Resistance when blowing into diff breather??

[EsbenDenmark]

I am having a leak in my front differential and I am wondering if it due to too much resistance in the diff breather. I have installeret a original diff breather but I was surprised to feel quite a bit of resistance before I felt the little diff breather "open up" (blowing air into the tube like if pressure is building up in the diff)

Should there be any resistance? Or should there be free air flow?

 

[Felde]

Should be rather free flow.
I suppose you refer to the OEM breather with the cylindrical cap? I found those quite difficult to clean with the cap on. Even soaking & flushing with brake cleaner didn't work great. I eventually removed the cap to get the grime out.
Cheers Ralf

 

[JuanJ]

Hello,

The breather is a valve and its cap is supposed to open when under pressure.

It is better to raise the breather by using a longer hose.

There is a fitting that bolts into the front axle. The breathing hose connects into this fitting. If the fitting is not making a tight seal, oil leaks from it, especially if the differential is overfilled.

Check the axle fitting for proper sealing with both the axle and the breather hose.





Juan

 

[EsbenDenmark]

Should be rather free flow.
I suppose you refer to the OEM breather with the cylindrical cap? I found those quite difficult to clean with the cap on. Even soaking & flushing with brake cleaner didn't work great. I eventually removed the cap to get the grime out.
Cheers Ralf

Yes I have a OEM breather and it is almost new and relocated to enginebay.
Is totally clean and never been even dusty

 

[Felde]

Yes I have a OEM breather and it is almost new and relocated to enginebay.
Is totally clean and never been even dusty

Well, as Juan said: It's essentially a valve, so some pressure is needed to open it.
Breathers seldom clogg from external dirt or dust, but rather from grime from inside the axle:
Is your axle diffoil clear?
Have your axle knuckle seals been bad and your breathers clogged at some point?
Do you have free spooling hub locks?
Bad seals not only let oil seaping out when the axle warms up and builds up pressure, but also suck grease in when cooling down again.
The MOS2 grease makes the oil look greyish dark.
Unlike the back axle, which is constantly moving, sucked-in grease in the front axle, which is probably not moving that much, does not mix with the oil but may form flocks floating on top. That might clogg an even recently rebuild breather quite quickly again.
I recommend to thoroughly clean out the hose and breather again and carefully observe what kind of grime comes out.
On the next diff oil change: Lock your hubs before, so the diff gets spun passively, drive the axle warm before oil change, to allow best possible emulsion of any grease to flush it out.
Good Luck Ralf.

 

[Squash]

Pull the hose off at the axle tube. Then you determine if the hose and cap are free and clear if not, clean or replace as required. Next, inspect the tube to axle. This should also be clear. If gunked up poke a piece of wire into the tube and clean it up.
If the above items are in good shape then suspect a leaking axle seal.
An axle needs to breath depending on heat or the cooling of water for instance.
If the breather is plugged then something is either expelled or sucked depending on temperature.

 

[LDRF]

Lots of feedback here.

I recently did the rear breather on mine. It was plugged completely. I gave it a two day soaking in Evapo-Rust. Over the two days, I fiddled with it and it started to loosen up. I eventually got it unclogged.

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It is a check valve; there should be little or no resistance blowing out and you should not be able to suck air in.