leak at sending unit

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Ken71Twister

Ken71Twister

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I recently installed a new gas tank and sending unit on my 71 Duster. While under the car trying to figure why the gas gauge was intermittant, I noticed that I smelled gas and the area around the sending unit gasket was damp. Any guess as to what I should do to get a tighter fit? Should I look for a thicker gasket? Bend down the metal tabs to get a tighter fit with the gasket I have?
 
Some of the locking rings that come with the new senders are not as thick as originals. If you still have the original locking ring,
It may be all you need.
 
RedFish said:
Some of the locking rings that come with the new senders are not as thick as originals. If you still have the original locking ring,
It may be all you need.
Click to expand...

I agree, I just did the same thing a few weeks ago and had the same problem. The new lock ring was not as good as the old one. I made a thin fiber gasket to go under the ring on the sender side and reassembled, problem solved. Also make sure all three tabs are seated properly, mine kept wanting to walk to one side allowing for uneven pressure on the seal.
 
We had the same problem on a 69 Charger, had to use the old ring, and walk it in slowly.
 
If you don't find any difference in the gaskets, try the method I used. I installed mine with the rubber gasket between tank and sending unit. Then I used some thin gasket material and made another gasket which I installed between the sending unit and the lock ring. It took up the space enough to give a good seal.

Also if you have access to the proper tool to install the lock ring that would be a plus. You can get an even pull on it instead of tapping on one tab.
 
I had similar problems.. When you set the sending unit in place., it does not always stay put.. I tightened the lock ring by hand first prior to gently tapping around it at different spots until tight.

Prior to install I put a light coat of grease on the rubber seal as well, which seemed to help get it in just right.. No leaks since..
 
No need to reuse any old parts or make another gasket. This is a real common problem. All you have to do is look closely at the retainer ring for the sending unit. The "tangs" that tighten down on it as you turn it to secure it need to be carefully bent just a little bit before you install it. this puts the ring under more tension and causes it to compress the o-ring like it should. I've done it a good bit and it seals right up every time.
 
This is a common problem because many of the sending units are now made in China where they have poor quality control or bad specs to begin with. They like to cheap out whenever they can so we're left with junk. I had the same problem (as everyone else here did) and I too used the old gasket and retainer because the gasket is thicker and the retainer is made properly.
 
StrokerScamp said:
No need to reuse any old parts or make another gasket. This is a real common problem. All you have to do is look closely at the retainer ring for the sending unit. The "tangs" that tighten down on it as you turn it to secure it need to be carefully bent just a little bit before you install it. this puts the ring under more tension and causes it to compress the o-ring like it should. I've done it a good bit and it seals right up every time.[/QUOTE

I just re-read the OP and because you have a new tank, Strokers method should do the trick. I bent the tangs on mine and no help. I was using the original tank and just couldn't compensate for it, that's why I had to use another piece of gasket for a spacer if you will. The metal on the sending unit was a tad thinner than the original as well as the lock ring. The metal around the opening was weak and stretched so I had to resort to a hickabilly repair.
Click to expand...
 
I seem to have a leak-free installation (for now). Trying install the sending unit when the tank is on the car is way less than optimal. I decided to remove the tank and give the installation a better chance of success. I compared the new gasket to the old and thickness was the same. I used the wood handle on a hammer to tap down the tabs a little, placed the gasket in place, set the sending unit in place over the gasket, and then put the lock ring on. I noticed that the diameter of the lock ring was almost a 1/4 inch smaller than ideal - so it would be easy to install it far enough off-center to allow a leak. I don't know if I could have centered the lock ring while the tank was on the car because there's little room between the back of the tank and the differential and visibility is poor

For now, the tank is sealed up, there is gas in the tank, and there's no sign of leakage. I'll let you know if I run into problems after the tank goes back on the car.
tx,
Ken
 
Glad I found this was about to ask the same question. My sending unit had a lock ring that was WAY thinner then the original so I did reuse the original locking ring but new gasket. I have developed a leak now though. Reading this makes me feel it is probably that the lock ring has walked off track.

Any idea where to get the lock ring tool or a suitable replacement? I was going to use a brass drift.
 
jhdeval said:
Glad I found this was about to ask the same question. My sending unit had a lock ring that was WAY thinner then the original so I did reuse the original locking ring but new gasket. I have developed a leak now though. Reading this makes me feel it is probably that the lock ring has walked off track.

Any idea where to get the lock ring tool or a suitable replacement? I was going to use a brass drift.
Click to expand...

Year One.
 
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