Diff Breathers

[crump]

If I extend the rear breather hose and instead of running it up to the engine bay I run it into the cargo area thru the wheel arch, (because its easier) would the inside of the Fender start to smell like a fish and chip shop?

[disconut]

I have run mine up to the to of the wheel arch then back down to the chassis rail. This 180 degree bend acts as a vacuum breaker preventing a cooling diff from sucking water in.

Trev.

[crump]

call me a moron, (or weird apparently) but it already has that bend standard, so whats the diff?(pun intended)

[disconut]

Mine was missing from new. However if you have it, why do you want to put it into the car?

Trev.

[crump]

Dunno, thought you had to get them up high for water crossings, if there ok in the wheel arch with the 180 bend, why do all these mags and forums talk about DIY jobs , 'put ya breathers up into the engine bay, mate'
Not that I look at any of those other forums, "cos I pity the fool that visits other forums", sorry had to do it! https://www.aulro.com/afvb/ https://www.aulro.com/afvb/

[disconut]

My guess is they dont understand the point of the loop, or they dont have loops and suck in water. I saw a note in a book that suggested tying them all up to the snorkel. 8O Jeez they must be trying to drive under water.
My understanding is the car will eventually float, and you lose traction anyway, so why bother? LR quote 600 mm as the wading depth. This must be on the safe side of floating away.

I also found all my breathers in the engine bay laying down! Useless, they need to be vertical with the 180 degree bend and a longer tail fitted to be effective. They are all tied up correctly now.

Trev.

[disconut]

Further to the above, you cannot force water into a sealed cavity. (try blowing into the breather tube). When a hot diff hits cold water, the hot expanded gasses cool and cause a negative pressure (vacuum), which can draw in the water. However if you have a loop, as the water attempts to go over the top of the loop a bubble forms and breaks the vacuum and the water (liquid) drains away.
Having all you breathers in the engine bay assumes that you will not put you bonnet under the water, ever!

Trev.

[DEFENDERZOOK]

<span style="color:blue">breathers are best fitted with some sort of filter....
the best and simplest being a cheap plastic fuel filter.....
if fitted to the bottom of the loop mentioned above it will provide a fair
amount of air for the diff to suck instead of water......


and used filters work better due to something the fuel does to them....
and they are cheaper again.......(free from workshops.....)</span>

[crump]

Well, what the hell did I buy? I have breather hoses mounted up in the wheel arch, they have a 180 bend in them, and they have a filter as well, but I bought it new?

[DEFENDERZOOK]

Originally posted by crump
Well, what the hell did I buy? I have breather hoses mounted up in the wheel arch, they have a 180 bend in them, and they have a filter as well, but I bought it new?




<span style="color:blue">looks like land rover took my advice.....</span>

[crump]

yours is the same year model, what set up did you get stock?

[DaveS3]

Run all breathers to the engine bay, witha fuel filter on top. Dont run them into the car, if the diff pressurises it sends oil up the breather then you car smells like EP90. That sucks.

[landrovermick]

Donet matter all that much so long as they are away fromt eh diff, when a hot axle housing goes into cold water it sucks water in through the oil seals anyhow.....

dont think that cos the diff breathers are up high you wont get water in the diff... cos you will, if ya take it swimming you have to change the diff oil soonest

mick

[disconut]

If you are going to take a river crossing, stop, have a brew, let the diffs cool down and then attempt the crossing.
The diffs in particular, contain a large mass of steel and as such will retain heat for a long period. The engine and gear boxes will also benefit from being allowed to cool off.
If you are not in a hurry, camping for the night and doing a morning crossing would be the best. However this is not always practical.
Breathers are there to prevent the seals from leaking or blowing out as the gas vapour needs to expand without pressurising the diff casing. The size of the tubing used is quite small, so a slow heat build up will allow the vapour to expand and escape, then air to be drawn back in again on cool down, all without seal damage.

Trev.

[cewilson]

I've always extended my breathers to the top of my firewall with a fuel filter connected. I figure better safe than sorry - and I know that they are above the water line.

As for the diff being hot and sucking in through the seals - this is not something that just happens on a day when you are crawling around in low range. To get a diff that hot that this would happen would take hundreds of km's, and even then you'd have to drive straight into it without a break.

Normal day-to-day four wheeling that most of us do - you will never experience this happening.

However - I do agree with the principle behind the loop - I just prefer the firewall personally!