Leaking fuel sending unit

[Ffranzwa]

Hi everyone. Can someone tell me what I'm doing wrong? I bought a new fuel tank, sending unit (Van's) and lines (Inline Tube) for our '66 300. Before I strapped up the tank, I installed the sending unit, centering it into the notch on the tank, put the gasket over the unit and tightened the lock ring with the proper tool. Excited, I started filling the tank. At about 16 gallons, fuel started pouring out of the bottom of the sending unit. After siphoning gas back out, I loosened the ring, took out the gasket and visually checked the new parts as compared to the OEM and looked fine. I mistakenly ordered another gasket and lock ring (I didn't know that they were supplied with the new tank), so I decided to try the other set. Got everything back together and... well you know. So now I'm pissed since I want to move on from fuel and into brakes. Any suggestions?

 

[FURYGT]

The reproduction lock rings are problematic. Try using a Chrysler lock ring.

 

[azblackhemi]

Or if you don't have a factory lock ring you can try using two gaskets. That has worked for me.

 

[CBODY67]

Should the gasket/seal be between the sending unit and the tank? Or did I read that wrong?

Many others have noted the apparent non-robustness of the aftermarket lock rings, similarly noting to re-use the production Chrysler lock rings instead.

CBODY67

 

[Just Carbs]

Should the gasket/seal be between the sending unit and the tank? Or did I read that wrong?

Many others have noted the apparent non-robustness of the aftermarket lock rings, similarly noting to re-use the production Chrysler lock rings instead.

CBODY67

Should the gasket/seal be between the sending unit and the tank?
Bingo.

 

[halifaxhops]

Should the gasket/seal be between the sending unit and the tank?
Bingo.

Yes. The new lock rings are to thin, reuse the ole one or find a nos one.

 

[Blusmbl]

Detroit Muscle Technolgies has the correct thicker lock ring, it measured as thick as the original I have. The gasket goes between the tank and the sending unit as well but that was already pointed out.