Ultra Low Sulfur Diesel

I am in that club as well. 2001 American Coach Tradition and "lift fuel pump" leak. Replaced and all is well!

wolfe10 wrote:
Interesting, as Caterpillar and Cummins both in writing say all their engines are OK on ULSD with no additives.

And if ULSD is such a serious problem, one would think that the OTR truck would be stopped all along the side of the highway with issues, as they do a LOT more miles with the same engines that we use.

^^Exactly. We have 45 OTR trucks here at work and do not run additives other than the winter blend to help with gelling, which I might add is a little more problematic with the ULSD vs. the LSD preveously used. The reason most of the leaks showed up in 2007/2008 when they switched over the ULSD is due to the lack of aromatics. When they strip the sulphur from the fuel the aromatics comes out with it. The new fuel systems take this into account. The seals mainly affected were those made of nitrile rubber (Buna N). Aged seals which did not adapt well to this change seemed to fail sooner.

Another "theory" on the leaking seals is that the new ULDS fuel is more susceptible to oxidation which would attack the seals and cause them to age prematurely. This is merely a theory though that was presented at a fuel seminar that I went to a few years back. Not really proven like the reduction in aromatics issue.

In 2007 when we first switched over to ULSD our lift pump on our Cummins ISL started to leak and I merely replaced it and went on our way.

My theory now is put as much fuel through it as I can by keeping the tires rolling down the road.:)

Mike.

Interesting, as Caterpillar and Cummins both in writing say all their engines are OK on ULSD with no additives.

And if ULSD is such a serious problem, one would think that the OTR truck would be stopped all along the side of the highway with issues, as they do a LOT more miles with the same engines that we use.

Use an additive, Optilube Summer Blend is my insurance policy which I chose based upon the study linked in another post.

Very inexpensive IMHO.

In 2007 the Cat Rep gave us the honest word. ULSD does not probide the neccessary lubricity for diesels and pumps and seals have and will fail. The Factory has to toe or is toeing the line dictated by EPA, just like when they told us small cars are safer than big SUVs with frames. In other words costly bs for Citizens.
He said to run a lubricity additive. There are only tw or three that come close on scoring or wear. Biodiesel was introduced just like ethanol was but a side effect is that as little as 2% bidiesel in your tank will increase lubricity to the neccessary level. The devil in it is that biodiesel will swell and rot seals and hoses especially mentioned hydraulic lift pumps in Cat and Cummins in engines prior to 08 production. I maybe wrong on the age. I noticed in Arizona and elsewhere that Biodiesel is just about all you can find so I fill up with ULSD or ULD if I can find it and add a little biodiesel but no more thant five gallon, in one hundred gallon tank. I wish I had a two hundred gallon tank. It would make the juggling easier. I got the understanding somewhere that to change health old seals and hoses would run over 3 thousand dollars and probably a lot more.
There are studies on lubricity products on the net. I had passed along a couple of them over time but don't know where they are now.
Don't follow the factory/EPA propaganda listen to the experts in the diesel engines and not neccessarily over the road truckers. They just drive them and don't do the maintenance etc.

That is only 5400 miles a year. A diesel likes to be run.

Ive ran additives for years. I had some irrigation diesels thar ran day and night so didnt add additive due to cost. Went out and one engine had blowby. Dealer told me to add an additive. By the next morning it was fine. A good additive like Stanadyne will clean injectors, lub the pump, and add cetane. Many newer fuels dont have high enough cetane. Cetane is how well the fuel will burn.

And here is one with a very good review of lubricity additives: DIESEL FUEL LUBRICITY ADDITIVES STUDY RESULTS. If you have a newer engine, you don't need to worry about this stuff.

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Ultra low sulfur fuel does not lubricate as well as the low sulfur fuel your engine was designed to use. The only diesel available these days is the ultra low. The fuel company is suppose to add additives to replace what was lost. The new engines are designed with this change in mind. There are additives you can use to replace the lost lubrication.

Seals do go out with age and you engine is 12 years old. If it sits which I imagine it has since it only has 65,000 miles. The seals could have dried out some as well.

This may help clicky