U320 fuel tank caps

Topic: U320 fuel tank caps (Read 1136 times) previous topic - next topic

U320 fuel tank caps

August 25, 2020, 11:06:37 pm

So today I removed the fuel tank to start fuel line replacement. There is fiberglass end caps that I believe were added to dress up and finish off the area. The tank cover on the coach left side could perform as a barrier for the batteries, however mine was not totally sealed and seemed there was no corrosion issues. So that being said is there any real reason for them. The tank would cool better if they were left off IMO. Also there is a small vent in the forward bulkhead about 20 inches off the bottom behind the front tires that is wide open and allows mud dobbers in. It also allowed a lot of road dirt in also. Concerned about collecting moisture and causing corrosion it lines up with the outer edge of the fuel tank. No caps would mean being able to see and clean before it gets to the tank. Any ideas too retain caps. Will cover vents with screen at the very least. Spray foam in the center section to prevent pests from travellng thru freely.
Scott

Re: U320 fuel tank caps

Reply #1 – August 25, 2020, 11:21:04 pm

I believe the covers are just for cosmetics. My coach didn't have that slot in the bottom curious why it is there. There has to be a reason to put it there. I thought about leaving my covers off as many pics on the forum show the aluminum tank without covers. The tank vents to the bottom so no fumes should get to the battery terminal. There has been discussions about vented or not vented caps, mine are not vented.

Re: U320 fuel tank caps

Reply #2 – August 25, 2020, 11:28:29 pm

But, a FUEL COOLER (aka transmission cooler repurposed) in the return line from the engine is the way to control fuel temperature.

Don't think removing the cosmetic covers will make 5 degrees difference.

Re: U320 fuel tank caps

Reply #3 – August 25, 2020, 11:42:18 pm

Brett my coach has a factory cooler. Chuck the vents are in the top part of the compartment with the battery venting out the bottom below them. The fuel caps on mine allow air to be drawn in but not to vent out. Checked just tonight. There is a vent on coach right on top going to a 1/4 inch line running forward past the bulkhead. Haven't seen how it's routed up front but am already curious on where/how it goes. I'm sure the forward vents are there to allow pass thru air flow past batteries and propane on right side.
Scott

Re: U320 fuel tank caps

Reply #4 – August 25, 2020, 11:49:41 pm

Quote from: dsd – August 25, 2020, 11:42:18 pm

Brett my coach has a factory cooler.
Scott

Then, fuel temperature should not be an issue.

Leave covers off/put then on as you desire.

Re: U320 fuel tank caps

Reply #5 – August 26, 2020, 12:08:22 am

The vent just hangs down in front of the bulkhead. My caps work the same as yours, air in, no fuel out.

Re: U320 fuel tank caps

Reply #6 – August 26, 2020, 12:14:21 am

A 40' has a bigger fuel tank. 400# pounds more weight. Seems panels were installed to beauty up the larger area in a 36'. same bay.

Re: U320 fuel tank caps

Reply #7 – August 26, 2020, 12:26:50 am

My 40' has the panels. Makes the compartment look clean.

Re: U320 fuel tank caps

Reply #8 – August 26, 2020, 12:41:38 am

My curb side is bare tank. Drivers side has a panel if memory serves me. Retains heat. High fuel temp killed my m11 ECU

Re: U320 fuel tank caps

Reply #9 – August 26, 2020, 01:19:09 am

So the fuel tank showed being 194 gallons. Was unaware the forties carried 400lbs more fuel. Nice

Re: U320 fuel tank caps

Reply #10 – August 26, 2020, 02:54:00 am

There is a lot of 36' U-320 coaches with that same fuel tank.

Mike

Re: U320 fuel tank caps

Reply #11 – August 26, 2020, 03:50:00 am

The spec sheet for my 36 foot U-320 says 194 gallons of fuel. When we exposed the tank to change out the fuel lines the tank was placarded as 201 gallons.

Richard

Re: U320 fuel tank caps

Reply #12 – August 26, 2020, 10:16:42 am

I didn't look at my decal so don't know if the ullage is the difference on the tank capacity. My International has both the capacity and the amount it would fill to on the tag.

Re: U320 fuel tank caps

Reply #13 – August 26, 2020, 10:40:31 am

Our U320 has a 194 gallon tank listed on the capacity page on the book, however, if you raise one side of the coach and lower the other, you can get more fuel in the tank. How much more is debatable! 194 is good for us!

