Gas tank fillup

Topic: Gas tank fillup (Read 884 times) previous topic - next topic

Gas tank fillup

June 05, 2020, 09:10:42 am

Dumb question. Are there two separate fuel tanks. When I fill up it's around 90;gal. Do I have to fill both up separately.

Re: Gas tank fillup

Reply #1 – June 05, 2020, 09:15:21 am

NO
It is a handy feature when Fuel pumps are difficult to get to...
Safe Travela
Dave

Re: Gas tank fillup

Reply #2 – June 05, 2020, 09:20:35 am

One tank, two fills.

Do NOT fill from both sides at the same time unless EXTREMELY careful. One side will be slightly lower than the other and fuel could run out that side while the "high side" pump does not cut off!

Re: Gas tank fillup

Reply #3 – June 05, 2020, 09:23:56 am

Thanks

Re: Gas tank fillup

Reply #4 – June 05, 2020, 09:31:41 am

Brett is spot on. Been on the receiving end of the lower tank fill. Quite exciting. Lol. Also a equality important reason is the pump Dollar amount goes up slower with one fill hose being used. Just makes it feel like your getting your monies worth taking a extra three minutes to fill. One hundred, two hundred, three hundred, stop, is there no end. Fuel card takes some of the bite out of the cost. Thank you Rudy.
Scott

Re: Gas tank fillup

Reply #5 – June 05, 2020, 09:38:30 am

Also, when you have filled from both sides it's a real good idea to put both fuel caps back on before taking off. Takes a long time for that diesel smell to dissipate!
jor

Re: Gas tank fillup

Reply #6 – June 05, 2020, 09:39:49 am

Rick & MJ,

Count yer blessings. We poor Unihome owners can only fill from one side, and (at truck stops) it is the WRONG side.

At truck stops, I have to turn on the master pump, lay the nozzle on the ground, then fill up with the slave hose on passenger side.

I worried, at first, that the truck drivers might think I was acting strange. No worries - they don't pay the slightest attention to me.

Re: Gas tank fillup

Reply #7 – June 05, 2020, 09:55:43 am

Also, worth noting (in the specs sheet linked below) that your '98 U320 has a generous 194 gallon fuel tank.

Your 90 gallon fill-up only represents about half your total (useable) fuel capacity.

BUT, you are wise to fill up when half empty. The fuel in the tank will get very hot after several hours driving at high speed. The less fuel in the tank - the hotter it gets. You are doing your engine and fuel system a favor by filling up "early".

1998 Foretravel U320 Specifications

Re: Gas tank fillup

Reply #8 – June 05, 2020, 12:35:14 pm

Didn't know about the heat buildup. Thanks. At $2.00 a gallon, not painful

Re: Gas tank fillup

Reply #9 – June 05, 2020, 01:22:29 pm

Put your hand on the fuel tank on a hot day when you have been driving for a few hours, particularly if less than 1/2 tank. HOT.

Diesel fuel is used to cool and lubricate fuel injection components and then returns to the tank.

Some of us, early on installed "fuel coolers" (basically repurposed transmission coolers) in the fuel return line. Foretravel started fitting them as OE after that.

Re: Gas tank fillup

Reply #10 – June 05, 2020, 02:10:15 pm

I level the coach first then turn off the hwh panel then quickly turn it back on with the motor at high idle then raise the curbside of the coach a bit to make sure I can fill the tank full.

Shuts off. Restart at a lower fill rate.

Why? I find the exact amount should match the VPMS engine data plus the gen hours at .44gph and aquahot use.

If it does not something is wrong.

Not having a fuel cooler that Brett just mentioned taught me not to do this exact fill and then rocket up a long grade..

Fuel expands. Pushes out of the overflow.

Re: Gas tank fillup

Reply #11 – June 05, 2020, 02:50:42 pm

Your aftermarket monitor may give fuel temperature from the ECU. Each model of injection pump and engine brand has a maximum fuel temperature. As Brett says, less than a half tank on a hot day can indeed, burn your hand. A full tank has more area to radiate the heat but is in an enclosed space with not much ventilation.

Pierce

Re: Gas tank fillup

Reply #12 – June 05, 2020, 02:56:40 pm

Brett where do they install the fuel cooler? Any info is helpful. Pictures? Model number?

Re: Gas tank fillup

Reply #13 – June 05, 2020, 04:55:37 pm

Installation will certainly vary by engine, but here is the basic routing/what I did:

Buy Hayden transmission cooler-- larger the engine, larger the cooler. I can look up the one for the Caterpillar 3116 or Mike can take a picture of it.

