C2 sending unit

[Gary G.]

[Harry S.]

Re: C2 sending unit

A few things to try:

• See if the metal ring will tighten a bit more. The weight of the gas is probably pushing down on the bottom O-ring causing a space, thus a drip
• If you used a new reproduction rubber O-ring, replace it with an NOS O-ring. The NOS O-rings are a bit thicker than todays reproduction O-rings.

[Larry M.]

Re: C2 sending unit

Use GM NOS o-ring and metal retaining ring. GM #3825206 and 3774937.

Make sure leak is coming from o-ring and not the two electrical connection packing/seal joints.

Larry

[Gary G.]

[Harry S.]

Re: C2 sending unit

Gary, they come up very often on eBay. So, if some come up, buy a few as backup. The metal ring also.

Verify the part number -----> https://www.ebay.com/itm/17421242990...leYpxJ&vxp=mtr

[Leif A.]

Re: C2 sending unit

A bit spendy, but if it stops the leak...

https://shop.docrebuild.com/1963-1974CorvetteFuelTankSenderSealGenuineGM3825206NOS.aspx

[Frank D.]

Re: C2 sending unit

Here is the difference in "O" rings, repro (bottom) vs OEM (top); its significant:
And there are some things where I don't worry about price if the quality is there; e.g. fuel components, brakes, batteries.

[Larry M.]

Re: C2 sending unit

A bit spendy, but if it stops the leak...

https://shop.docrebuild.com/1963-1974CorvetteFuelTankSenderSealGenuineGM3825206NOS.aspx

Leif:

I agree........DR has them.

I was able to source two NOS from Ebay just last week for $5/each shipping included. So they still are out there.......but getting harder to find.

Larry

[Larry M.]

Re: C2 sending unit

Here is the difference in "O" rings, repro (bottom) vs OEM (top); its significant:
And there are some things where I don't worry about price if the quality is there; e.g. fuel components, brakes, batteries.

Frankie:

Agree 150%. You don't want to cheap out on getting this part totally correct.

Hope all is well with you and family. Miss your Corvette posts at CF.............

Larry

[Gary G.]

Re: C2 sending unit

First off, my apologies to all. After I drove the car a bit the leak returned and that gave me the opportunity to look at it and see where it was leaking from. It turns out that when I retightened the hose clamp, the hose itself split. I will however take the advice and order a new lock ring and continue to look for the O-ring. Hopefully one will pop up on EBay soon. Again, apologies and many thanks for the support.

[James W.]

Re: C2 sending unit

I ordered a new, NOS O-ring from Doc Rebuild this morning. Getting ready to reinstall my original '65 gas tank and sending unit and only want to have to do it once. I ordered some Dow Corning O-ring lubricant for the install.

James

First off, my apologies to all. After I drove the car a bit the leak returned and that gave me the opportunity to look at it and see where it was leaking from. It turns out that when I retightened the hose clamp, the hose itself split. I will however take the advice and order a new lock ring and continue to look for the O-ring. Hopefully one will pop up on EBay soon. Again, apologies and many thanks for the support.

[Larry M.]

Re: C2 sending unit

I ordered a new, NOS O-ring from Doc Rebuild this morning. Getting ready to reinstall my original '65 gas tank and sending unit and only want to have to do it once. I ordered some Dow Corning O-ring lubricant for the install.

James

I would simply use motor oil lubricant like St Louis did. See AIM for details. AIM is specific on this point.

Larry

[Harry S.]

Re: C2 sending unit

Didn't they have them soaking in oil in a bucket.

[John D.]

Re: C2 sending unit

Not to alarm anyone but here is something I have been thinking about on that baby teething ring.
One might think in the future the ethanol is going to destroy them. But so far I have not heard any complaints.
Maybe some one might have to make the o'ring out of viton rubber???

[Larry M.]

Re: C2 sending unit

Didn't they have them soaking in oil in a bucket.

Yes..............based on comments from the late JohnZ (John Hinckley) who was there as an engineer.

Larry