OB Approved Water Crossing: Snorkels and Preparation

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Jeff Graham

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Let's talk about Snorkels. Water crossings, is what many people think of, when they see a snorkel on an overland vehicle. In reality, we know that it's most common use, is to pull in cooler cleaner air. But if a vehicle is properly prepared, can also be used for water crossing. Generally: as long as a vehicles has a good air source, spark (Petrol/Gas engine), and fuel they will continue to run

Most modern SUV's and trucks mechanical systems are surprisingly water resistant. Older vehicles Achilles heel has always been the electrical distributor. Modern vehicles, and diesels, do not have distributors. They are less prone to water infiltration. Many of the electronic components of SUV's and trucks can have their resistance to water enhanced, with the use of dielectric grease on the connectors.

The engine is not the only part of the vehicle that needs a source of air. When the axles, transmission, and transfer case: hits the water, they cool down rapidly. As they cool, the Atoms that make up the steel, vibrate slower. The kinetic energy decreases, and the steel shrinks. The same thing happens to the lubricant in these components. This shrinking creates a vacuum. each of these components have a breather tube, that allowes this pressure to be regulated. As the steel shrinks, air is pulled in to regulate the change of pressures. But during a water crossing, this tube can be submerged. It pulls water in, not air. When the water enters, bad things start to happen.
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To prevent this catastrophe, we must extend the breather tubes. They must be moved to a higher and/or safer location. Here is an example of a safer place to move the tubes.

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My breather tubes have been relocated to my engine air box. The air box is fed through my snorkel. All the potential ingress points for water have been sealed. It is common to use inexpensive Fuel line, as the extended breather hose.

This is an example of inexpensive role of Fuel Line:


These preparations should be sufficient to allow most modern SUV's and trucks to perform a safe water crossing. I hope this short overview is useful information.
 
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brien

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Great info, thank you. I think i'm going to try and go this same route of using fuel line. I looked at buying a breather extension kit but $80+ is a bit steep for what they are.
 
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Jeff Graham

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I think I was a total of $30 in to this project. All the bits can be sourced from the local parts store, so a good Saturday afternoon project. The hardest bit was finding the Transmission and Transfer Case breather tube. Took a lot of searching on the Jeep. But once found, easy to extend.
 

Jelorian

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Just curious as to how you are making the extension. Are you connecting to the ends of the existing breather tube or are you just replacing the existing tube with a longer one? If you are connecting to the end of the existing breather tube, what hardware are you using? Thanks!
 

Jeff Graham

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Just curious as to how you are making the extension. Are you connecting to the ends of the existing breather tube or are you just replacing the existing tube with a longer one? If you are connecting to the end of the existing breather tube, what hardware are you using? Thanks!
I chose to replace the axle OEM, with a new longer tube. I extended the Transmission and Transfer case breather, because it as not easily accessed.
 
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Mike W

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On an LR4, the front/trans/transfer breathers are extended to the top front of the engine bay from the factory and have a membrane material on the breather that prevents water ingress if you go over the hood.

I think the larger problems occur when the water would hit the hood cowl aggressively enough to come into the cabin air filter area. This can be an issue because under/near the cabin air filter is one of the main ECU (Its tucked up under the dash on the passenger side, up off the floor). I just recently learned that the rear diff breather is actually run up near the fuel tank evap system somewhere in the body (i think).

Point is... on newer vehicles, know where your computers are also. Many vehicles have computers under the front seats. I think LR3/4 have nav/stereo components under the passenger seat. Luckily the land rovers have much better door seals than on previous models, but it's still a risk. An outer seal (that is against my sliders) and the full door inner seal which is pretty beefy.

I don't plan on fording anything I don't have to. It just adds risk of longer term issues and getting mud and crud up in things you can never easily access again.
 

Jeff Graham

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On an LR4, the front/trans/transfer breathers are extended to the top front of the engine bay from the factory and have a membrane material on the breather that prevents water ingress if you go over the hood.

I think the larger problems occur when the water would hit the hood cowl aggressively enough to come into the cabin air filter area. This can be an issue because under/near the cabin air filter is one of the main ECU (Its tucked up under the dash on the passenger side, up off the floor). I just recently learned that the rear diff breather is actually run up near the fuel tank evap system somewhere in the body (i think).

Point is... on newer vehicles, know where your computers are also. Many vehicles have computers under the front seats. I think LR3/4 have nav/stereo components under the passenger seat. Luckily the land rovers have much better door seals than on previous models, but it's still a risk. An outer seal (that is against my sliders) and the full door inner seal which is pretty beefy.

I don't plan on fording anything I don't have to. It just adds risk of longer term issues and getting mud and crud up in things you can never easily access again.
This is a very good point, thanks! Some vehicles, Jeep JK as an example, ECU's are built to IP67 standard. It's only the wiring plugs, that present a risk.
 

iluvdrt

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If I am planning on fording water I also put a balloon or glove over my dip stick fill tubes and rubber band them on tight. I have had water intrusion through these areas before.

Additionally any seals that are leaking will also let water in, so ensure your vehicle oil seals are in good shape as well.
 

DCFISK

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Just curious as to how you are making the extension. Are you connecting to the ends of the existing breather tube or are you just replacing the existing tube with a longer one? If you are connecting to the end of the existing breather tube, what hardware are you using? Thanks!
I am considering an ARB diff breather kit. Anyone have experience/opinions on them?
 

Jeff Graham

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I am considering an ARB diff breather kit. Anyone have experience/opinions on them?
I have heard only good things about the ARB kit. I wanted to run everything to the Airbox, or I would have considered the ARB kit.
 

4wheelspulling

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Breathers are on my list of mods that I want to do soon. You know the kid that was always wading through mud puddles? That was always me! Jeff, thanks for the write up! Benz.
 

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thanks for the info. Just did my snorkel install the other week and knew that i was going to have to do the diff breathers and t case but i just didn't have a good idea of where to put them. Also does anyone have an other info for electrical components that would need some attention so water wont destroy them?
 

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