8 replies to this topic

[mini macey]

I am still battling with a fuel leak.

Macey is a 1995 Rover mini 1275 and I am new at this!

The fuel is leaking down the paint work, it only happens when the tank is over 3/4 full. I have replaced the rubber that sits on the body work around the pipe from the tank. I have a new vented fuel cap with new rubber seal. The actual fuel pipe into the tank looks fine. There isn't an especially strong smell of fuel in the boot so I don't think it is leaking inside. First I thought I had a vented fuel cap when its not needed but as my engine is injection I understand I need the vented cap.

So Im stuck.. it must be a simple answer surely...!


Thanks for reading

Ellen

[cooperdan]

Is it a constant flow

[mini macey]

There is always a film of petrol over the paint work unless the tank is below 3/4. The flow to the engine seems fine as the car runs lovely

[cooperdan]

Are you sure its not just where you fill up and you pull the nozzle out too quickly and dribble down the side abit...

[mini macey]

Pretty sure. I've been extra careful ever since I noticed it. I clean the petrol away as soon as I see any but it returns. As I said I have changed the petrol cap because I thought it could be something as silly as when I nip round a corner petrol spills out. Its just from where?!

Am I right about the vented cap?

[Stevie W]

Hi Ellen,

You may want to have a closer look at the end of the filler neck where the fuel cap fits onto it. Sometimes the seat of the filler neck can become dented/bent due to the action of placing the fuel pump filler nozzle into the tank neck. If this seat is dented/bent the filler cap will never seal properly and going round right hand corners with a full tank will allow the petrol to leak out between the seal and tank neck seat.
Also there is a kind of bayonet fitting inside the end of the filler neck which pulls the fuel cap down tight against the neck seat. If this is worn it will also cause a fuel leak. Try fitting the cap as normal and then try to turn it by hand. It should be tight and you should not be able to turn it easily.

Hope this helps!

Steve.

[mini macey]

Thanks Steve

The replacement cap I brought just as a tester was the non locking one so I have to screw it on and it is pretty solid when its on there. I'll re examine the filler neck in the light. I can't see what else it would be.
Would this mean a whole new tank to repair it or can you buy filler necks separately?

Ellen

[Stevie W]

Hi Ellen,

The fact that it screws in tightly shows the bayonet fitting is pulling the cap down tightly, so that leaves the filer cap seat.

I have repaired these in the past using a number of assorted tools. Basically if the seat is bent/dented downwards (or upwards) it can be made flat again. I have used a small block of wood under the seat and gently tapped the top with a rubber mallet.

Two things to be aware of is using anything metal as hitting metal with metal can cause sparks.....not good with an open filler neck!
Also be careful not to drop anything down the filler neck during straightening the seat!

It's best to work a little at a time and check if you are improving the flatness of the seat or making it worse as you go!!

See what it looks like tomorrow.

Steve.

[Darkscamp]

from my experience of having an spi mini, you need a non-vented locking petrol cap. the spi is a pressurised system that has a venting circuit to cut back emissions.

they are harder to find at shows but easilly distinguishable by the base being red not green

this is the one although the website is out of stock by the looks of it

http://www.minispare....aspx?pid=33983