Dual diesel tanks

[White rhino]

Hi all, i have a 97' defender 110 Tdi. my vehicle has two diesel tanks. it has a lever to switch from one to another. i have several questions about this two tank set up and its not aftermarket. one time the passenger moved by mistake the lever to the reserve tank and fuel was transfered. was this just an oops or it does really transfer diesel from either tank? i have noticed that the main tank stays full while the reserve tank goes low eventhough i have the lever to use the main tank; diesel went from the reserve to the main tank. If someone know how this two tank set up works please inform me.thanks in advance.

[sparkstruk]

Hi,

Have you solved this yet? I had a similar problem with the changeover tap on my 96 300tdi. The switch over lever actually controls two taps - one next to the front tank and one ahead of the rear tank. The taps do two things - they open and close a line leading to the engine, and they open and close the return line. What my changeover switch was doing was switching the line feeding diesel to the engine, but the return line wasn't changing over and was feeding fuel back to the rear tank. It sounds like yours is doing the same - i.e. when running from the front tank it is quite rapidly draining that tank and filling the rear tank. It is not supposed to do this. I had to take the floor out in front of the rear seats to access the rear changeover valve as well as the front one. I stripped and cleaned both of these and after reassembly it has been working beautifully....

Peter

[White rhino]

Hi, I just came backfrom a 5 day expedition with my truck. And it does transfer diesel from the auxiliary tank to the main rear tank. And like u said, it should not do this. After u cleaned it, it did not transfer diesel? thanks.