Thread: Donaldson dual filter

The inner filter is primary as a emergency back up, I run without this though as if your engine is turboed with mods then it won't allow enough air flow, an will pop the indicator.

No way would I be without the inner!. The outer has a shelf life (two years from memory) and should have a date on it. I believe this only applies if the filter is not used. The original assembly purchased from Land Rover, which I installed after fitting the 4BD1T; was 4 years old!. I reckon it was the time-ex filter and the pre-cleaner that caused the sensor to show the filter element as being full. Replaced both, now she runs perfect.......any doubt, call them:

Donaldson Australasia Pty Ltd
P.O. Box 153
Wyong NSW 2259
Ph: 02 4350 2000
Fax: 02 4351 2036

Donaldson Filtration Solutions

Want more performance?, adjust your fuel, don't risk injesting matter into your engine........

if your going to run the engine do not do so without the inner... NEVER, under no circumstances... IF i hear of people doing it I will come and steal your suzie's and replace them with petrol engines probabley from nissans or even 2 stroke mopeds......

Bad people... how would you like it IF i stuck your mouth and nostrils into a bog hole of bulldust and held you there till you tried to breath....

ok rant over heres how your filter setup works and what the parts do


the outer is the secondary filter, to use my anology above thats the one that filters all the gravel out before it gets chance to clog the primary filter

The inner is the primary filter and its responsable for getting everything that slips past the secondary filter (including parts of the secondary filter) before it gets into your engine. in my anology that removes the dust.

and theres 2 stages of filtration before the air even gets that far the first is the intake grill which takes out leaves, bits of tree and lesser vehicles that get too close and the second is the "cyclonic" action of the air through the filter chamber and cather witch take out the heavy particals and most of the moisture from rain or light (and I mean light) splashing.

the second stage of "pre filtering" in theory at higher engine speeds is almost as effecient as the normal secondary filter but is let down slightly in the rover application by the orientation of the filter.

the primary filter has a usage life of 2 years, at the 5th clean out of the secondary filter or if cleaning/replacing the secondary filter does not allow operation without tripping the blocked filter sensor. whichever comes first. The filtering elements as supplied should be in a plastic bag when new and have no "shelf life" providing that the plastic is undamaged and the dessicating pack (if included) is still dry.

The inner filter has no more filtering capacity than the outer. What will pass through the outer will pass through the inner. The inner filter has two purposes. In the case of rough usage (logging, earth moving) where the filter housing is externally mounted and liable to damage that may pierce the outer filter then the engine will not be exposed to dust damage as long as the inner filter is intact. The other purpose is in the case of continuously running engines (gen. sets, pumps) the outer filter may be removed for service whilst the plant remains in operation with the inner filter in place. A dual element filter in the case of the LR county is somewhat of an overkill as the outer filter is most unlikely to be damaged tucked away as it is high up behind the engine and under the bonnet.

what Brian said.

To add to Brian's comments - I have had one case where a relative borrowed the County for a trip round Australia - and the nut holding the main element came loose (?vibration from the Isuzu), allowing dusty air through - to be trapped by the guard element. So I don't think the second element is overkill!

John

Just as Brian said. The only time I've seen the inner with any amount of dirt on it was when a similar thing happened as with johns. And even in that case it could be blamed on the muppet arms that tightened the outer filter up.

The instructions for my tractors' filters state that the outer can be cleaned (by various methods) but the inner must not be cleaned.