessing to find/fix leak?

Did you look @ rollover valve junk hidden behind rear quarter cargo panel?
If still there probably truly usless after almost 40yrs.

[Heavy_Metal_Thunder_81]

Nope. No access panel. And you can't really just cut an access hole because the sender is right in the middle of the "step" up for the rear seat and under a cross member.

[rang-a-stang]

Yes, no access in floor on '79.
Take it somewhere that has a smoke machine...rather than hoping/guessing to find/fix leak?

Did you look @ rollover valve junk hidden behind rear quarter cargo panel?
If still there probably truly usless after almost 40yrs.

I looked at it and it's connections and they looked pretty solid. I followed all the hard lines around and they all looked solid. I checked all the soft lines with a vacuum pump and they are now all solid.

If the rollover valve dies, does that prevent it from keeping pressure in the tank (during a smog check)? I noticed a slight gas fume smell when the smog tech was pressurising it and it failed really quickly so whatever leak I have, it's pretty good sized.

I am going to replace those 2 gaskets (or o-rings) regardless. If they are toast when I drop the tank, I will assume those were my problem and probably just take it to get smogged (for a third time). If the gasket/o-rings look pretty good, I will probably go get it smoked... or make a home made smoke machine and do it myself....

Nope. No access panel. And you can't really just cut an access hole because the sender is right in the middle of the "step" up for the rear seat and under a cross member.

Haha! Of course it is! Thats my luck! Nothing easy on this truck! LOL! Honestly, my tub is really solid and I don;t want to cut into it at this point anyway. I would rather just take the extra time and just drop the tank. I guess I kinda wanted to paint my skid plate anyway...

[asudchiman]

Here's what it looks like on the "newer" GW's.


Don't mind the "red" rubber seal. I got it from the plumbing dept and cut it to fit to help make sure fuel vapors do not enter the cab of the Jeep.

[rang-a-stang]

Here's what it looks like on the "newer" GW's.


Don't mind the "red" rubber seal. I got it from the plumbing dept and cut it to fit to help make sure fuel vapors do not enter the cab of the Jeep.

OK, cool. Thanks.

Anyone have a part number or the specs for the gasket? I don't see it at Rockauto, Autozone, or Oreilly...

Just remembered my church has fog machine and I could borrow it and use it as a smoke machine!

[Heavy_Metal_Thunder_81]

I had to take the o-rings to NAPA and match them up to some assorted ones they had in stock.
Silly question, but you have checked your fuel cap, correct?

[ShagWagon]

Nope. No access panel. And you can't really just cut an access hole because the sender is right in the middle of the "step" up for the rear seat and under a cross member.

Doh! Well NVM on that then if it sit on a crucial.

Just thought it would be worth it for future references/adjustments etc...

[rang-a-stang]

I had to take the o-rings to NAPA and match them up to some assorted ones they had in stock.
Silly question, but you have checked your fuel cap, correct?

OK, that's what i am going to have to do. Unfortunately, the NAPA here in Camarillo is staffed by a bunch of so I try to avoid them but I think that will be the only place I will find O-rings in stock.

Haha! Fuel cap is definitely NOT a silly question! Yeah, it's been checked. They check the fuel cap separately and it is passing.

I will smoke (actually fog) my system today. I'll let you guys know what I find!

[Heavy_Metal_Thunder_81]

Good luck! Let us know what you find.
I'm so glad I don't have to deal with emissions crap on mine.

[rang-a-stang]

Last night I hooked up the Fog machine. It blows plenty of smoke and it seems like it should work to provide smoke to show leaks but the smoke wouldn't enter my tank, it just blows back through the hose I taped to my fuel inlet.

I thought maybe I needed to provide a throughput so the smoke can pass through my evap system so I unhooked the line at the carbon can. No change. I hooked up a vacuum pump to the carbon can's line (to the tank) and it drew/held vacuum (it should not have because my tank was open). This means when I was working on my tank last, I hooked something up wrong.

I didn't have a lot of time last night so that's basically where I left it. Next time I work on it, I will lower the tank a bit so I can see all the lines on the top top and verify my routing. I also think I am going to check the flange where the gas cap sits because I am wondering if its bent from 40'ish years of use...

[tgreese]

Have you looked at the TSM? The TSM typically has a very good diagram of the fuel tank and its plumbing in the fuel section. There is a '79 TSM free to download and read here http://oljeep.com/gw/79_tsm/79_Jeep_TSM.pdf Look at figure 1J-4.

[rang-a-stang]

I sure did! In fact, I took the gas tank diagram, blew it up to page size, and printed a couple copies so I have some to take notes on and mark up while I am troubleshooting.

It's tough because I don't have a tool to pressurize my tank to troubleshoot. I have to inspect each line individually and look at my tank to hope I can see any cracks.