#970 Fuel Pick up leaking at elbow

[kkosche]

Got rear of the car in the air replacing the parking brake pads.

Came into the shop today to the smell of gas.

Upon investigating, fuel is weeping from top of tank (tank is full) . . . at the fuel pick up / fuel gauge sender. Right at the 90 degree fuel pick up elbow, between the elbow and what looks like a metal washer (not between the washer and the nylon bushing / seal). Maybe that "washer" isn't suppose to be a washer?

Questions:

1. Can I disassemble the pick up and replace just the elbow? Common components?

2. If I need to order an entire sending unit . . . recommendations as to where.

3. Common problem?

I appreciate your council.

Here is a picture of the situation:

[Blas]

The photo does not reflect a completely standard offering MKIII sending unit. It appears to have been modified by a previous owner. Looks like a pipe fitting was added to the top.

[madmaxx]

in a pinch use SealALL it will stop gas leaks but make a permanent repair. I used it to seal a gas leak on the bottom of a 66 chevrolet gas tank in 1988 and the car was sold in 2000 and the seal all was still holding, LOL

[kkosche]

Where would I go about purchasing a stock replacement unit that would be bolt in?

The previous owner ran a few different induction systems (8 stack, various carburetors, etc) . . so maybe the "modification" was some remnant of those attempts. Once I get my car back on all fours, I'll remove the sending unit and see how it has been assembled / modified.

I used SealAll on a powered surf board gas tank I was messing with last year . . . worked well . . but would like to solve this one more along factory lines if I can.

Thank you both.

[Mark IV]

It looks like the sending unit has been modified with a return line for fuel injection?

We can supply the standard sending unit but if you require a return line it too will need to be modified. Perhaps the existing unit can be removed and the fitting sealed?

[PANAVIA]

if it is braised in , then they probably didnt do such a good job. I would replace the stock sender with a replacement and plumb the return line properly in say the filler neck, there may even be a port there to take advantage of.

the main thing with plumbing the return line to that fuel gauge sending unit piece, is that the unit metal is sooo very thin there, that any vibration will contribute to this condition /problem being repeated.

where is the car now >?

Steve

[Blas]

I would think that a return line there would interrupt the flotation device when the fuel is return to the tank?

[kkosche]

It was indeed a previous owners plumbing of a return line. A hack job. . . hole looks like it was made with a file. Combination of washer, pipe fitting, nylon washer and a jam nut. I bet it was leaking / weeping since the day it was installed.

Car is currently is running a Holley HP950. No near term plans to need a return line. The hose you see in the picture was about 3' long and the end was plugged with a nut and hose clamp.

Attached is my slightly better, hack job. 1/2 bolt secured with SealAll. Cutting a new gasket for the sending unit, letting the SealAll dry and I will reinstall. Gave me a chance to make some minor adjustments to the float, in an attempt to get a more accurate read (fuel gauge reads past full when tank is full).

I think I will order a replacement sending unit in case my slightly better hack job does stay sealed. . . or for the next time I take the sending unit out.

I welcome further comments . . and I thank those who have commented already.

[TN Shelby Cobra]

Don't want to steel this thread but I have another question about the gas tank. Has anyone adjusted their float. My gas tank when full registers full . When empty it says 3/4 tank. I know years ago on my first car ( A 69 Mach 1) I just bent the rod a little and it register more like what was really in the tank. Can we do this on or Superformance cars? Thanks guys! Great site! , Mark

[Blas]

Rated at 20 ohms when full and 240 ohms on empty.
or:
NOTE: Sender has resistance values of 240 ohms at empty - 67 ohms at half scale - 20 ohms at full.(the higher the fuel level, the lower the resistance.)

[spf645]

Originally Posted by TN Shelby Cobra

Don't want to steel this thread but I have another question about the gas tank. Has anyone adjusted their float. My gas tank when full registers full . When empty it says 3/4 tank. I know years ago on my first car ( A 69 Mach 1) I just bent the rod a little and it register more like what was really in the tank. Can we do this on or Superformance cars? Thanks guys! Great site! , Mark

TN SC

Your wasting your time trying to get the sending unit to read correctly. I spent half the day trying to do so. I think the tanks are 16gal. So I just drained mine, put in exactly 4 gal. and made sure the gauge read 1/4. Adding another 4 gal. the needle reads close to 3/4. And then 4 more, it's past full mark, yet with room for 4 more. You might want yours adjusted where it would read 1/2 with 8 gal. Up to you, but don't waist a lot of time.

Now I know on mine anyway,, 1/4 means,,, hunt some gas SOON. It was embarrassing being the last car to leave local cruse night when car wouldn't start with gas needle just above E, and rear of car parked slightly down hill. That's what lead me to try and adjust mine, along with seeping gasket.

I'm sure others have tried, and maybe with better luck than I. Careful though bending sending unit arm, don't think it could take lots of bending before breaking. Best of luck.

[TN Shelby Cobra]

Thanks! I will give it a try! Nothing worse then running out of gas!! Mark