[stephen]

I starved my 97 45 foot XL of fuel on my driveway even though I had 100 gallons on board. I had the 208 gallon standard tank plus the 90 gallon aux tank. My driveway is steep and with the nose pointed downhill I got almost into the garage when it died.

I added about 30 gallons and primed it and it started up. I filled it and could only get about 130 gallons in it so your problem might be the slope has moved fuel away from the pickup.

[Greg]

I have a 99 with the same tankage….I tore mine apart a few years back and changed the fuel transmitter thinking I had a problem. As I got into it it became apparent that the “aux” tank has no sending unit, only the main and that the tanks are inter connected by a large, perhaps 2 inch fill line near the top and 3/4″ inch line at the bottom . I guess its the nature of the beast but mine burns down to between 1/4 and 1/2 tank and stays there until (I presume) all of the aux fuel is used, then it begins burning down again. Your fuel gauge only reads the 160 gallon tank, only odd part is the generator fuel pick up, just perhaps your engine hook up was placed on the generator stand pipe? It really begs for a one way check valve between the aux and the main, no matter what! Now, if you have the CC glass dash…start there and disregard the above:)

[Archived]

My 99 40 footer did the same thing just east of Denver. I have heard folks say the bus will only use all but about 30 gallons. I went through several fuel sending units untill we got one to work correctly. I have the SilverLeaf dash and have had consideralbe problem getting it calibrated. Prior to calibration, I installed a Prevost mechanical gauge under the dash and relied on it as opposed to the SilverLeaf.

To be on the safe side I would only count on using about 220 gallons before filling up. When I ran out in Denver I could only get 212 gallons in it.

[Jim]

I assume that the Aux tanks is not as tall as the main tank and the sending unit is in the main tank. That being said you should see a fast drop in the fuel guage until the fuel level in the main tank reaches the level of the top of the aux tank. Since liquids seek there own level, the fuel levels in the the two tanks should them draw down at the same level until empty and this should give you a slow draw down rate once you reach the level of the Aux tank. One tank is not going to reach the bottom fast than the other so I see no need for a one way valve on the connecting hoses. It does surprise me that the vent hose on the Aux is larger than the lower draw connecting hose.

[Jerry]

Ignore the gauges. Regardless of which coach I had and I have had 3 tank sizes, 250, 298 and now 208 I use a specific distance as my drop dead refill point. I have learned if I have steep grades a full tank is required. Whatever unit of measurement you use, mileage or engine run time, let that be the standard for refills.

[Archived]

I have learned that the fuel pickups are at the rear of the main tank so when going down hill with low fuel will exspose the pickups to air. while going up or down hills I can watch my Prevost manual gauge go back and forth.

I have also learsned the fuel pickups don’t go to the bottom of the tank therefore leaving about 20% of the tank capacity unused. I don’t really understand why they are made this way. I am sure to not pick up tank trash, but with the Racor filter plus the spin on filters, I would think this would be unnecessary.

[John]

Explains a lot. I have the standard 160 but have never been close to putting that much into it. I have gone down to below the pickup for the generator. So with 15 percent on top unusable and 20 percent unsable were looking at 35% of the tank unusable. The most I have every put into it was around 110 gallons. I alway thought that the bottom of the tank had 20 years of debris in the bottom.

[Archived]

Theoretically we should not have any accumulated crud in our fuel tanks. Most fuel pumps have filters to prevent debris from getting into the tank, but the reality is different. We fueled in OK once and by the time we got to northern NV the coach was starving for fuel. The cause was a dirty sludge the clogged the filters in our Racor as well as the primary and secondary filters. After a few filter changes the problem went away, but there is no doubt in my mind that some of that dirt or sludge ended up as a layer of silt that sat on the bottom of the tank.

Also our coaches which sit for extended periods are subject to the growth of algae. Even if we use additives to rid the tanks of algae that which doesn’t get loosened and trapped by our fuel filters could end up on the bottom of the fuel tank.

But my greatest concern about running a tank low on fuel is not debris as much as it is the temperature of the fuel. Excess fuel is returned to the fuel tank and it is hot. We have fuel coolers on some coaches and some DDEC monitors fuel temps.

[glen]

The Silverleaf that I have shows fuel temperature and I really don’t know where the sensor is located but I have seen 145 degrees a couple of times.

[Archived]

I change all my filters at every oil change. It’s cheap insurance.(With exception of air filter.)

Should we use an algecide in our tanks ????

[John]

Does anyone know for sure what the best way to deal with algae is?

The ideal situation is to never allow algae to form. So that creates a question about how to prevent its formation on a coach that may be stored for an extended period of time.

Once algae forms what is the way to get it out of the tank and fuel system? Algae can plug our fuel filters. Once it is in the fuel tank can it ever be completely removed?

I suspect there are a lot of opinions about algae and the best ways to prevent or deal with it.