Vehicle engines run best on cool clean air and in most vehicles the air intake is located lower say behind the grill or through the inner guard of the bonnet of the vehicle. Lower air intake areas are more susceptible to dust and although the air filter will trap most of the dust the filter will need regular changing or cleaning to maintain good engine performance.
Popular 4WD and RV destinations may require you to cross over streams and rivers. If water is sucked through the air filter and into the vehicle engine it can cause a hydraulic lock. Only a small amount of water ingested into a diesel engine, which has a high compression of about 20:1, can cause it to lock and cause major damage. A petrol engine has a lower compression of about 10:1 but water can still cause serious damage.
Snorkels are designed to collect air from the top or air ram through to the air cleaner or air filter thus providing cool clean compressed or denser air for smooth engine performance. Vehicle snorkels are made from polyethylene, are heat resistance and UV ray resistant, have stainless steel and plated hardware for corrosive resistance as well as a unique evacuation system to disperse rain and unwanted moisture. Some snorkels are also compatible for an optional precleaner.
A hole is cut in the vehicle fender or front guard to allow access to the air filter and the snorkel is bolted to the A pillar of the vehicle. All connecting hoses should be air-tight.
The Safari snorkel air ram can be rotated to prevent dust ingress, say when travelling in a 4WD tag along tour or convoy, as well as when driving in heavy rain and snow. The air ram should be rotated back to the forward position for normal driving as having it rotated backward can reduce performance.
Safari Snorkel 7” or 10” Pre-Cleaner replaces the air ram head on Safari Snorkels and as air enters the round clear perspex chamber the dust particles are separated by centrifugal force. The dirt then settles in the bottom of the outside chamber before it reaches your air filter.
Donaldson TopSpin Pre-Cleaner can be fitted to vehicle snorkels are also an alternative in dusty situations. This filter/pre-cleaner increases the life of the vehicle’s air filter by ejecting dust particles before they reach the air filter.
Uni Filter Australia supply a one size fits all Snorkel Ram Head Cover which they state provides a locust barrier and additional protection when in a 4WD convoy. Uni Filter also supply a “Droopie” Snorkel Pre-Cleaner, a sock like sleeve that drops down from ram inside the snorkel, which they state does not affect air flow and removes 90% of dust before it reaches the main filter. However, the Snorkel Pre Cleaner Service Instruction on their website contains the ‘Warning: Unifilter’s snorkel pre-cleaners are not suitable for highway use. We recommend use only in dusty conditions”. Uni Filter Australia also supply a washable dual layer foam air filter coated with a special blend of oil to filter out the dust.
If your vehicle is a turbo diesel, you may want talk to a specialist before using oil coated pre-cleaners as they are coated in oil to collect the dust and too much oil can be sucked into the turbo and may cause problems.
Toyota supply an after-market snorkel for most of their 4WD vehicles. The Toyota Genuine Air Filters have a triple layer filtering element which has a series of different gauge meshes such as course, medium and fine to trap different size particles. Toyota also manufacture a washable air filter or reusable air filter so if you have two you can swap over the spare and clean and wash the other out later.
Popular brands of snorkels are Safari Snorkels, Airtec Snorkels and Airflow Snorkel Kits .
Where Can I Get A Vehicle Snorkel?
Vehicle snorkels are usually an aftermarket accessory and are available from Safari Snorkels, TJM, ARB, Opposite Lock and other 4WD accessory stores and eBay.
Step by step instructions on the installation of vehicle snorkels are available from some manufacturer’s and supplier’s websites.
Vehicle Water Crossing Cover Or Water Bra
Water crossing bras or water crossing covers strap over the front of your vehicle’s grill to prevent the water being forced under pressure through the vehicle’s ‘grill’. If this forced water gets caught up in the radiator fan, the fan blades can put a hole in the radiator.
A snorkel is also essential to allow the engine to breathe above the water level.
To avoid radiator damage, strap a tarp or fit a vehicle water blind/water crossing cover (water bra) across the front of the bonnet when crossing a river or creek, with some depth, in your 4WD.
There are marine grade heavy duty, PVC backed water crossing covers that attach to the vehicle’s side rear view mirror mounts. Three large gills at the base of the water crossing bra allow water to drain away after the crossing. The front of the water crossing cover also has a built-in snatch strap pouch and will conform to any vehicle shape including those with winches and antennas.
The ARB Water Crossing Cover is made from Nylon material and has elasticised edges to help it fit to the shape of the vehicle, long restraining straps to secure it to the side mirrors, clear PVC inserts for the headlights and can be fitted by one person.
MSA 4 x 4 Accessories (previously Michelle Sacs) make a product called a water crossing bra made from 420 Denier, PVC backed Nylon for maximum strength and this is available from them or 4WD after market suppliers such as TJM, Opposite Lock, BTA 4WD Centre and Mannell Motors.
Differential (Diff) Breathers
When attempting a creek or river crossing it is best to stop for a while to allow the differential to cool. Differentials have a breather to equalize the pressure in the axle as the temperature in the axle changes. The stock breather is a vent to the outside air with a cap over it to prevent debris and water. When crossing creeks and the axle is submerged in cool water the temperature in the axle and the diff housing changes so when the axle is under water the change in pressure can pull water into the axle housing.
For those of you with some mechanical ability, extending the diff breather may be a relatively easy job. You can do this by removing one of your diff breathers (these are a little plug screwed into the top of the differential), take the diff breather to someone who can make you up a hose fitting with the same thread as the breather. Purchase some transmission cooler hose (as this type of hose is manufactured to be fuel and oil resistant) to suit the fitting as well as some small cable ties or electrical ties and then replace the factory breathers with the new fittings, run the hose to a high position under the bonnet keeping it away from heat. Make sure you run the hose high to the top of the firewall and where it will not be subjected to impact. Leave enough slack in the hose for any diff drop and ensure the hose is positioned so there will be no cramping of the hose. Another option, suggested on a 4WD forum, was to cut the hose endfitting (not the diff end) and buy 2 double ended barbs to fit inside the diameter of the diff hose. Then insert one end of the double ended barb into the hose still attached to the diff and insert the extension hose onto the other end of the barb. Use clamps to make sure the hose or breather lines don’t separate. The opinion on some forums is a filter is not required for the end of the diff breather hose but some have attached a lawn mower petrol filter to keep out dust.
Even when adding extended diff breathers it is still considered necessary to allow time for the diff to cool down before a creek crossing as there is no guarantee water will not enter the diff with a sudden reduction in air pressure.
ARB supply a Differential Breather Kit designed to provide a high flow, zero back pressure, zero vacuum breather system to keep the drivetrain free of water.
Kits are available to extend the diff breathers higher up the chassis by using plastic tubing. Diff breather kits are available from 4WD accessory stores and eBay.
There is also a product called Creeper Breather – Differential breather kit. This kit includes a bellows, a housing fitting and clamp. The Creeper Breather fits all Toyota Pick Up / 4Runner solid axle housings (front and rear). Available from Trail-Gear.com or one of their distributors.