Extending Diff Breathers

[oldblue]

I need to add my 2c worth:
You must remove that springy cap and have the tube open , if you don't then you have "not" really changed a thing.Just made the tube longer.
One thing that needs to be looked at.
" how good are the seals?"
Any improvement in the breathers still wont stop the seals from leaking.if they are old and warn out.

[rangimotors]

i see an air bed pump, good thinking bat man, only thing i'd be careful of and wanting to test is how long they will run for some dont like to run for very long without burning out or trying to go on fire, good idea though just run it for a few hours before sticking it somewhere important or even better put it on a switch/ relay so you can flick it on and off.

[wjw]

switch/ relay so you can flick it on and off.

Just hook it up to your electric fan switch, when you turn it off for the water crossing, air bed pump comes on... although you have to have an electric fan for that to work

[rangimotors]

any idea how much pressure ya can get away with putting into diffs without creating issues think ill just use a 12v pump but put a restrictor in the line

[Azza]

switch/ relay so you can flick it on and off.

Just hook it up to your electric fan switch, when you turn it off for the water crossing, air bed pump comes on... although you have to have an electric fan for that to work

Or get really technical and rig up a moisture sensor as the main switch to control the pump automaticly.

[Steve_t647]

I know of one jeep running 2psi into the diff's I think the air pressure only needs to be enough to offset the suction pressure for the water, and I think he said he looses oil through the seals with 2psi.

Also there is so little water that gets in (with good seals) I have found the open breather in the top of the snorkle hat to be fine (for me so far), the amount of air sucked in and pushed out is less than the volume of the length of pipe and the suction required to suck water past the seals is a lot more than the air through the open tube.

Yes protect your diff's and diff oils but you still need to check them regularly anyway.

[oldblue]

You can work this out, 14.7 Lbs per square inch,at 33 foof depth.
So for each 300mm of water depth, there is only 1/2 Lbs per square inch of water pressure trying to get into your diff.
At 1.2mt deep you need 2 Psi
correct me if I'm wrong.

[H2OLOVA]

I run a high volume (but low pressure ) air bed pump. Its a 12v unit and like Bill said i have it on a switch so when the electric fan goes off the pump comes on and vice versa. I run it into a home made manifold and run pressure into both diffs and my gearbox/transfer case. Have done some pretty deep crossing and (touch wood) haven't had a drop of water in anything. I don't loose oil either, but i did replace all the seals in the axles and input shafts at the same time.

[timotheus]

I was just in RIPCO and saw 2 options, a air-bed pump for $14.95 and a cheap tyre pump that claimed 250psi!! for $19.95. Both were 12v.

[rangimotors]

the air bed would be the way to go or you'll end up pupming way to much pressure in there and probably push all your oil out the seals, as was stated low pressure high flow is ideal

[Steve_t647]

H2OLOVA

Have done some pretty deep crossing and (touch wood) haven't had a drop of water in anything. I don't loose oil either.

not sure about you I am confident you ended up with water in your intake from that little puddle you were rolling in in your profile pic I am sure I remember you had water in it playing around in the ashley up round your ankles in the car tho.

High volume low pressure sounds like the go tho, have any of you checked the temperature your diff's get to? Mine are always pretty warm to very warm (wear good gloves) on long trips with good oil's and seals no loss they don't wine or have huge backlash and this is on two different Hiluxes. If in 4wd they both (all 4 actualy) seem to be the same temp.

Sorry for the Hijack it is related tho sort of

[rangimotors]

yea i think thats why they try and suck the water in when they are super hot and rapidly cooled eg submersed in water i think that most are correct in the fact that a good diff breather extension setup is fine and really all you need, but for 15 dollars and a little time its probably no harm (and kinda cool) to pressurise them

[rokhound]

I run a high volume (but low pressure ) air bed pump. Its a 12v unit and like Bill said i have it on a switch so when the electric fan goes off the pump comes on and vice versa. I run it into a home made manifold and run pressure into both diffs and my gearbox/transfer case. Have done some pretty deep crossing and (touch wood) haven't had a drop of water in anything. I don't loose oil either, but i did replace all the seals in the axles and input shafts at the same time.

Shit yeah Jas, what a good idea . Airbed pumps are the go because of the high volume, but low pressure. When you use a central manifold system you can run all lines from both diffs, gearbox, transfer, and dizzy (for petrol rigs) to it. You then hook the outlet from the airbed pump up to this manifold as well. Make sure you have a decent sized inlet hose for the pump though or you will choke the volume that the pump produces.

[wjw]

The airbed pumps have 1" inlet and outlet on them.

[kiwipete]

sorry i should of said, most have a 230 input but then its steped down to 12v dc so if you cut out or just dont use the 230 input and connect directly to the 12v input your sweet

If you can supply me of a brand name for a pump like you suggest, i'd appreciate it as the ones I have here are 130V only. (Stellar brand)

[rangimotors]

no problem will do, as im off work at the mo it mite be a little while but ill try get in asap, to be honest i never thought about the airbed pump and i think it probably a better option.. but no worries if you still want details

[kiwipete]

Think I will stick with the Aquarium one as I know they will chug away continusly for years basically without a hitch.
Will put it through a relay off the ignition so i never have to worry about turning it on so to speak.

[rowinz]

i removed the breather cap can i just zip tie a tube over the sticky out bit and run it to points higher?

I did just this on my old 40 series. I used 10mm clear tube from Mitre10 and 13mm irrigation connections. Manifolded the diffs and tfr/gear box together into a loop in the engine bay. The 10mm tube can take the 13mm connectors if you put them in boiling water to make the plastic a bit more pliable and use some persuasion. No need for clamps to hold them in place as they are nice and snug. I used small hose clamps to attach to the protruding breather connectors on each part.

You can work this out, 14.7 Lbs per square inch,at 33 foof depth.
So for each 300mm of water depth, there is only 1/2 Lbs per square inch of water pressure trying to get into your diff.
At 1.2mt deep you need 2 Psi
correct me if I'm wrong.

good old physics...static pressure
= density x gravity x depth
= 1000kg/m3 (water) x 9.81 m/s2 x 1m (depth) = 9810 Pa

= 9.81kPa ( then divide by 6.9kPa / psi)
= 1.42psi at 1m water depth

this doesn't take into account any suction that may be caused by rapid cooling of diffs, nor extra pressure caused by water flowing around wheels, etc. I'd suggest 1.2 - 1.5 times the pressure expected for the depth you want to drive through. That way any local pressure fluctuations around the seals should be accounted for.

[rangimotors]

Think I will stick with the Aquarium one as I know they will chug away continusly for years basically without a hitch.
Will put it through a relay off the ignition so i never have to worry about turning it on so to speak.

yea i agree if your have it going into a maniflod with lines coming off it and you only turn it on as you hit the water it means you need to pressurize the maniflod and lines before it even starts on the diffs. so yea i like the idea of having one going all the time and not having to stop for a min or two before its presurized and ready for action

[H2OLOVA]

H2OLOVA

Have done some pretty deep crossing and (touch wood) haven't had a drop of water in anything. I don't loose oil either.

not sure about you I am confident you ended up with water in your intake from that little puddle you were rolling in in your profile pic I am sure I remember you had water in it playing around in the ashley up round your ankles in the car tho.

Ahhh yes but that wasn't a drop that was a whole river

[fweddy]

I'm revisiting this old thread cause I have water in both my diffs with extended breathers and new seals and all - Think its time to pressurize them now.

Considering the above info on the topics - does any one have any further info on the topic, and what has worked for you?