Gas Tank Leak

[ctxj93]

So today I filled up the MJ and noticed when I got home that it was leaking pretty good out of the sending unit cap. However, It's not leaking from around the sender or from where the steel lines go into it. My sender has this little plastic plug looking thing in addition to the steel lines and if I wiggle it around it will leak.

 

Any idea what this thing is for? I'll grab some pictures tomorrow because I'm sure my description isn't very clear. I don't usually fill my tank all the way, so this is the first time I've noticed it. 

 

Edit: I'm an idiot. I'm sure thats the connector to send power to the pump.  It seems like it's leaking around it, weird, I'll have to take a closer look under there when my exhaust isn't 10,000 degrees. 

[MEmanchie]

I'll be checking on this post I've only toped mine off once since I owned it and had fuel leaking from the top but didn't have a chance to check it out yet

[88whitemanche]

That has happened to me before. It's leaking at that specific o-ring...it happens a lot on our truck building so much pressure or that the gas disintegrate the o-ring itself....there's a write up in the DIY section which shows a part that rebuilds that area. I've done and by far no leaks and trust me I filled up a full tank and watched over half a tank drop out.

 

The re-assembly of the senders brought a new problem into light - the 'o' ring under where the harness enters the top of the sender is unique. it is standard in size (ID and OD) but it's diameter (thickness) meant it was not standard. I finally found it at the local NAPA store - it unfortunately does not have a part number so you would need to take the old one in for comparison.

 

 

Then, fastening the push nut so leaks do not occur:

 

 

 

and finally, re-attaching the other wiring and taping the openings (keeps bugs out) for storage:

 

 

 

We bought new locking rings and 'o' rings for the senders - they are still commonly available but we got ours at NAPA: http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?A=STPLO01_0261766611&An=599001+101989+50038+2038006&Ar=AND(P_RecType%3aA).

 

and, finished:

 

 

All-in-all, we spent about $60.00 for refurbishing the two senders.

 

My son's sender had developed a leak at the junction of the tube and the top (outside) plate of the unit - we ended up using JB Weld to repair his with good results. If either of the units here would have had non-working potentiometers I would have send them to the rebuilder, as adjusting the potentiometer is beyond the skills I have.

[ctxj93]

88whitemanche, You replaced the O ring and it fixed the issue? Does the o ring go on the inside sandwiched between the push nut and the sender cap OR on the outside of the cap OR on the outside of the push nut? It's kinda hard to tell from the pictures there. 

[88whitemanche]

Yes it did fix the issue....it goes in the outside of the sender like shown in pic #1 and once you place through the hole. you use a new push nut so it can grab onto the rubber part of the connector. It's a job to do to hold the deep socket and clamp in place. But once you get it in...it'll be all worth it

[ctxj93]

gotcha, cool deal. Any idea what size push nut to use?

[88whitemanche]

I remember exactly what the size was...but I did go to the help!!! Section and bought a pack of those push nuts at advance auto parts....they had different sizes and that pack had three of the same size push nuts for the fuel sender. Cost? 2to 3$

[88whitemanche]

Found the box in the truck I usually keep the push nuts and o-rings. Just in case if it happened again and I need to fix it in a parking lot or something....it's been a little over a year since I've been driving it since then and no problems yet.

 

Here's the part number of the box I got

 

[ctxj93]

damn you're the man! Thanks a lot that will make things easier

[comanchedude]

Right here is why these clubs and forums rock... the info that is available is just amazing..  Nice repair

[ctxj93]

For future information this is a sweet fix. I'm 99% sure it fixed my leak, but we got 3 inches of rain today so everything is a little wet under there. The parts number for that help kit is still the same, and the process works great. As long as your sender ring isn't seized on there super tight you can do this in well under an hour. It's easiest if you drop your e brake cable bracket.