Breathers for Diffs?

[Jaco Versfeld]

Hi there,

Is there a standard connector that I can fit to the diffs, in order to connect pipes to be routed to the engine bay?

What type of pipe should I use for the breathers?

Do I need to fix the gearbox's breather as well, or is the breather in the gear lever?

Thanks,
Jaco

[CasKru]

You can basically use any pipe that won't perish with age and heat and that can handle the pressure (not pinch closed).

As far as I know you are correct regarding the gearbox breather.

[ThysdJ]

Hi there,

Is there a standard connector that I can fit to the diffs, in order to connect pipes to be routed to the engine bay?

What type of pipe should I use for the breathers?

Do I need to fix the gearbox's breather as well, or is the breather in the gear lever?

Thanks,
Jaco

Yes you can buy standard brass fittings that screw into your diffs in place of the stock "breathers". You can take on of yours out to compare the thread and buy the correct ones. In my case we used the green pipe in the picture below as breather pipe, but any other plastic pipe would do.


I am not sure about the gearbox.

[ThysdJ]

Jaco check this thread out

viewtopic.php?f=3&t=2378

[Scorpion]

Or if you are lazy (like me! ), you can buy a complete kit for the Hilux from Rebel4x4.co.za - cheap cheap!

[Dadz Toy BFI]

Most Seasoned Overlander Lux's I've come across have your common garden hose fitment as per kaspaas' photo, no fancy one way valves, just at a reasonable height.

[Family_Dog]

Bulldog's front diff breather extends up into the engine bay and is terminated by a normal petrol filter to keep muck out. The rear breather was also quite high up, exiting at near the petrol filler cap. Must check this out, can't remember seeing it there lately since the respray.


-F_D

[Arch]

G'day,
I'm new here and this is my first post.
Jaco, I run extended breather hoses on both diffs, the gearbox and transfer case.
The fittings are brass which I picked up from an auto parts retailer - i just removed the breather in the carpark and matched the thread to what they had in stock. From the fittings I run enough rubber fuel line to take the ends up high, e.g. under the bonnet on the wheel arch and on the wheel arch inside the well body at the rear. Finally I've got a disposable fuel filter on the end of each one to keep the muck out, but still allow it to breathe.
All up it cost me around Aussie $30.00 or about 200 Rand.
One thing I'd suggest regardless of which method you use, check the hoses every 6-12 months to make sure they're not blocked. If they block up, the pressure can blow your outer seals.
Cheers,
Arch.

[Stephen]

Salute',

If my memory serves me right the fitting is a 1/8 BSPT (British Standard Pipe Taper) or BSP (British Standard pipe wich has a straight thread) with gas pipe fitting other side (currugated push over and screw with hose clamp). Does not matter.

Use Teflon tape to seal. Do not be Tarka and over tighten, as the Brass thread portion will break off. Beware pse!!. Will find among the gas fittings counter (Brights in the Cape) I used a fuel pipe (bit pricey) as it is hydrocarbon resistant and will not close. Tied the front diff end to the brakes master cylinder reservoir with Tie-Raps and the rear into the loading bin via the 2nd battery cable entry. Use a small fuel filter as suggested by others (I used another type viz Nylon bug screen/silencer from Hyflo Cape).

Have seen some people re-use the existing breather and re-mount on top.

[Duwayne]

hi guys,
I am getting the parts soon teh diff breathers for my bakkie. I am going to install to make sure it fits (import diff). if all works well would anyone be interested to get the kits from me? i can order extras then. let me know thanks D

[CasKru]

Duwayne. IF you have difficulty fitting yours, I also sell diff breather kits..

Boerie-Diff-Breather.png (376.24 KiB) Viewed 5536 times

[Duwayne]

THANKS CASKRU, Didn't know that. How much do you sell the front and back for?

[CasKru]

THANKS CASKRU, Didn't know that. How much do you sell the front and back for?

Price is the same for front and back @ R160 each.

