Diesel Fuels, Air Vapors And Your Engine: 3rd in a series of articles
The FASS Heavy Duty Series was designed for Class 8 Trucks.
The FASS Platinum Series is used by diesel pick-up owners.
The FASS Titanium Series can be used on a Class 8 diesel or pick-up truck.
By Steve Pollock
MARTHASVILLE, MO....Today's diesel fuel presents many challenges to a truck owner besides the "High Price." While cetane levels, lubricity, water, dirt particles and waxing have all been discussed in detail, entrained air/vapors in the fuel have not. Although comprehensive data is available through such companies as Cummins, Detroit, Caterpillar, Racor, MSOE (Milwaukee School of Engineering, the foremost school of hydraulic engineering) and other Fortune 500 companies, this data is hard to discover in public articles. Brad Ekstam, President of Fass Fuel Systems and an expert about diesel fuel and entrained air/vapors, has volunteered to enlighten us in a series of interviews. In previous interviews with Brad we found out how the entrained air/vapors get in the fuel and how they affect performance and injector wear.
In our third interview we will learn how the entrained air vapors are removed and the benefits associated with doing so.
Q. Movin' Out: Brad, how did you discover that air vapors were an issue in diesel fuel in the first place?
A. Brad: Having trucks of our own, we noticed that one of our new trucks would run great at first and would then suddenly perform inconsistent. After many trips to the dealership while under warranty, it was determined that air in the fuel was causing the engine to run rough and perform inconsistent. We were referred to a Cummins service bulletin from 1965, explaining how air & vapor separate and become evident in the fuel filter, causing the engine to perform poorly as it passes through the fuel system. As the fuel filter does its job, tiny bubbles collect on the outside of the element. These air bubbles rise to the top of the filter. As the air collects at the top of the filter, it replaces fuel until the equilibrium reached on the dirty side of the filter element. At this point the entrained air is pushed through the fuel filer into the injectors, causing a slight retarding of the engine's timing or a "miss." At this point if you would stop and refill your fuel filter you could eliminate most of the "miss," at least temporarily.
Q. Movin' Out: The FASS (Fuel Air Separator System) was developed specifically to remove air/vapor from diesel fuel, how does this work?
A. Brad: We designed the FASS Fuel System to pressurize the fuel after it leaves the water separator. As the fuel enters the fuel filter, the remaining air is trapped by the filter's element (along with dirt) and the air then rises to the filter's top as described in the Cummins Service topic. The FASS System then pumps clean, air-free fuel from the bottom of the filter to the fuel rail. The air passes through the extreme top of the fuel filter, as it does on a conventional filter and described in the Cummins Service Topic. But instead of passing to the engine the FASS is ported at the top to route the air/vapor back to the fuel tank with the return fuel being supplied with the FASS's fuel pump. Pure fuel is supplied to the engine from the bottom of the fuel filter to where the air will not reach under normal operating conditions. This is due to the fact that air rises to the top; this is where FASS separates it. The end result is that the FASS Fuel System recreates ideal factory test cell conditions for real time working diesel engines.
Q. Movin' Out: What are the performance benefits of removing air/vapors from diesel fuel? And what are the mechanical benefits?
A. Brad: The performance benefits that the FASS Fuel System provides to diesel engines are increased horsepower/torque and consistent optimum engine performance all day long. RPMs will be more consistent at an idle and the engine will be more responsive during acceleration. Many older engines will even shift smoother. The engine will seem quieter and truck will vibrate less, also making it easier to bump a dock due to the fact that the mirrors are vibrating less. Removing the entrained air/vapor will also eliminate the "miss/roughness" when idling. Mechanically, the FASS System will solve a lot of injector issues in a diesel engine. The result is not only having the injector perform properly, but it will also extend injector life as well with increased lubrication. The FASS System will also help extend fuel pump life as well.
Since the FASS fuel pump is circulating 150-260 gallons of fuel per hour, it is continually "polishing" all the fuel in your tank. This Mass Volume Return of fuel will even polish the varnish build-up inside the fuel tank and help with algae problems. Using an algae conditioner is still recommended however. The FASS System delivers impressive cold starts. The FASS's fuel pump is very strong allowing the truck to start in extremely cold temperatures even without a winter diesel additive, unless of course the filter is completely gelled. The system will also prime itself in the event you run out of fuel.
Q. Movin' Out: Are the results the same for pick-ups and Class 8 diesels?
A. Brad: While many of the benefits of the FASS System are similar for diesel pick-up trucks and Class 8 tractors, the results are a little different. Conservative driving pick-up truck owners typically see a mileage increase of 2-3 mpg and a gain of about 15 horsepower. Class 8 truck owners see improved performance that is consistent. Most conservative drivers are gaining a solid .4-mpg in fuel economy with some Mercedes and Volvo owners gaining up to .7 mpg. Most Class 8 trucks gain about 30 horsepower and lower their pyrometer temperature on stock engines by about 50-75º and modified engines by up to 150º. Most drivers are gaining 5-7 mph on uphill grades, typically gaining a solid gear on hills.
Q. Movin' Out: Are there other benefits associated with using the FASS System?
A. Brad: Some other benefits from installing a FASS System include extended life for fuel filters and water separators. FASS fuel filters are typically good for 30,000-50,000 miles. The FASS water separator uses a stainless steel wire mesh lining and many drivers are seeing 2-3-4 years of service before replacement. The FASS System was designed so that replacement fuel filters can be obtained from FASS, Fleetguard, Baldwin and other popular brands. The FASS pump motor has a life of around 17,000 hours or around 700,000+ miles. FASS uses a time proven, high quality pump that has a less than 2% failure rate. If the FASS pump should fail, it has a bypass mode that allows the truck to keep running. The FASS System comes with an available 4-year warranty and will not void engine manufacture (OEM) warranties.
Q. Movin' Out: Is it difficult to install the FASS System? And what kind of maintenance is involved?
A. Brad: Installation of a FASS System usually takes about 4 hours and can be done by anyone with a little mechanical inclination. A full set of step by step instructions, complete with photos, are included in each kit. Installations can also be done at any of nearly 700 FASS distributors nationwide. With pick-up trucks, the FASS unit is installed under the bed in front of the rear wheel on the fuel tank side of the vehicle. On semis the FASS unit replaces the primary fuel filter. Maintenance consists of emptying the water separator and occasionally changing the fuel filter and separator as needed.
Entrained air/vapors are an inherent problem for all diesel engines, including Class 8 trucks, pick-up trucks, marine engines & etc. In next month’s article we will review some actual customer testimonials from FASS Fuel System owners. Real results from real people.
Kevin Rutherford of ATBS, Bruce Mallinson of Pittsburgh Power, as well as thousands of Class 8 truck and diesel pick-up truck owners endorse the FASS System.
The folks at FASS Fuel Systems welcome your questions and comments. You can call their technical department at 636-433-5410 or email them at email@example.com.
You can also visit FASS Fuel Systems at the following trucking and pick-up truck events:
Semi Trucking Shows –
- Walcott Truckers Jamboree, Walcott, IA
- All Truck Nationals, Carlisle, PA
- Great American Truck Show, Dallas, TX
- Canadian Truck Rodeo, Quebec, Ontario
Diesel Pick-Up Shows –
- Dodge Pick-up Show, Pahrump, NV
- TS Outlaws, Bowling Green, KY
- Ballie Diesel Racing, Springfield, MO