Farmers report more problems with blocked tractor fuel filters

Urgent action must be taken to resolve ongoing problems with blocked fuel filters in tractors and other farm machinery, NFU Scotland says.

The union has reported that once again farmers across the UK are facing problems linked to biofuel levels in red diesel, with no signs of recompense or solutions to address the issue, which first surfaced in October 2019.

NFUS said specifications and standards of fuel were being cited as the problem, adding that the introduction of improvements to fuel specifications had been slow.

See also: Red diesel: The problems uncovered

The rise in cases of blocked filters has been attributed to a legal requirement to increase the proportion of fuels derived from renewable sources in diesel and petrol products.

Blocked filters have been blamed on an increase in the fatty acid methyl ester (FAME) content of red diesel fuel, which is made from various combinations of fresh and recycled vegetable oils and some animal fats.

In the meantime, farmers and crofters have been left with bills running into thousands of pounds for replacement parts and fuel treatments.

Jamie Smart, NFUS transport adviser and a member of a cross-industry taskforce set up to tackle the issue, said urgent action must be taken to address filter blocking.

Blocked paper-type fuel filter

© NFU Scotland

“Testing of fuel samples has shown that most fuels reach current standards. However, given that some fuel is still blocking filters and causing vehicle breakdowns, it is simply not fit for purpose,” he said.

“As a result, fuel filter blockages in tractors and motorised farm machinery remain a regular and costly problem for many Scottish farmers and crofters.”

‘Unacceptable’ problem

Union vice-president Robin Traquair added: “The continued problems related to filter blocking are unacceptable. As farmers and crofters, we are purchasing fuel from reputable suppliers and we need that fuel to be reliable for our businesses, so we can continue to put food on the nation’s table.

“The filter blocking issues have meant that some filters are lasting for a tiny proportion of their intended use. The cost of repair, down time and replacement parts are being shouldered solely by the users.”

NFUS said it was the responsibility of the British Standards Institution (BSI) and the fuel chain to push forward with the specification changes to ensure that agricultural diesel is fit for purpose and filter blocking problems “are resolved once and for all”.

Union members who are currently experiencing problems with blocked fuel filters are being encouraged to report issues on the fuel filter hub on its website, or contact their regional manager or the NFUS Agricultural Vehicle Helpline on 07733 136 424 or email