[Stephen]

Hi Gents,

I saw a brass sintered filter as vent / bug screen in the photo. Not being negative, watch out if they turn green then they are basically blocked and then the water will be drawn into the diff. They turn green due to corrosion (salty river water ie brak water, sea fog, etc).

I have seen green blocked ones when they are used on pneumatic solenoid valve vents with 140 KPag behind them.

Go well.

Stephen

[mushroom]

Hi,

We are going to Moremi in Sept, and with the river crossings etc.. thought it might be a good idea to fit some breathers.....but then I got thinking...

What is the volume of air in the diff, above the oil level? Oil wont shrink when cooled down, especially seeing as though the diff temp cant be that high ? (I havent a clue but cant imagine it would be higher than say 80deg C). So when you go through water and cool the diff down (so 80 - 20) and the air "contracts", how much negative pressure is actually created???? Reading off a psycrometric chart (at 1700m altitude) - air cooled from 45 deg to 20 deg only loses 7% of its volume??

Then you whack on what looks like a really thin pipe (1/8" ??) and run it for a couple of meters into the loadbin or firewall. This small diam pipe must have quite a bit of frictional resistance. Then add the pressure drop over the fuel filter, and I'm wondering if it really sucks air in all that way, against the filter pressure drop and the frictional resistance of the pipe ???.

I'm no scientists but I do know that air will ALWAYS take the path of least resistance, and in this case how much air is it actually??

So, I will be purchasing some of the diff breather pipe, and will try and blow a candle out through 2m of this pipe, with fuel filter, and see if it happens easily or not...... maybe its best to run a really short piece just under the loadbin and bend it downwards (creating an inverted u-trap)

[Mud Dog]

James, the fact that the manufacturers see it necessary to fit diff breathers should tell you something already. The vacuum created is enough to engage vacuum lockers if the breathers are blocked, so it's substantial enough and if your axle is submerged (doesn't require much depth) it's going to pull water in past the seals ... either at the wheels or the pinion. Those bearings will take the first knock.

Personally I wouldn't take the chance, and at less than R150 for a DIY installation, it's less than ¼ of the cost of replacing the diff oil with a premium quality product, not to speak of resultant damage inside the axle over time if it's left.

[mushroom]

Good point about the manufacture spec....hadnt thought of that. Will be doing them breathers

[Mud Dog]

Worth it! At the time I did mine on the 'new' bakkie (last year some time), I think it cost me a princely sum of R136 for everything on both diffs.

[Mr_B]

Just some info for the Vigo guys, the front diff and gearbox appear to have decent OEM breathers, they exit high up in the engine bay close of the alternator and battery, if you want it higher you can just extend them from there. The rear breather is the classic one found on the SFA and IFS as well, so that one needs replacing/modding! I reused the original tapered fitting and modified it, simply cause I couldn't find the right fitting at Goeiehoop and HyFlo... think I just looked miss! Glad I did the mods, cause I managed to get bogged down in a muddy water hole to day!

[Mud Dog]

Just some info for the Vigo guys, the front diff and gearbox appear to have decent OEM breathers, they exit high up in the engine bay close of the alternator and battery, if you want it higher you can just extend them from there. The rear breather is the classic one found on the SFA and IFS as well, so that one needs replacing/modding! I reused the original tapered fitting and modified it, simply cause I couldn't find the right fitting at Goeiehoop and HyFlo... think I just looked miss! Glad I did the mods, cause I managed to get bogged down in a muddy water hole to day!

I think this is probably the very worst case scenario .... or like Cassie's motor failing him today. You end up not just passing through, but sitting for a while and giving the diffs even more time to cool down during which your axles remain submerged. It simply has to suck air through a h/l breather or muddy water through the seals or low level breather. Remember that the seals are designed for optimum prevention of ol leaking out, but this means that they're not so wonderful in preventing something like water leaking in.

The boating guys that launch off their trailers by submerging them will tell you how often they have to change seals and wheel bearings .... where possible some of the guys used to fit the seals the wrong way around to minimise water ingress. I used to have to replace mine every two years or so.