Fuel Sending Unit Leaking...AGAIN!
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,242
Likes: 12
From: Kalispell MT
Fuel Sending Unit Leaking...AGAIN!
About 3 years ago I installed a new tank, sending unit, o-ring, & cam lock; all new parts. It took 4 attempts to get it to seal without a drip at the time.
A couple of months ago I came home to find a puddle of fuel in the garage floor, so I drained the tank and ordered more o-rings & cam locks to have a selection to choose from. I finally got time today to get the car on a lift and dig into again. Old o-ring looked fine (puzzling) so I mic'd the new o-rings and picked the fattest of the group and reinstalled everything with a new cam lock. Poured in some gas and it started dripping from the sending area immediately at the low side of the o-ring (it's not the tube either). Drained the tank and pulled sending unit again, no issues with seal damage.... OK so then made a shim to fit between the cam lock and sending unit (not in contact with o-ring which is on the other side of the sending unit base) in an effort to get better o-ring compression. It helped a little but not a complete fix.
What is the purpose of the tab on the inside radius of the o-ring? It appears to not be an alignment notch to anything or am I missing something?
Has anybody had similar issues? How did you fix it?
This is really driving me nuts!
A couple of months ago I came home to find a puddle of fuel in the garage floor, so I drained the tank and ordered more o-rings & cam locks to have a selection to choose from. I finally got time today to get the car on a lift and dig into again. Old o-ring looked fine (puzzling) so I mic'd the new o-rings and picked the fattest of the group and reinstalled everything with a new cam lock. Poured in some gas and it started dripping from the sending area immediately at the low side of the o-ring (it's not the tube either). Drained the tank and pulled sending unit again, no issues with seal damage.... OK so then made a shim to fit between the cam lock and sending unit (not in contact with o-ring which is on the other side of the sending unit base) in an effort to get better o-ring compression. It helped a little but not a complete fix.
What is the purpose of the tab on the inside radius of the o-ring? It appears to not be an alignment notch to anything or am I missing something?
Has anybody had similar issues? How did you fix it?
This is really driving me nuts!
2026 Loser of the Year
Joined: Sep 2013
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From: New Or-leens Loo-z-anna
The only thing I know.....the correct o-ring will require a LOTof force to squeeze it down when tightening the locking ring.
If you aren't bracing yourself to tighten the ring....for some reason the o-ring isn't thick enough (maybe the design is slightly "off" on the new tank that you installed)
If you aren't bracing yourself to tighten the ring....for some reason the o-ring isn't thick enough (maybe the design is slightly "off" on the new tank that you installed)
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,242
Likes: 12
From: Kalispell MT
Thanks doorgunner.
That's why we made the shim because it just seems too easy to rotate the cam to the full lock position. We are using a cam wrench. I'm guessing it's a case of too many different tolerances stacking up againist me. I probably should have spent the extra $$ for an original style OL Anderson tank.
That's why we made the shim because it just seems too easy to rotate the cam to the full lock position. We are using a cam wrench. I'm guessing it's a case of too many different tolerances stacking up againist me. I probably should have spent the extra $$ for an original style OL Anderson tank.
Team Owner
Joined: Sep 2006
Posts: 31,274
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From: Westminster Maryland
Hi Ray,
Are you absolutely sure the lock ring is being FULLY set?
I don't use a cam wrench. I use a brass punch and small hammer to tap sequentially on the lock ring tabs until I can feel (and see) that each tab is completely tight against the body of the sending unit.
I feel as though I get a better 'set' doing them a little at a time but in sequence.
Maybe?
Regards,
Alan
Are you absolutely sure the lock ring is being FULLY set?
I don't use a cam wrench. I use a brass punch and small hammer to tap sequentially on the lock ring tabs until I can feel (and see) that each tab is completely tight against the body of the sending unit.
I feel as though I get a better 'set' doing them a little at a time but in sequence.
Maybe?
Regards,
Alan
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,242
Likes: 12
From: Kalispell MT
Hi Alan,
I haven't tried using the punch for the final setting, but yes the cam wrench appears to get it fully to the hardstop tab and up on top of the ridges. I'm going to try finding a fuel safe o-ring that is slightly larger in thickness and maybe a softer durometer as well on Monday. For this weekend I'm calling it quits on it, tied of getting a gas bath.
Thanks again for the tip. Will use the brass punch for the final seating next weekend.
I haven't tried using the punch for the final setting, but yes the cam wrench appears to get it fully to the hardstop tab and up on top of the ridges. I'm going to try finding a fuel safe o-ring that is slightly larger in thickness and maybe a softer durometer as well on Monday. For this weekend I'm calling it quits on it, tied of getting a gas bath.
Thanks again for the tip. Will use the brass punch for the final seating next weekend.
