My Td5 Defender already has 45l Frontrunner gravity tank installed.

75L (std def tank) plus 45L gives 120L , still not enough for our big trip

I bought a 50L BrownDavis aux tank from ebay, $295 which required a hole to be cut in the floor for the filler, I finished this off with a flat Marine screwcap fitting ($2.50 from BCF) .

The biggest pain with the existing Frontrunner aux tank inplace was finding somewhere to run the vent & transfer pump pipes from the new tank

The best solution was to cut the 2" rubber fill tube and add in a 2" section of exhaust pipe with a couple of 3/8 brass barbs silver soldered in. This did not quite allow the Td5 filler cap flange to go home so I mounted it on a 1/2" thick green kitchen chopping board cut to shape. Defendoor cover still fits, just.

I used a Marine fuel filter / water trap from BCF $45.00 including mount, the filter by chance is the same as a 1HZ oil filter cruiser so easily available if stuck. For a Transfer pump I used a new AC Delco 6.5L Chev Diesel lift pump $55.00 (ebay is great) .

170L all up should give us the range between fills that we are looking for, not bad for change out of $500

pics to help explain



frontrunner fill tube


modified fill tube




chopping board extension



brass barbs