Re: U320 fuel tank caps

Reply #14 – August 26, 2020, 12:15:06 pm

Mine has the same sticker. 201 probably includes expansion area. 194 gallons is enough for me. The tank size really grows when you are handling it. Picture in first post. I think I will remove the fiberglass caps or clearance the aft top for a viewing window. I really like being able to visually see the top of the tank and fuel lines. In looking at it closer all the dirt may be from the center area access. The fiberglass caps were inside of the vents behind the wheels diverting dirt towards the door. Dirt/silt In photo was inside of the fiberglass caps. I kinda think it came from the center access area? Center Access area will receive spray foam (orange fireblock rated) after lines are installed to prevent dirt, mud dobbers and mice from using it as a front door. Makes it a real pain to service in the future but prevents more than you loose IMO. It also limits that area contributing as a additional vent. Planning on screens over those two vents behind the wheels and possible a Louver on the wheel wheel sides to help divert dirt collection. Positive airflow a must for batteries and propane. Cause and effect
Scott

Re: U320 fuel tank caps

Reply #15 – August 26, 2020, 12:40:19 pm

The fiberglass covers for the central access overhead might pull the screws out if expansion foam was injected into that area. Post how yours works and if no problems I might follow.

Re: U320 fuel tank caps

Reply #16 – August 26, 2020, 01:46:39 pm

Chuck, I'm tanking about forward of the fuel tank in the bulkhead pass through area. Back side of front axle area. Haven't got to the rear yet. Still cleaning
Scott

Re: U320 fuel tank caps

Reply #17 – August 26, 2020, 02:20:43 pm

Quote from: dsd – August 26, 2020, 01:46:39 pm

Chuck, I'm tanking about forward of the fuel tank in the bulkhead pass through area. Back side of front axle area. Haven't got to the rear yet. Still cleaning
Scott

Good idea

Re: U320 fuel tank caps

Reply #18 – August 30, 2020, 12:07:12 pm

So in reading the fuel loose spilled post got me thinking that maybe there is a higher purpose than just being finishing trim. If sealed they would prevent fuel from ever going under the tank. Sounds like my 2001 U320 has plenty of vents and drains on both sides and the purposelessly provided fuel separation for overfilling. So I like the idea of preventing the fuel from going under the tanks but still dislike the covers. I think I'm going to compromise and leave the covers off but seal the bottom and sides of the tank with aerospace fuel tank sealer To prevent migration of fuel under tank. Glad I was in no rush to put fuel tank back in. Still need to seal and tape forward bulkhead Inside seam next to the tank. That was not previously completed on my coach. Fortunately no corrosion issues.
Scott

Re: U320 fuel tank caps

Reply #19 – August 30, 2020, 07:37:07 pm

Center access foamed. Plenty of room to pull lines thru in the future. No room for mice. There was abut a inch gap on top after setting since new. This should stop silt from passing thru as it had in the past. Installed pvc liner around open foam hole tank drain access. Removed trim ring that increased drain height by .035. This will allow all fluids to drain as much as possible. Taped both forward and rear walls with moisture barrier tape to prefent water from sneaking into structure. Backside of forward bulkhead repainted. Fuel tank going back in with both fiberglass caps installed to prevent fuel and water entering area in the future
Scott

Re: U320 fuel tank caps

Reply #20 – September 05, 2020, 02:53:08 pm

Fuel tank finally installed. After some thought about the fiberglass covers I believe Foretravel put them there for more than looks. They do separate the fueling areas from airflow to the next compartment. There are six 3 inch drain in both the propane and Battery storage areas. The only drain below the tank is the sump drain access and the tank closes it off fairly close. So covers back on and sealed up to prevent spilled fuel from going into or under fuel tank. Also prevents air migration to center bay.
Scott

Re: U320 fuel tank caps

Reply #21 – September 05, 2020, 03:42:57 pm

I will reseal my covers when weather permits, 118 here today and nothing under 100 listed for the next ten days. When I pulled the tank I only bolted the covers back on.

Re: U320 fuel tank caps

Reply #22 – September 05, 2020, 09:18:48 pm

At least around filler neck and lower say 2 inches. Originally they were sealed to the top, put see no reason too.
IMO Scott

Re: U320 fuel tank caps

Reply #23 – January 13, 2025, 09:01:14 pm

Quote from: dsd – August 25, 2020, 11:42:18 pm

Brett my coach has a factory cooler. Chuck the vents are in the top part of the compartment with the battery venting out the bottom below them. The fuel caps on mine allow air to be drawn in but not to vent out. Checked just tonight. There is a vent on coach right on top going to a 1/4 inch line running forward past the bulkhead. Haven't seen how it's routed up front but am already curious on where/how it goes. I'm sure the forward vents are there to allow pass thru air flow past batteries and propane on right side.
Scott

Scott, do you have images of the factory fuel cooler installed?

Affiliate Notice