Water Crossings; 15 ways to avoid drowning your 4WD

Drowning your 4WD can be one of the most expensive mistakes you will ever make off road. Once you get water inside your vehicle, you are in for a huge job cleaning it, and that’s if you get lucky. If you are unlucky, water can cause substantial damage and result in uneconomical repair via electrical and trim damage, future corrosion or a hydro-locked engine. 

It only takes 30ml of water to be sucked into your engine to cause permanent, serious damage to your 4WD. If you are lucky and the engine survives, you’ve still got a massive job cleaning the carpets, seats, 4WD drawer systems and your trim. Believe me, its not fun!

So, how do you keep the water out of your 4WD, and avoid drowning it?

Is there another way around?

In many cases, 4WD’s are drowned because people choose to drive through a water crossing, instead of taking an easy track to one side. A perfect example of this is at the Mundaring Powerlines Track near Perth, where people regularly drown their 4WD’s in huge mud runs that are over a metre deep with extremely steep entrances and exits.

Instead of driving on the solid, dry ground to one side, they take a chance and plunge into a huge pool of water, and often get stuck. If you want to avoid drowning your 4WD, stay out of the big water crossings if possible!

Walk the crossing first

When it comes to water crossings, the biggest mistake people make is not taking the time to get our of their vehicle and walk the crossing. Whilst it isn’t practical or comfortable to stop at every crossing, is it really worth the risk?

I’ll be honest here; I have driven through plenty of water crossings without walking them. I’ve also had the unfortunate displeasure of coming to an abrupt stop in over a metre of water near Lake Jasper, with both lockers on, correct tyre pressures no recovery straps in place. All because I didn’t take the time to walk the crossing.

Needless to say, I had a few minutes to sit and reflect on my poor decision, as my 80 series Land Cruiser slowly filled with water!

From that moment on, I’ll never go through anything that looks even remotely suspicious without either walking it, seeing someone else drive through it or at the very least poking it with a stick from the side!

Exceptions

It would take all day to do most 4WD tracks in the wet if you stopped at every single puddle of water, so there are some exceptions to the rule:

• With experience, you can make your own decisions; a puddle that is on a hard surface, with no sharp edges and is not too big is unlikely to cause you any issues. Idle into it very slowly and if you are comfortable, proceed with caution.
• If you see someone drive through the crossing and are confident you will have no issues
• If there is the chance of salt water crocodiles in the water (like many of the northern parts of Australia!)

If you are at all suspicious of a water crossing, its better to be safe than sorry. Get out of your car and have a good look, poke the crossing with a stick or walk it; you will never regret getting wet if it prevents serious damage to your 4WD!

Remember the water flow

For river crossings, one of the most dangerous aspects is the speed at which the water is flowing. Sometimes its obvious; if water is raging downstream at a reasonable height you would be mad trying to drive across it. Water is intensely strong, and has pushed plenty of 4WD’s off the crossings and into the river. Not only is it extremely dangerous for your 4WD, but you can easily put your lives and passengers at risk.

Again, this comes down to experience; if it is over wheel height and flowing quickly, you are taking a big risk. If you can’t walk the crossing easily, you shouldn’t drive it.

Another tip is to put something on the water and see how quickly it floats downstream, but bear in mind the under current can be stronger than the surface.

Again, if you aren’t sure, is it really worth the risk?

Know your maximum depth

4WD’s are not boats. They are designed to cross some water, but there comes a point where it is simply too deep for your 4WD to safely traverse. Your owners manual should tell you how deep the vehicle can wade (remember this is still water, and doesn’t factor in water flow!).

Most 4WD’s range from 200 – 800mm without snorkels. If you exceed this, you risk serious engine damage.

It’s worth looking under your bonnet and seeing where the air comes from; my old Hilux had its air intake right at the front of the bonnet; one decent gulp of water through the engine bay and it would have been all over. The higher the air intake, and the less likely it is to get water into it the better!

This is one aspect where you absolutely must not risk it. If you suck water in through your air filter, you can completely destroy your engine in seconds.

Even with a snorkel, you’d be mad trying to drive through something deeper than just above the bottom of your windscreen. At that depth, you risk having your vehicle float, and lose the required vision to safely control your crossing.

Know your 4WD

The more you know about your 4WD, the better off you are. Not only do you want to know the maximum wading depth, but you want to know about any electrics that could cause issues, whether you have diff breathers, where your low points are under the vehicle and how much of an angle you can tilt on before it becomes dangerous.

