Hey there Wombat - These threads have been merged
I see you want chassis mounting specific info however lets keep the simular questions about fuel filters on one thread.
Have you seen this thread?
http://www.newhilux.net/phpbb/viewtopic.php?f=29&t=18621Most pre-filter set ups are 30 micron - the OEM is said to be around 5-10micron so not much sense running anything under 20
1 - yes, pre filter is best if water is a concern. A pre-filter that has a water warning buzzer is a logical solution here. Even if you visually inspect the water trap every day it takes just seconds for water to get sucked into the bowl while driving. A water sensor with warning light/alarm will give you instant alert and possibly time to shut down before it gets into the OEM filter.
2 - Location is the main concern under the vehicle if you go off road. Those Donaldson pre filters look tall but you might find a spot where the bowl wint get smashed. Have heard of some guys thinking of Prado pre fuel filters but havnt seen where they install them and I doubt they have a water alarm. Some guys mount the 2nd filter on the driver side of the engine bay.
Someone else may have seen a under chassis filter