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- #21
Everyone above is correct. A previous owner did change out the fuel tank to a pre-74. Last week I removed the fuel tank, cleaned it, rust protected the exterior, and replaced all hoses. Each of the four corner vent hoses runs directly into the driver side evaporator.
There is no return fuel line back from the carburetor. As it does appear that the carburetor was replaced with a weber. That hard line underneath the truck is capped.
This afternoon when I got home the car was sitting in the driveway and gas was pouring out the gas tank. It was maybe 82° here at home and the car had not been moved or started all day.
When I arrived home I removed the evaporator from the rear and blocked off each hole in succession to ensure the evaporator wasn’t clogged. It is not. I also blew air from the vent hose that runs from the back to the front and air came out the front. I also rechecked the canister by blowing air in one nipple on the top air came out the other. I also tried that the opposite direction and it was also clear.
I checked the check valve that sits at the rear and with heavy pressure it does open, I have currently remove that indirect plumbed the vent hose from the evaporator directly to the front without the check valve.
I locked the gas tank cap back on and currently it has not overpressured in leaked. I wonder if it is possible that the check valve is requiring too much pressure to be released therefore forcing the gas after building pressure to take The path of least resistance pushing gas up the filler neck and out the cap.
I also did some reading that stated that if there’s any of the four corner vent lines have any sagging them they may create a P-trap affect begas moving into the curve therefore blocking air From escaping. Again not allowing the air to get out causing the gas to move up the filler neck when pressure is too high.
My current plan is to leave the check valve out. Why do we need it anyway? If pressure is high would we rather at freely move up to the front of the vehicle so we can be expelled? In addition I’m gonna order a new gas cap for the better seal. If anyone knows of one that will work for us 74 55 That has the ability to vent I would really appreciate the tip. I will slowly rule things out and I’ll let everybody know how it goes
Last thing I would ask that for those people who do change to a Weber carburetor where on the tank do they run a return line too? The only connections on this tank are the four vent hoses, two filler neck overflow hoses or filler hose, and the supply line to the carburetor to run the vehicle.
There is no return fuel line back from the carburetor. As it does appear that the carburetor was replaced with a weber. That hard line underneath the truck is capped.
This afternoon when I got home the car was sitting in the driveway and gas was pouring out the gas tank. It was maybe 82° here at home and the car had not been moved or started all day.
When I arrived home I removed the evaporator from the rear and blocked off each hole in succession to ensure the evaporator wasn’t clogged. It is not. I also blew air from the vent hose that runs from the back to the front and air came out the front. I also rechecked the canister by blowing air in one nipple on the top air came out the other. I also tried that the opposite direction and it was also clear.
I checked the check valve that sits at the rear and with heavy pressure it does open, I have currently remove that indirect plumbed the vent hose from the evaporator directly to the front without the check valve.
I locked the gas tank cap back on and currently it has not overpressured in leaked. I wonder if it is possible that the check valve is requiring too much pressure to be released therefore forcing the gas after building pressure to take The path of least resistance pushing gas up the filler neck and out the cap.
I also did some reading that stated that if there’s any of the four corner vent lines have any sagging them they may create a P-trap affect begas moving into the curve therefore blocking air From escaping. Again not allowing the air to get out causing the gas to move up the filler neck when pressure is too high.
My current plan is to leave the check valve out. Why do we need it anyway? If pressure is high would we rather at freely move up to the front of the vehicle so we can be expelled? In addition I’m gonna order a new gas cap for the better seal. If anyone knows of one that will work for us 74 55 That has the ability to vent I would really appreciate the tip. I will slowly rule things out and I’ll let everybody know how it goes
Last thing I would ask that for those people who do change to a Weber carburetor where on the tank do they run a return line too? The only connections on this tank are the four vent hoses, two filler neck overflow hoses or filler hose, and the supply line to the carburetor to run the vehicle.