What are Catch Cans and Pre Filters and why do I need them?

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Your SUV is generally your most expensive asset – after your house – so why wouldn’t you do whatever you can to keep it running at peak performance?

One of the first things we at TJM recommend to our customers is the installation of a Catch Can and a pre-filter kit. Here’s why…

Keep it clean

You may think that fuel contamination only happens in rural areas where’s an abundance of dirt and dust and fuel needs to be transported long distances. Think again! Every-day normal running of your vehicle can expose you to dust contaminants and fluctuating temperatures can also increase the likelihood of condensation and water in your fuel lines. This can be disastrous for your fuel injection system as water can cause corrosion and dust and dirt can cause abrasive damage and eventually leading to leakage and failure.


That’s where a fuel pre-filter comes in.

A pre-filter is installed between the fuel tank and the vehicle’s fuel filter to remove the majority of water and particle contaminants from your fuel.

Fuel passes through the filtration system in the unit which is made from ‘aqua-phobic’ material – in other words, the fuel can pass through, but the water gets repelled – then the water and particles gather at the bottom of the unit where it is collected and then drained.

Clean fuel = a happy vehicle and a happy owner.

The Black Scourge

Thick black carbon buildup inside a motor without a catch can

In the normal running of your vehicle, some oil, fuel and even water escapes the motor and ends up in the crankcase where it gets fed back into the motor to be burnt in the combustion process – this is known as blow-by gas. This doesn’t sound like too much of an issue, but the resulting gas has carbon residue floating in it, similar to exhaust gas. When this mixes with an oil mist, it forms  a sticky, black mess that clings to anything and everything! Additionally, oil that gets through can coat the pipework of your intercooler. Left unmaintained, your engine can end up sluggish and suffering from poor fuel economy.

Catch cans or oil separators are efficient methods of cleaning the blow by gas, before it gets re-circulated through your motor, and can significantly reduce the build up of oil and carbon in your motor. The device is installed between your vehicle’s crankcase and positive crankcase ventilation (PCV) line and redirects the blow by gas through a filter. The oil is separated from the gas in the filtration process and clean air is fed back through the motor.

How much oil could it catch?

The amount of oil varies depending on the condition of your motor; but, over 10,000km, it could be anywhere between 50 and 300 millilitres. That’s a considerable amount that you’re stopping from circulating through your motor … where it shouldn’t be.

How much does it cost?

The Direction Plus® Pre Line Plus Fuel Filter

The Direction Plus® Provent Oil Separator (catch can).

We recommend and install Direction Plus Pre-line Plus Pre-Filters which boast a filtration rate of 100% of water and 93% particle separation (as small as 300 microns for droplets and particles). It also has a great visual and audible warning system that alerts you when water is collected and so you know when to empty it! Emptying the water is as simple as turning a tap. Supply and installation of a Direction Plus Pre-line Plus Pre-Filter starts from $290 for a FM801DPK  plus installation*.

A catch can or oil separator is the perfect partner to this (but either can be installed by themselves) and we recommend the Direction Plus Provent Oil Separator. This system is the only one on the market with a ‘dedicated and proven oil separation element’, which means far greater efficacy and reliability. A Provent Oil Separator starts at $324 for a PV200DPK plus installation*.

What it boils down to is this …

… keeping your motor clean by installing a fuel pre-filter and catch-can/oil separator means it runs better and more efficiently AND will save you money in the long run!

*Kit and installation prices will vary from model to model and depending on individual vehicle models and any modifications. Please call us with your specific setup for a quote.

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Related Products

Direction Plus Preline Plus pre-filter

Pre filters keep your fuel lines clean

Direction Plus Provent Oil Separator (catch can)

Catch cans collect oil, fuel and water to keep your motor clean and running efficiently

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