Series 2 SU carburettors fuel leak

[inca]

Hi

Please excuse my basic level of knowledge here. One of my carbs, furthest from the bulk head, is leaking fuel. I have taken the lid off the float chamber and checked the needle isn't stuck. With the float chamber lid off I topped up the chamber with fuel only to see the level steadily drop down as the fuel leaked out from the underside of the main carburettor body. Reading up on this I think the problem may be the jet diaphragm, please could I have any further advice on this.

Is it possible to replace the jet diaphragm without having to remove the carburettor unit from the car and if this is the fault would it be worth changing all 3 diaphragms whilst I'm at it?

Many thanks

Mark

[christopher storey]

Mark : your diagnosis is almost certainly correct . The diaphragm rubber hardens with age and eventually splits . It is possible to change the diaphragms with the carburetters in place but it requires delicate fingerwork and a full vocabulary of swear words . You need to remove completely the air filter canister to gain access ( not a difficult job) . The bases of the chambers are held on by 4 screws, and you are best making for yourself a "right angle" screwdriver which is of assistance in initially starting the release of the screws, and in final nipping up of them on replacement . I would definitely replace all 3 given the price of fuel today. Burlen Fuel Systems have all the stuff in stock usually, and you can buy either kits or individual parts

[inca]

Chris

Many thanks. I ordered the replacement diaphragm and also spring and successfully replaced them - the old diaphragm did have a large split in it. Really appreciate your advice which gave me the confidence to fix it myself.

Regards

Mark