Assuming yours is a diesel automatic, here's the schematic -
http://lushprojects.com/bongopartsmk2/c ... mgno=.html
Just about any parts can be obtained through a half decent Mazda dealer or any of the Bongo specialist garages, ie Allans, Bellhill, AVA, etc, you'll need the vin number to verify the right parts & it may take a month or two.
You could get one from a scrapper, not a high demand part, so there should be a few around, you'll need to specify age, engine type, gearbox type.
Alternatively, it is just a metal pipe, which should either be repairable, or someone should be able to make one up, replace with a length of oil resistant hose of the right size.
You can't polish a turd - but you can roll it in glitter.
