just something i stumbled across
Tech Sheet
‘The Sulphur Debate’
The Sulphur debate seems to be the ‘Scape-Goat’ of this century! Since the start of the year
there has been an epidemic of leaking diesel pumps most prevalent in 4WD’s and small commercial
diesels. It is only happening in these vehicles with a ‘rotary’ pump fitted, due to the fact that a
‘rotary’ pump is running and lubricated solely by the diesel fuel whilst the ‘in-line’ style pump,
found mainly on earlier 4WD diesels and in heavier commercials, is running mainly with engine oil
lubrication. Of course we have been shouting loud about the problem for a while (through the 4WD
magazines and our ‘tech sheets’ whilst the Diesel Associations are keeping their pockets warm.
Anyway, I’d just like to quickly run through this terribly misleading DIESEL FUEL debate
and give you some clarifications from the Pro’s...Berrima Diesel! You’ve probably been reading
about ‘HORROR STORIES’ (like up in Queensland) of the removing or reducing of Sulphur in
Diesel fuel. These stories would lead one to believe that pump damage will occur and seals will
leak. It is being heavily published as being so in leading 4WD publications, TV and even by ‘so called‘
Diesel Industry Associations!!
THIS IS ALL WRONG and misleading!!!!!! We at Berrima Diesel have been saying from
Day 1 that if it leaves the nozzle as International and Australian standards dictate ( and I wish the
Federal Government would Prosecute if it wasn‘t ), the fuel will have all the characteristics that it
was intended to have. Robert Bosch didn’t have these standards to assure him when he built the first
diesel fuel system for Rudolf Diesel. He was using vegetable oil (peanut oil was one of them!) and
it worked for him. Let’s not forget that there never really was diesel fuel then as there is now.
Diesels then and today will run on a light oil (if a tad smoky!) without refining.
One of the ‘stories’ being told about removing the Sulphur is that it reduces the lubricating
qualities of Diesel fuel. This is true BUT, as we have always said, it will still have to pass
lubricating standards before being labelled Diesel. Even if it needs lubricants adding (All the Oil
Companies backs this up!)!! Diesel is barely a lubricant at the best of times (WD40 rings a bell) and
if it is watered down with other industry ‘by-products’ it qualities are reduced even further!
The other ‘stories’ flying around about pump seals leaking is another bit of a con! Even the
Oil Companies have a little excuse for it but I don’t fully believe that! Yes, composition does have
an effect on the seals but we have new and old 4WD rotary pumps leaking, and not all the seals in
the pump leak. These O-ring type seals have to cope with a lot of adulterated diesel. Adulterated
diesel can contain (and we have seen it contain!!) some highly aggressive (to injection components
and seals) substances. This combined with pump fuel operating temperatures running higher than
manufacturers could believe (we‘ve tested fuel temps in hot weather up over 80‘C coming out of
the pump!! Pump manufacturers say to stop testing pump delivery on the Test Bench once fuel
temp. goes much over 65‘C) leads to (usually the thing leaking) the top cover seal contracting or
expanding, twisting and then leaking. As far as the stories of front seals filling sumps with fuel and
dirt being sucked in by others is sheer that ’scare tactics.‘ Certain questionable Diesel Industry
bodies saying that ‘once the seals are replaced with new ones it won’t happen again’ is misleading!
In fact we dare the ‘Diesel Repair Industry’ to come clean and stop saying pumps need complete
rebuilding, for 99% of the time it is only a number of top cover seals that need replacing! With the
fuel samples we are seeing here at Berrima Diesel at the moment, anything can happen in the future with leaks! So make sure that if they are being replaced that they are being replaced with
GENUINE seals.
Diesel 4WD owners and potential buyers (if they are still even interested in buying a diesel
4WD), shouldn’t read too deeply into the problem, keep their fuel receipts and hammer their Fuel
supplier and local Federal Member about he problem!! Barbara has been doing this for a while and
has actually, although they would never recognise it (a member of the public bringing it to their
attention), achieved discussion and proposals happening in Federal Parliament as we speak. We will
keep you updated on that.
Most Oil Companies have officially announced that they are doing a back-flip on the
Sulphur debate. They have finally come clean on the fact that sulphur reduction IS NOT causing the
leaks but instead it is the imbalance in aromatics in fuel brought on by the reduction of the sulphur.
I wonder what next will be blamed.
We still say a mixture of factors. Incorrectly balanced diesel, mixtures of adulterated illegal
fuel and/or old age!!!’
At the end of the day, if you notice that you have a leaking pump, don’t panic and don’t
worry about getting it towed home from Birdsville. Just get it fixed as soon as you can.