fuel tank breather tank series 2

[jory21]

THE small breather tank in the LH quarter panel has 4 tiny openings for hoses. Where do they all go and is it vital that they are correct? I have an English S11 2+2

[chrisvine]

The external pipes that you can see have different lengths within the tank - I stuck a piece of wire up with a kink/hook at the end to find out their lengths:



The shorter one (A) is the return to allow fuel to return to the main tank. Of the other three, the two closest together are to allow fuel to pass from the main tank to the expansion tank (when the fuel expands in a full tank). Fuel enters the top of the expansion tank through B/C and pools at the bottom outlet A. The other is vented to the outside or back into an emissions device (I think) for US cars. There is a Jaguar bulletin about it somewhere - I'll post it if I can find it.

The other ends of the pipes A, B & C are attached to the fuel tank as shown. Inside the main tank, pipe B & C end very close to the underside of the top of the tank and hence why fuel only passes to the expansion tank when the tank is full. I think there are two pipes due to the internal baffles. The return pipe A ends about an inch lower allowing fuel to return, once the level in the main tank has dropped below the ends of B & C. Hopefully that makes sense!



By the way, has the expansion tank been removed from the vehicle. I'm trying to get the rough dimensions of the tank for someone, as repro expansion tanks aren't available.

Chris

[MarekH]

You'll also find details of the vapour expansion tank in the pocket book US (tan coloured) s3 Owners Manual.

(I still have your steering column piece Chris btw.)

kind regards
Marek

[chrisvine]

Finally found the bulletin:

Jaguar Expansion Tank Bulletin

Marek - thanks. Unfortunately I missed the last gathering at Bicester. Happy for you to keep hold of it until another suitable opportunity or I could PM my address.

Chris

[nefematic]

Here a shematic layout of the system, from the Service Manual (E.123E/2) for Jaguar Fuel Evaporative Control System. According to this, Chris sheme mixed up B and C on the tank?

Martin

[chrisvine]

Martin - your diagram is much better than those in the bulletin and you're correct that I have the two swapped the wrong way round on the fuel tank.

.... although I don't think it would make a material difference as the two pipes in the expansion tank are identical in length. Certainly not enough to take the fuel tank out again to correct!!