Remove the fuel return line from the engine. It will be attached to "fuel cooler OUT" line back to tank. May need an extension-- depends of specifics.

New fuel line engine "fuel out" to new cooler.

I located the cooler outermost in the air flow so: fuel cooler, CAC, radiator.

And, that is how later-model Foretravels are plumbed from the factory.

Dianne also made an easy to install canvas cover that velcroed over it for use in cold conditions so it would not over-cool the fuel. Put that on in late fall, removed in spring.

This is much more important in Foretravels than other coaches as the fuel tank is not external where it can be cooled by outside air.

Re: Gas tank fillup

Reply #14 – June 05, 2020, 05:20:25 pm

Thanks

Re: Gas tank fillup

Reply #15 – June 05, 2020, 05:49:27 pm

Unless the day's travel was pretty short, I generally fill the tank just before going to the campground. My VMSpc shows fuel temperature. First thing in the morning it is pretty close to ambient air temperature. It slowly rises during the day. When I put 40 gallons of fuel in it drops quite a bit.

The reason I fuel as I do is to reduce the amount of water vapor that condenses in the fuel tank overnight. Today the fuel temperature was 107 when I started fueling and 90 afterward. I suppose that temperature decrease might have added a drop or two of water to the fuel, but probably not much more than that. If I hadn't gotten fuel, with the low predicted to be about 60 tonight, I'm guessing that I'd have more than a drop or two of water added to the tank. (More air space = more condensation.)

Re: Gas tank fillup

Reply #16 – June 05, 2020, 06:00:13 pm

Yes condensation is a definite reason to fill the tank.

Re: Gas tank fillup

Reply #17 – June 05, 2020, 06:25:18 pm

What year did Foretravel put in the fuel coolers?

Re: Gas tank fillup

Reply #18 – June 05, 2020, 08:16:14 pm

Quote from: oldguy – June 05, 2020, 06:25:18 pm

What year did Foretravel put in the fuel coolers?

My '99 has it so yours should too. Look in the grill at the radiator and the small cooler on the outside of the CAC is the fuel cooler.

Re: Gas tank fillup

Reply #19 – June 05, 2020, 09:09:38 pm

Thanks it's good to know and I will check on it. Thanks

Re: Gas tank fillup

Reply #20 – June 05, 2020, 10:03:36 pm

Quote from: kb0zke – June 05, 2020, 05:49:27 pm

Unless the day's travel was pretty short, I generally fill the tank just before going to the campground. My VMSpc shows fuel temperature. First thing in the morning it is pretty close to ambient air temperature. It slowly rises during the day. When I put 40 gallons of fuel in it drops quite a bit.

The reason I fuel as I do is to reduce the amount of water vapor that condenses in the fuel tank overnight. Today the fuel temperature was 107 when I started fueling and 90 afterward. I suppose that temperature decrease might have added a drop or two of water to the fuel, but probably not much more than that. If I hadn't gotten fuel, with the low predicted to be about 60 tonight, I'm guessing that I'd have more than a drop or two of water added to the tank. (More air space = more condensation.)

Thanks David, I didn't know about the fuel temp reading.

Re: Gas tank fillup

Reply #21 – June 05, 2020, 11:51:05 pm

Our tank has a pressure cap on the fill and does not seem to suck any air at night. On most trips even in the Sierras, we go through Navada for quite a few miles where diesel is usually about a dollar a gallon less expensive so unless going down the Sacramento Valley, we don't fuel that often in California so our tank is almost always down a ways at home. No algae so far in the coach but several times in the car and tractor.

Fuel gets pretty hot on trips and a cooler is on the "to do list." Have the cooler, just have to find the time to install it.

Pierce

Re: Gas tank fillup

Reply #22 – June 06, 2020, 08:15:00 am

Quote from: Pierce & Gaylie Stewart – June 05, 2020, 11:51:05 pm

Our tank has a pressure cap on the fill and does not seem to suck any air at night.

Your fuel tank must be vented to atmosphere in some way. Wouldn't work very well otherwise...

Re: Gas tank fillup

Reply #23 – June 08, 2020, 04:28:01 pm

Quote from: Pierce & Gaylie Stewart – June 05, 2020, 11:51:05 pm

Fuel gets pretty hot on trips and a cooler is on the "to do list." Have the cooler, just have to find the time to install it.

Take pics when you put it in. I'm planning the same thing. My problem is finding a good place to tap in to the return fuel line.

see ya
ken

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