Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 13, 2025 ...

Must be vented

If you fill the tank FULL by tipping the coach then drive up the grapevine in Lebec, ca full throttle hard the expansion of the hot fuel caused a solid stream of fuel out of the tank vent hose.  Second time it happened.

First time was down a dozen gallons from non tilted full.

I cracked the fuel cap on the second event after I stopped and the fuel pouring out stopped. 

Replaced both caps with vented.

Have not had another leak yet.

Full tanks and twisty roads can have a fuel smell if i am hard on the turns.

What's everyone else using?

Would still like to confirm cap # before I order them.

Our U300 has a non-vented cap. Gives a big poof when removing while fueling on the road.

Pierce

You could try calling the FOT parts desk and see what fuel cap they sell...should be able to give you a part number.

Chris,  are you near a parts store that they can match it up?  We're in NH right now and only a few feet from a NAPA store.  If you want I can take one of mine there and have them match it.

Non-vented here also.

You guys probably drive nice.  On twisty roads in the local mountains the vented caps will smell if the tanks slosh a lot.

Totally Full tank and a long hard full revs run the expansion of the hot fuel caused an overflow twice.

If I slant the coach to absolutely fill the tank the engines mpg plus the gen run hours and with no aquahot use exactly match.

That's my way of verifying nothing has changed or is leaking or bad.

I am rentitive about the details.

Normal fill leaves maybe 5-8 gallons missing if I leveled the coach first before filling up.

Normal roads no issues.  Full power banzai run up the grapevine after filling up at Lebec and 75 degrees ambient caused the overflow.

That no one else has experienced this is actually not surprising. 

Every used diesel rv I ever have driven  was not really broken in.  Babied.

As usual my driving these shows things most never see. 

Once with one gallon down and once with a dozen down from full I pulled canon pass and grapevine at full throttle full revs and the heated fuel expanded enough with the nose up the 6% grade to overflow the tank.

Tank was hot to the touch. 

You are over a few lanes from me and in no hurry.

I enjoy driving these harder than most.  Judging by results.

I need another set of caps.  Vented and non vented. 

Level your coaches when filling then turn off the leveling for a second with the motor running at fast idle then restart the leveling panel then raise the curb side quite a bit and shut everything off.

Now fill the coach.  When the filler cuts off pull it back until it's barely in the tank and restart the filler at a lower pressure.

Sometimes several times.  Now it's really full.

 Non vented caps and a long hard 6% grade pull floored and at max revs and a m11's heat input to the returned fuel will cause an overflow.

Like I said I was always testing the limits.  Not hurt it.  Just use it.

Mountain roads around big bear area can generate fuel smells if I am enjoying the engines torque off the corners.

No one else has experienced this?  Non vented caps and conservative driving and non full tanks would probably never show anything unusual

Took original Gunk(kerosene) to rinse the under Coach front area then a pressure sprayer to wash off the fuel and smell

Share the cap number when you get it please Chris.