Wednesday, July 4, 2012

Water Crossings - Tipps and Tricks

You might have noticed that I have posted a significant amount of pictures with more water than truck in them. O.k., I have not gone really deep, really not that deep. But still, for those of you who are getting prepared to do a similar tour or just want to prepare your vehicle for crossing rivers that are a little deeper than your hiking boots. Here a couple of modifications I have done to my truck and things you might want to pay attention to before you go...

...diving with your vehicle.

My truck has a visco fan clutch built into the radiator fan. This makes it comfortable since the visco clutch of the fan will slip should the resistance of the water be too high. Which means I do not need to worry about the fan before diving. Should your car be equipped with a solid connected engine driven fan, often the case with older vehicles, and you decide to go through as deep of a river that might float your engine bay. You might want to untighten/remove the fan belt prior to going diving. The water could damage your fan blades otherwise. If your car or truck is equipped with an electrically driven fan I would recommend to install a manual switch with which you can override the thermostatically driven on/off switch of your fan. This way you can make sure your fan will not switch on all of a sudden while floated and might get damaged. Alternatively you might just disconnect it manually prior to going in to the river, by simply pulling its connector apart. 

Most river crossings are not a big issue. Unless you drive a Ferrari or a Porsche, with a river crossing like that you will not be required to do anything to you car, Crossings like that are not a problem, even for a 2WD passenger car. 

Sometimes you need too think about floating objects on the river that might damage your car... well as the current of certain rivers. 

Other times you're river crossing is as easy as can be.

Even if the track itself might not necessarily require to engage 4 wheel drive, I usually lock the hubs at the front axle and put it on 4WD, should I run into any unexpected issue I might be glad to be able to count on the extra traction. 

Do not underestimate the current. First it might be as strong as it might carry your car away, especially risky at beach driving - Tide. Sometimes not even a tight Bikini helps. But more often you need to think about what even smaller rivers with a significant current might carry down the streams, rocks or log pieces can damage your car or stop you in the middle of the river.

I have modified the axle vents, this is in the front where I pulled it under the hood, not as high as the snorkel sits. But until the engine bay is solidly floated up to valve cover level you can do pretty good diving anyways. Additionally the vents are originally equipped with a little but very simple valve, that gives basic protection of a water entry.

The rear axle vent I have pulled up in the area between body and door up to the upper hinge. This area is generally well protected from water unless you go and do serious surfing. 

I have not done any specific mods to the exhaust in regards to water crossing, but even when unter water this will work fine as long as you keep enough trust on the accelerator. Meaning you want to chose the right gear before going in, you can switch gears while your exhaust is farting under water, but you want to be really fast, otherwise the water will  shut your engine down. 

Air vents on the inside of the car prior to removal
My truck is factory equipped with a cabin vent system that allows for the doors to be closed properly while all windows are closed and they function as an air-out vent with a flapper valve in it while you have the defog blower running on max and all windows cosed. I have removed those vents as they might be a potential water entry.

And manufactured some aluminum panels to blank it off.

I insulated the area from the inside and... 

...closed it off by glueing my panels in there. 

Most of the time it is not really serious.

Sometimes just a lot of dirt flying around.

When you drive through Cafe Latte it's a little different, you might never know what the underground is like and it is challenging to guess the depth of it as well. And crocodiles and alike...

If you go real slow you might not float as much of your car as if you go faster, but you might need some momentum to overcome the water's resistance and if the underground gets very muddy you might wanna have some speed to get through and up and out on the other side.

Watch for large rocks. 

Most are easy. Most are...

When you go as deep as that it would have been smart to go and explore on foot before getting in. Also make sure your ventilation flaps are closed. And for as deep as that you will require to modify your car with a snorkel

Sometimes the rocks or the traction is the bigger issue than the water.

If you go deeper than your fuel cap's level is you  might want to drain the water at your diesel or fuel tank and/or at your diesel filter within the next couple of days after a series of the water crossing. 

Always dry your brakes after coming out of the water, the performance when they are all wet is very poor, heating them up will be the best way to dry them and protect them from rust. More so for discs than drums. If you have to park your car imediately after a river crossing, put it in gear or use chocks rather than pulling the brake as it might not be possible to release it due to fast rust build up between brake shoes and drum. 

Don't count on others having made it, they might have simply backed up to the river from the other side.

Evaluation before going in is actually key. If I was just not that lazy to get my feet wet, and not as much afraid of crocodiles... The exit here is several hundered meters upstream. This was one of the most challenging crossings so far.

I got water into the headlights, through their respective vents, which while driving more off-road kind of tracks, had hit the bulbs while I was driving with lights on, and damaged one of them at once. Here I was sun-drying the headlights, prior to reinstalling them with new bulbs.

Looks like a big deal but the replacement is fairly easy and the system is designed so cleverly that you can remove/reinstall the headlights without touching their level-adjustment. 

The broken H4 lamp. It would not withstand the cold water splash while it was burning hot.

Sometimes I crossed bridges where I wished it was rather a river to cross.

Sometimes they look harmless, but... this one was much deeper than it appeared to be from this side and a couple of large unvisible rocks made it more exciting than I would have expected.

Water slowly rising over the chassis-level.


...and out again.

Interesting drivers side window view.
Don't underestimate that current, even if your truck weighs three tons.

Give me a river to cross, please! Some times I just don't trust those bridges. 

Very common during rainy season in tropical countries.
And compared to mud, luxury.

After beach driving or salt water crossings a good wash with fresh water soon thereafter will be appreciated by your vehicle.

Enjoy it, this are fun driving conditions you will hardly ever find back home. At least not were I live.

Of course you can cross the waters like that as well. And you won't need the most important piece of equipment for river crossings...

...a snorkel.

Water crossings down to Key West in Florida won't require a snorkel.

My truck is full of equipment and kind of heavy. If your's is not or you just head out for the day or a weekend and you go really deep you need to think about that your car might start floating and you might lose traction. Check this Ozzy guys out to see how that works. And keep going.


  1. Wow, thats all very interessting stuff and amazing pictures. Thanks to tell us all that ! Have a good further trip ! Luki from GL-South

  2. Heya Thomas, great write up. May I add that choosing the right gear is essential. Changing gears is something you don't want. Other than the possibility that the engine will die, the possibility of stuff [sand, grit, little stones and general debris] entering between the clutch plates is something you might want to avoid.

    Just my 2 cents.

    Adventurous greetings,