Lower sulphur causing vehicle diesel pumps to leak

Enemalta said today that it was now importing diesel with a lower sulphur content, and this was causing some vehicle diesel pumps to leak because of poor sealing.

Reacting to complaints from motorists that the diesel pumps in their cars have sprung leaks and that mechanics were blaming the quality of the diesel fuel supplied, the corporation explained that an EU directive stated that as from January 2009, it had to start selling sulphur-free diesel only. The sulphur content of this diesel was actually not more than 10ppm. Up to December 2008 the permissible sulphur content of diesel fuel was 50ppm.

Enemalta said that this was not a problem concerning the quality of the diesel but simply related to the drop in sulphur content that might cause the rubber seals in the diesel pumps to contract, leading to diesel leaks.

If the rubber of the seals was not tough enough, then the rubber might crack and the seal would start to leak diesel. In such cases, diesel vehicle owners should replace the said rubber seal, the corporation said. This would be a once-only change.

Should the seals not be leaking, their rubber would have adapted well to the change and there was no need for replacement.