Purchased the coach used with 13,000 miles in excellent condition. Was advised when I purchased the coach that it would only take fuel very very slowly. ( Can't even get fuel lever on nozzle to the first latch position without it kicking off.) Takes about 30 minutes to fill the tank. Previous owner said that he originally had a problem with the Gen Set cutting out at 3/4 of a tank of fuel. He took it to an rv dealer who fixed the problem by dropping the tank and adjusting the position of the fuel pick up tube which is in the fill pipe.
This fixed the Gen Set problem but not the slow fill problem. My mechanic dropped the tank and felt that with all the plumbing in the fill pipe for the gen set was the problem so we installed another pick up tube elsewhere in the tank. Didn't fix the slow fill problem. The only way we can get it to take fuel up to this point is to vent the tank to atmosphere and break the seal from the nozzle to the fill pipe. by pulling back on the rubber portion of the fuel nozzle. Forrest River says they have never heard of such a problem however all the plumbing is the way it came from the factory.
It is obviously a venting problem but can't vent to the atmosphere as this will call an emissions light. Any ideas please email me at firstname.lastname@example.org