U.S. EPA Region 3
March 2, 2005 - 1:30 PM


Arleen Shulman - PA DEP
Chris Trostle - PA DEP
Ernie Kline - North Penn School District
Eric Cheung - Clean Air Council/PDD
Lionel Gillston - Diesel Engine Transformations
Joe Grinkewicz - School District of Philadelphia
Mark Ulrich - Cummins, Inc.
Ron Gilbaugh - Unionville-Chadds Ford School District
Gail Wolfel - Unionville-Chadds Ford School District
Marianne Cleary - North Penn School District
Jack LeBeau - E Global Solutions
Roger Leisenring - Sunoco
Debbie McNeal - Sunoco
Bill Ross - Sprague
Paula Krall - U.S. EPA, Region 3
Ray Chalmers - U.S. EPA, Region 3
Brian Rehn - U.S. EPA, Region 3
Ken Brown - UPenn

Minutes Taken By: Eric Cheung

Meeting Chaired By: Ray Chalmers

Ray Chalmers graciously agreed to Chair this meeting of the Technical Sub-Committee.

The objectives of the Technical Sub-Committee's work concerning the ULSD/fuel pump is issue was set out in the February 24, 2005 Executive Committee Conference Call minutes:
1. Determine what information concerning North Penn ULSD/fuel pump problems is available and what the methods are for obtaining it.
2. Determine who the Technical Subcommittee should be partnering with (EPA? Diesel Technology Forum?) as part of its exploration of the ULSD/fuel pump problems.
3. Compile all relevant information concerning the North Penn fuel pump problems, especially the specific make-up of local school bus fleets that have participated in diesel retrofit projects, as well as information on ULSD issues nationally.
4. The end product should be a Frequently Asked Questions (FAQ) document that primarily summarizes what information is available and only draws limited conclusions about what that information means. All information presented should be backed by supporting documentation that can be made available to interested parties.

Eric Cheung noted that so far he has received information from North Penn concerning buses that have experienced fuel pump problems. Marianne Cleary added that her fleet has not experienced any recent problems. She asked whether more information from North Penn is needed, but explained that she cannot offer maintenance records for those buses that experienced failures, as such records were not kept.

Eric requested from Marianne a full list of all buses in North Penn's fleet with model years, engine types and other pertinent information, so that the Sub-Committee could have a fuller context of the extent of the problem.

Mark Ulrich stressed there is a distinction between failure modes having to do with 2001-2004 Cummins engines and those having to do with the pre-1994 Cummins engines. Prior to 1994, Cummins engines, like other heavy duty engines in the industry did not necessarily use Viton fuel pump seals. As Roger Leisenring noted during his February presentation to PDD, when fuel systems switched to Viton seals in 1994 they no longer experienced leakages. The 2004 engine problems are of a different character and are not the leakages or seal pump failures that pre-1994 Cummins engines in the North Penn fleet have experienced.

Eric asked what was known about the failures with the GM engines. Bill Ross replied that GM has extended its engine warranty, which will end up covering all of North Penn's failed GM buses. He noted that the rate of pump failures associated with GM engines (Stanadyne fuel pumps) is not out of the ordinary and believes that they need not be a major focus for the Technical Sub-Committee. He added that he did not think the problem with the Stanadyne fuel pumps had anything to do with seal failures and might be unrelated to ULSD. Ray asked whether GM could issue an official letter acknowledging problems with its fuel pumps and explaining that it has extended warranties relating to them. Members of the Sub-Committee felt that it was unlikely that GM would ever issue a letter acknowledging problems with its engines.

Returning to the Cummins engines, Roger says it is important to establish failure rates for vehicles, so that it can be determined whether the problem is out of the ordinary. Marianne said North Penn's fleet normally experiences 3-4 bus failures a year. It has experienced 20 failures after switching to ULSD in a three-month span.

Mark Ullrich noted that Cummins issued reports analyzing the failures of the 1990 engines and the 2004 engines. These reports were made available to the Technical Sub-Committee. The report concerning the 2004 engines says the failure is due to "air ingestion in low pressure fuel system or aeration of fuel due to restriction in low pressure system." As for the pre-1994 failures, Mark pointed out that they represent a total of 14-15 buses. This amounts to only an 18% failure rate.

