Modern fuels damaging rubber components?
Barrie Jones, who has an MGBGTV8 and is the TD/TF Technical Specialist for the T Register, set out his concern that modern fuels containing bio ethanol appear to be attacking the rubber components in the carburetters and fuel pumps of our MGs. He urges V8 members to inspect the carburetters and fuel pump on their V8 for leaks as a regular safety check and if you become aware of any such problems, please would you post your reply on this thread. If you prefer to send Barrie an email I will set up an automatic response form .

Barrie says: I recently had a severe fuel leak from one of my TF SU carburetters and it appears that the rubber seals have perished and failed where the float chambers are connected to the body of the carb. Once I started looking, I also found that the fuel pump was starting to leak where the casing is joined together by 6 cheese-head screws. I think the problem is with the diaphragm.

I also recently replaced a fuel hose with one which had `suitable for unleaded fuel' printed on it. The new hose cracked and disintegrated within 6 months of fitting! I know, my TF shouldn't have those rubber seals, but they were an improvement fitted to some MGAs to prevent fuel frothing, so I made the change many years ago.

My concern is that modern fuels appear to be attacking the rubber components in our carburetters and fuel pumps, and since petrol has recently had up to 10% Bio-Ethanol added to it, I am worried that I may be seeing the tip of a rather large iceberg. I would recommend that all your register members inspect their carburetters and fuel pumps for leaks as a regular safety check.


If you become aware of any such problems, please would you keep me informed? For my part, I have contacted Burlen Services (the people who have taken over SU Carburettors) about this matter, and I shall forward their reply when I receive it.

Posted: 11.1.08


See also the useful briefing note from Barrie Jones and reports of known problems, a response from a English V8 member in the US John Targett. and an update from Barrie Jones.

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You can send your comments or views on this technical topic to Barrie Jones using an online response form