I have recently got my self a 91 Brumby, it has some issues that I am working through. I have replaced the fuel filter under the bonnet  but I have found a second one under the car near the fuel tank. I am having trouble finding a listing for it at any of the parts retailers here in Australia. I am going to take it out and get one to match but my question is why do they have 2 filters. The one under the bonnet has three lines going to it and the one under the car has two.

Just curious as to why there are two filters.

I have often wondered the same, as my 1984 GL wagon is like that. I have just under 200,000 miles on mine and I haven't checked on a replacement but I expect to purchase one as soon as affordable. I haven't checked, but some of us use RockAuto for parts and I have had good experiences with them though all parts are not available. Try http://www.rockauto.com/   . Best of luck to you.

The rear filter is a Ryco Z427 or equivalent. SCA or similar will be able to get one in for you in a few days.

The front is a Z366.

The rear is a dedicated filter, the front is a fuel/vapour seperator.