Roger observed that the type of problem associated with the 2004 engines may be the result of filter plugging and filter plugging could happen with any manufacturer's fuel pump system. Filter plugging may not have anything to do with ULSD at all and may have a number of explanations, including biological activities or how the fueling tanks were drained in preparation for the switch to ULSD. Jack LeBeau asked whether anything could be recommended to other fleets to decrease the chance of a filter-plugging incident. Marianne echoed Jack's concern saying what she really was hoping would be for the group to come out with some specific recommendations to offer other fleets so that they could avoid North Penn's problems. For instance, she wondered if it would be helpful to advise fleets switching to ULSD to also replace their filters at the same time.

Brian Rehn from EPA asked whether Cummins has issued a bulletin warning fleets about the potential for fuel pump failures. Mark noted that the Washington DC Metro Area Transit Authority (WMATA) has used the same Cummins engines in their fleet as North Penn's 2004 vehicles and have not experienced problems at all. He stressed that the failure North Penn experienced is specific to the 2001-2004 Cummins engine fuel system. Unfortunately, none of the filters from the failed systems were saved, so Cummins has no way of definitively claiming that plugged filters were the problem or what the source of the plugging was. He reiterated all that Cummins knows is that the fuel system failed due to high pump inlet and there may be a number of causes for this that have nothing to do with ULSD. Furthermore, Cummins checked the lubricity of the ULSD and it was not an issue.

Mark said he was not aware of other failure modes other than seal leaks for pre-1994 Cummins engines and high pump inlets for 2001-2004 engines.

Marianne asked whether the group could at least issue a statement listing things that a fleet needs to watch out for while transitioning to ULSD, such as filter-plugging. Gail Wolfel from Unionville-Chadds Ford added that perhaps a bulletin from the Technical Sub-Committee would be useful offering things for fleets to consider doing prior to switching over their fuel. Gail said that the language need not mention specific engine makes.

Roger asked whether Cummins was coming out with a bulletin concerning failure modes relating to its 2001-2004 engines. Mark said Cummins is planning on putting out some type of statement concerning these engines. But he also stated that the problems North Penn experienced with its engines are not unique to Cummins. He urged the Sub-Committee to focus on 1) the type of failure mode at issue 2) what is causing the failure and 3) what can be done to fix it when issuing recommendations rather than identifying specific engine manufacturers.

Jack asked whether it would be costly for fleets to simply replace existing seals for pre-1994 engines with Viton seals preemptively before switching to ULSD so as to avoid failures. Marianne clarified that the cost of a bus failing is more than just the cost of replacing the fuel pumps. There are also towing expenses, increased bus driver hours, and phone calls from worried parents to consider. These other costs suggest that it may be cheaper for a school district to preemptively switch seals in order to avoid mid-operation failures. But, Marianne admitted, even had she been advised to replace her seals before ULSD, it is unlikely she would have done so, because the cost of replacing fuel pumps is expensive.

Brian suggested that the Sub-Committee does not need to know the exact causes of failures, but rather what the most likely causes are in order to provide some guidance to fleets prospectively considering diesel retrofit projects. Ray reiterated that he would like to get statements from the engine manufacturers concerning fuel pump failures their vehicles have experienced.

Eric said he will work with Roger and Bill to try and come up with a list of maintenance practices that can be used to compare and contrast North Penn's fleet with WMATA and/or Wissahickon, so that maintenance guidance can be issued by the Sub-Committee. Brian also had some ideas about information he would want collected from fleets that have used ULSD.

Mark repeated that in his opinion the failure modes for 2001-2004 Cummins engines have nothing to do with the use of ULSD. Marianne said she understood this, but the issue may be that the transitioning from current diesel to ULSD created the conditions that enabled the failure. She wondered if Cummins is looking at this issue and trying to come up with suggestions to solve the problem. Mark responded that Cummins is not looking into the problem of fuel pump problems for these engines, because from the company's perspective, there have not been enough failures to suggest a systemic concern about using ULSD with its engines.

Eric reviewed the information that he needs to collect: 1) a full breakdown of North Penn's fleet 2) any bulletins or statements that Cummins has put out relating to fuel pump failures or suggested maintenance for their engines that may be of use to the Sub-Committee 3) any recommendations offered by the Engine Manufacturers Association issued from the early 1990s in response to failures back then 4) a comparison of maintenance practices between North Penn and WMATA and 5) any GM statement relating to fuel pump failures for their engines.

When a question was raised about New Jersey Transit's recent problems, Bill responded that its fleet has not experienced any more or less engine problems than usual since it began operating on ULSD.

Eric asked the Sub-Committee whether there were some other outside groups that may have helpful information. It was suggested he contact the Technology Maintenance Council and the Diesel Technology Forum.