Fuel leak at sending unit - Fixed

[boonies]

I replaced the rubber o-ring, but still getting seeping at the junction of the tank and the sending unit.

Tank And sender seem flat. The tabs on the sender were a little bent inward and I straightened, but still leaking.

All suggestions are welcome.

 

[dang]

When mine leaked I tried a couple different o-rings until it was a really tight fit. Hard to turn. That finally fixed mine but not sure that's your issue. I used and o-ring off my shelf so I don't have a part number

 

[HB Chris]

What size hose are you using? Most use 8x13 but 7.5 fits better, it could be the hose/clamp.

 

[Eric V]

Hi Boonies, if the plastic collar on the outlet fitting inside the fuel hose is cracked fuel will seep into that same area and look as if the O-ring is the problem. You can blow air into the filler pipe vent hose to pressurize a little while you watch the area to see just where it’s leaking.

 

[boonies]

What size hose are you using? Most use 8x13 but 7.5 fits better, it could be the hose/clamp.

Not sure of the hose size, there is a bushing on the inlet, I have some other hoses I can try, but seems to be from the sending unit seal since it weeps from the tank top when I push down on the top of the tank.

 

[Eric V]

Hi Boonies, also check and be sure that the O-ring groove contact surface in the top of the sending unit is not corroded, needs to be smooth and clean and shiny with a light smear of white grease.

 

[HB Chris]

Wondered if you had the plastic bushing

 

[boonies]

Hi Boonies, if the plastic collar on the outlet fitting inside the fuel hose is cracked fuel will seep into that same area and look as if the O-ring is the problem. You can blow air into the filler pipe vent hose to pressurize a little while you watch the area to see just where it’s leaking.

Thanks, will check it out. Don’t remember if it was cracked when I replaced the line.
Ar

Hi Boonies, also check and be sure that the O-ring groove contact surface in the top of the sending unit is not corroded, needs to be smooth and clean and shiny with a light smear of white grease.

thanks, both surfaces are clear of any corrosion. I hadn’t tried the grease and will do so.

 

[dang]

The tabs on the sender were a little bent inward and I straightened, but still leaking.

Maybe they were creating more pressure on the o-ring?

 

[boonies]

I took the busing out of the line and it was cracked, so I will plan on ordering a couple of new o-rings to see if that makes a difference and try to source a replacement fuel line bushing.

 

[Eric V]

I took the busing out of the line and it was cracked, so I will plan on ordering a couple of new o-rings to see if that makes a difference and try to source a replacement fuel line bushing.

When I looked into this several months ago the bushing was not readily available so I sealed it with the tiniest smear of epoxy, put it in a tiny clamp, wiped away all traces of overfill, reassembled with patience and care so as not to disturb the sealed crack and to make sure the metal pipe, bushing, hose and clamp all fit perfectly, and it hasn’t seeped a bit after several months of nearly daily driver duty. Nonetheless I would buy a new one or two if readily available now.

 

[Stevehose]

Try some silicone lubricant on the o-ring so the sender can turn fully shut without resistance from the o-ring

 

[Wladek]

I see that the fuel tank paint in the sender unit area started to peel off, so maybe, before putting new o-ring, grind/flatten the area where oring is smashed with 1000 sand paper or so.

 

[E9madada]

The hose looks very wet, are you that the leak is not from there?

 

[Mot27cars]

Repair book says removing the rubber o-ring and letting it set 24 hours will allow it to reform its original shape. Tried this and no success although it was 46 years old.
Ordered a new one. Perfect now.

 

[boonies]

Work in progress now, thanks for the advice.

• Took the sending unit out again and have the o-ring warming in the sun (might be too impatient to wait 24 hours)
• Sanded the top of the tank around the paint chips with 800 grit sandpaper
• Plastic bushing was cracked from end to end, applied epoxy in the crack and have it setting up now in a clamp under light pressure

Thanks again for the advice, fingers crossed...

Lance

 

[Phemisg]

I'd be replacing that hose, using a proper auto hose clamp, making sure the ring is seated, and using two big screw drivers to tighten it down. Assuming the plastic spacer repair works.

 

[boonies]

Unfortunately the plastic repair did not take, I am going to try it again, but may need to transition to a brass reducer to transition from the smaller sending unit outlet to the standard fuel line.

 

[Phemisg]

You might look for a 8mm to 6mm tubular reducer with barbs on it. Probably quicker.

 

[boonies]

You might look for a 8mm to 6mm tubular reducer with barbs on it. Probably quicker.

Thanks, that is plan B. I am in the middle of another epoxy fix now, letting it cure for 4-6 hours. Meanwhile, have ordered this reducer.