A.P: What are your thoughts on blowing an air filter out with an air hose at the local service station – good/bad or only when needed?

Allan: You haven’t really got much choice, but if you tap it on the ground a bit get most of the dirt out and then blow it from the inside out until you can’t see any more dust – that’s all you can do and I believe it will be adequate.

A.P: So  – take an extra spare filter (at least one), try to keep them as clean as possible, check them regularly, and try to avoid situations where you’re blocking it up.

Allan: Unless you want to talk about snorkels, the use of snorkels doubles the life of the motor in heavy dust conditions! If you watch a film of vehicles in convoy, the only thing protruding above the damaging dust is the snorkel head!

A.P: Wow, ok. This is a classic; leave the snorkel head on forwards or backwards?

Allan: Nah, turn it backwards if you’re in a convoy and turn it forwards if you’re on the highway or on your own.

A.P: Some people say turning it backwards causes a vacuum.

Allan: No, it doesn’t cause a vacuum to any extent (at off-road speeds). In any case it’s better to risk a vacuum than wear the motor out prematurely.

A.P: I have seen the sponge filters on top of a snorkel

Allan: You sure you haven’t seen a centrifugal filter that sits on top – they’re great-it’s a pre-filter

A.P: They’re better?

Allan: Centrifugal pre filters are a very good addition to any system. Correctly operating, they greatly increase the service life of the original air filter.

A.P: So that’s the cyclone Perspex one, there’ also a genuine hard plastic mushroom top.

Allan: With the filter in it or…

A.P: Yes.

Allan: Anything that brings rotary action to the air going in makes the heavy particles go to the outer sides and then the engine takes clean air from the centre. Very effective!