If your radiator fan is direct drive (that is, it spins all the time), you risk damaging your radiator badly by allowing water to make it harder to turn the fan.

The more comfortable and knowledgeable you are with your 4WD, the better off you are!

Install a snorkel

A 4WD snorkel connects to your air box, and pulls air from near the roof height of your 4WD, which in theory means you can drive through deeper water. However, it doesn’t guarantee the safety of your vehicle by doing so! Water above bonnet height has a whole series of other risks that you must consider. In general though, No snorkel; stay out of the water with your 4WD.

Check for air leaks

With so many different types (and qualities) of snorkels on the market these days, its important to make sure they are sealed completely. Usually the snorkel will not leak at all, but there is always a few joins in between the air box and the snorkel itself, as well as the airbox down to the engine.

Make sure there is no air leaking, or you may still drown your 4WD even with a snorkel fitted! Hose clamps, cracked elbows, poor sealant and vibration damage can result in air being pulled in lower than your snorkel entry, which also means you can suck water in and do serious damage.

Ensure your tyre pressures are correct

Tyre pressures are critical when it comes to 4WDing. There is a direct correlation between tyre pressures and traction; running the wrong pressures when you are attempting a water crossing can easily result in a drowned 4WD. Picking the right tyre pressures depends on your vehicle, what you are carrying and the terrain you are driving on. Have a look at 6 reasons 4WD tyre pressures are critical for more information.

Get your tyre pressures right though, its not worth the risk!

Engage maximum traction

You want maximum traction when it comes to water crossings. Not only do you have to push water out of the way, but you may have to battle soft surfaces, holes, rocks and water current pushing you the wrong way. As a minimum, you should have the front hubs locked, your 4WD in Low Range and the center differential locked (if you have one).

If you have front or rear Lockers, they are also a great idea, depending on the application. The more traction you have, the less likely you are to stop moving, and drown your 4WD!

Remember your electrics

Electrics and water don’t mix very well. On petrol engines especially, water can cause huge dramas with electrics. The way to avoid this is to reduce the water that contacts them; the correct speed and a water bra is a good start, along with silicon spray or WD40. This repels water from the electrics, and keeps them dry!

You’ve probably all seen a petrol 4WD go through some water, and run rough for some time after. My Hilux used to splutter badly after some crossings, and we had to open the distributor once as water had gotten inside on a crossing, causing it to stall.

Check the exit

It’s easy to inspect the crossing at the start and middle, but a lot of people forget to check the exit as well. You are in a pretty sticky situation if you get to the end of a long, deep water crossing and come to a vertical exit! Always make sure you are able to safely exit the crossing too!

Use the right momentum

I wrote a post a few weeks ago covering 4WD momentum. Water crossings need to be approached with the right level of momentum, or you will do damage. Too quick and you risk pushing a heap of water into your engine bay, and too slow and you risk getting stuck. What you are looking for is to create a bow wave, that leads your 4WD through the crossing.

Make sure you pick the right gear, and stick with it. In most cases, second gear in low range works perfectly. Keep the vehicle in its optimum rev range and drive the crossing with the best chance of success. Do not use the clutch in a water crossing; you can get water inside, and it will never be the same.

Go in prepared

If you aren’t 100% confident with a water crossing, take the time to hook a strap onto the front or rear Rated Recovery points, and then hang it (or wrap it) out of the way, where it is accessible should the worst happen.

Have another vehicle ready, so if you do get stuck, it takes a minute to hook the strap up and pull you out, rather than 10 minutes trying to hook a strap on in freezing cold, muddy water!

Use a water bra

A water bra (or just a tarp), can be attached to the front of your 4WD just before going through a water crossing, and dramatically reduces the water that flows into your engine bay. These are cheap insurance, and work extremely well, especially on petrol 4WD’s.

Remember the risk

Above all, consider the risk. If you aren’t confident, is it really worth it? What could possibly go wrong, and what would it cost you? Does your 4WD insurance cover you for water crossings, and for the area you are in?

I’ve seen far too many 4WD’s get written off, or badly damaged through water crossings that haven’t gone to plan. They can be a lot of fun, but they can also literally dampen your trip away.

Have you had any close calls, or bad experiences with water crossings? What have I missed in this post? Leave a comment below; I’d love to hear from you!

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