Fuel leak advice

[GreigM]

Ok, so working through my issues with the car, and it always had a strong petrol smell, well today I figured its got a pretty major fuel leak. After a bit of running it drips down just in front of the drivers side rear wheel off the chassis underneath. I think there is a pipe which runs along the drivers side then goes vertical (I'm guessing to the tank) - and it needs replaced or something done to it.

Or is there something else I can look at that commonly leaks in that area?

And how is it for accessibility for someone with a jack and some spanners - is this an exhaust-off, fuel tank out type job?
First picture is to show the location of where it's dripping:


2nd pic is an attempt at showing the pipe which goes vertical which I suspect may be the cause, its definitely wet (sorry, poor pic):

and here you can see the very wet chassis:


Still on my first tank of fuel since buying this car

 

[Roscobbc]

Strange considering that fuel (and return) pipes run from the tank to the fuel pump on the passenger side of the car. It's generally the short rubber connection tubes that will degrade and leak.

 

[johng]

If it's on the drivers side then it's probably the pipe that goes to the evap cannister you can see it on this photo

 

[curious bystander]

Are you sure it's petrol and not brake fluid?

 

[antijam]

Strange considering that fuel (and return) pipes run from the tank to the fuel pump on the passenger side of the car. It's generally the short rubber connection tubes that will degrade and leak.

As Rosco says it's odd to find a fuel leak on that side of the car since all the fuel lines normally run along the passenger side. I don't want to teach my Grandma to suck eggs but are you sure that's fuel dripping? It's an ideal spot for a brake fluid leak. It's not easy to tell from your piccies but a vertical pipe run in the rear driver side quarter is usually a brake line which is in a high corrosion area and can be prone to failure.

edit. Just noticed CB beat me to the same question.

 

[GreigM]

Are you sure it's petrol and not brake fluid?

1000000% its fuel

 

[GreigM]

If it's on the drivers side then it's probably the pipe that goes to the evap cannister you can see it on this photo

Yes, I reckon that's it, sigh, not an easy fix then.

 

[Roscobbc]

If it is

Yes, I reckon that's it, sigh, not an easy fix then.

Yes......but if an 'evap' return line shouldn't that only return vapour.....and not relatively large quantities of condensed liquid?
Presumably a later C3.....are we sure that 'if' that is the reason for the leak that it should be leaking that much liquid? and there's not an issue at the 'engine end' with a malfunction of the float valve in the carb or an overly high float level?

 

[teamzr1]

Is the fuel filter located in the rear and leaking there ?

I would not think EVAP would have raw gas volume to leak that much out as it should only be some fumes from the intake manifold

Better jack car up and look higher to see where gas is leaking downward
Leaking gas tank ?

 

[johng]

I'm pretty sure there is a "valve" that stops liquid going down the evap line but allows vapour. I reckon this "valve" has failed and presumably you also have a leaky pipe as well. Don't know how easy it is to replace the Valve (it might be called a liquid separator) or the pipe without taking the body off or at least dropping the tank. Easiset thing would be to cap off the vapour line from the tank and fit a vented fuel cap.

 

[teamzr1]

There should be a EVAP hose map under the hood like this


Could take pulley AIR pump for a test and cap off hose from canister to tank

 

[Corvetteville]

Strange considering that fuel (and return) pipes run from the tank to the fuel pump on the passenger side of the car. It's generally the short rubber connection tubes that will degrade and leak.

 

[Corvetteville]

I had a fuelly smell on my 78. I removed the body filler flap & the rubber boot, & you'll get to the sender, as in the picture. There are 2 short rubber hoses between the metal pipes of the sender & the metal fuel lines. You can see the jubilee clips in the picture. The two pipes on the right are the fuel lines towards & back from the fuel pump on the engine.
Feel around the pipes to see if there's a leak. My rubber pipes were soggy & perished. I managed to replace them without dropping the tank. It's fiddly but is possible. You'll need long nosed pliers & I used spring pipe clips instead of jubilee clips as it's impossible to tighten up the outer ones as they're under the bodywork. I took the old rubber pipes to my local motor factor & got a couple of lengths. They're different diameters, same goes for the clips. I got a box of assorted sizes of eBay
Hope that's of some help.

 

[Mr. Cricket]

I about soiled my shorts when having filled up then drove home to find a steady stream of raw fuel pouring out just behind the drivers front wheel (1971). The car was parked on a slight slope with the drivers side lowest and it was overflowing from the charcoal filter. Once it dropped a bit stopped and I kept that in mind on future fill-ups. Could it be that the fuel has travelled down the frame to the rear of the car?

 

[teamzr1]

Did the fuel gauge show full when fueled up ?
How long was the drive home and what does the fuel gauge report now as
this would give an idea of if steady leak or not

Since gas dries up pretty quickly, with key on so pump is running, start looking upper engine and see if signs of gas flowing downward
Maybe gasket for the pump, fuel filter, fittings for them, carb leak, etc

Any paper or cardboard around, so the car can be parked over it and then see where gas spots shows on them

 

[Roscobbc]

Stuart - fuel pump being up on right hand side of engine - fuel line (and return pipe if your car has one) are as you know clipped to outer part of frame........so either a corroded/damage fuel line or possibly (as you note running fuel may be 'wicking; along the outside of pipe).........car is about that age where and rubber connecting pieces will have finally be affected by time and now ethanol........had this happen to mine a few year back.......OEM rubber tubing section connecting short length of metal fuel tube from side of fuel tank - to chassis pipe runs. Piping started to become porous and was weeping fuel........but dripped directly on to ground at rear of car.

 

[Grahamred70]

While we're on the subject of fuel lines the rubber hoses must be R9 spec to resist the new higher levels of Ethanol, my 1970 C3 runs quite happily on E10 although it has got a fairly new carb fitted.

Graham