Hi Folks,
I've seen a lot of tank reservoir issues on this and other Ranger forums. They don't make new Ranger reservoirs and our old ones are starting to go. I've come up with a solution that is fairly cheap and is frankly a better design than the original reservoir and switch. You will need to purchase a 1987-1997 F250 tank selector valve, four small hose clamps and 20 feet of 3/8" nylon fuel line. This solution should keep our classic dual tank Rangers on the road for decades to come. Follow the steps below:
1) Remove the six bed bolts and disconnect the rear lighting connectors. Remove the bed to expose the dual fuel tanks. Remove cross braces and shields so that you have access to the reservoir and selector valve.
2) Remove all four fuel lines from the old Ranger reservoir. Remove the reservoir.
3) The F250 tank selector has six hose connections. Like the Ranger reservoir two go towards the engine. However, the F250 selector valve/reservoir has four that face the tanks. Replace the old Ranger reservoir with the new F250 selector valve/reservoir by only connecting the line that feeds the high pressure pump and the return tube from the engine (the two engine side connectors that were previously connected to the old Ranger reservoir).
3) Disconnect all six fuel lines from the Ranger's fuel tank selector valve. You can remove the two fuel lines that used to run from the selector valve to the old reservoir. Do not remove the electrical connector from the selector valve.
4) Remove the feed and return lines from the front tank. Save these two lines.
5) Disconnect but don't remove the rear two rear tank fuel lines.
6) Slide the rear tank lines that were connected to the Ranger selector valve forward to the new F250 selector valve/reservoir and connect to the front tank inlet ports on the rear of the new reservoir. Connect the tank ends of the former rear lines to the front tank. Your front tank is now fully connected.
7) Carefully remove the four connectors from the front tank's fuel lines. I used a razor blade and was very careful not to nick the connectors. The feed lines are 3/8" connectors and the return lines are 5/16". I could not find new connectors.
8) Cut two lengths of 3/8" nylon fuel lines long enough to reach from the rear side of the new F250 selector valve/reservoir to the rear tank. Gently heat the end of the fuel lines with a hair dryer and slide over each connector. Ensure that you have a 3/8"connector on each side of one hose and 5/16" connector on each end of the second hose. Secure each end with a hose clamp.
9) Connect the new line with the 3/8" connector to the feed side of the rear tank inlet port to the new F250 selector valve/reservoir. Connect the 5/16" connector the remaining return inlet port on the new F250 selector valve/reservoir. Connect the other side of the two hoses to the rear tank. Your rear tank is now fully connected.
10) Turn on the engine and check for leaks. Switch the tank switch on the dash and again test for leaks.
11) Once you are certain that you have no leaks reinstall the braces and shields and reinstall the bed and rear light wiring.

Theory of operation: The Ranger reservoir has a check valve that fails over time. The Ranger reservoir and fuel line connectors are no longer available. The original design of the Ranger dual tank system relied on solenoids in the Ranger selector valve to switch gas that fed the reservoir and returned gas to the selected tank. The 1987-1997 F250 selector valve is built into the reservoir and it uses fuel flow to select the tank. When the front tank's pump is energized, fuel flows from the front tank through the selector valve and unused fuel flows back to the front tank. The rear tank is blocked. The opposite is true when the rear tank is selected. The F250 selector valve is larger than the original Ranger reservoir but it fits. The F250 reservoir uses the same size fittings as the ranger. The old Ranger selector valve will no longer be needed to route gas from the selected tank. It will however be needed to route the fuel level to the dash and energize the proper in-tank low pressure pump. All of the lines from the input to the high pressure pump near the front of the ranger are low pressure. I used screw type hose clamps. Choose clamps that provide pressure all the way around the barbed fitting.

Disclaimer: I made this modification to my Ranger and it works for me. I have switched tanks on the go and had no issues. There is no guarantee implied and I accept no responsibility for your safety. I first attempted to use fuel line splicers and they leaked. Using the original connectors with no splices prevented leaks. Verify that your connectors and the push in locks are in good shape. The F250 selector valve is available for around $50. The 3/8" nylon fuel line cost about $60 in 2025. The 3/8" fuel line fits very snuggly over the 3/8" and 5/16" connectors. You are working with fuel. Fuel will spill when you remove the lines. Avoid getting the fuel on you (especially in your ears). Do this work in an open ventilated area with no open flames. Temporarily plug the fuel tank barbs. Do not use the heat gun anywhere near gas fumes. If you have any reservations about performing this modification, take your truck to a professional.