ARB purge valve

Hi Tom,

Thanks for that feedback.

One of my concerns was the purge outlet getting blocked with dirt. I read on another forum about using a “T” connecter to connect the purge outlet to the diff breather line. He said that worked well.

Kevin

Hi Allan

Diff oil, generally caused by a poorly vented diff, or by a dodgy O ring inside the the diff itself. Its actually not that uncommon.


Regards

TrevorDavid

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Thanks TrevorDavid,
So ARB, instead of fixing their 'dodgy' product, are offering to sell you a further product to overcome the problem?
Hmmmmm!

Like TrevorDavid, the issue will happen if diff cannot breathe properly . I see someone said more if fast highway driving. That would definitely indicate a blocked breather causing axle housing pressurisation which forces oil out of the open solenoid valve. Unless diff rotation is somehow pumping the locker piston the problem cannot happen if diff is vented. Has anyone experiencing this problem ever unexpectantly had an axle or especially a pinion seal begin to leak????? Cause is blocked axle breather. Toyota breather ID are FAR too small. I drilled mine out so scum didn't restrict the very small hole.

@RMD .Your theory makes sense. I can confirm that small amount of oil blows up the line into my catch can after clearing oil from the line and the breather is not blocked. The system also holds air and locker works. Even clearing oil from line and not switching on compressor within 5000km there will be 20/30mls of oil in my catch can. Arb can't work it out either.

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Hi RMD and Maurice,
I agree with the essence of RMD's expression. A fundamental is that fluids move only when subjected to a force, e.g. gravity or a difference in pressure. And maybe a tiny bit from such as capillary action.
As the vehicle differential is usually below the height of the solenoid valve then gravity is unlikely to transport oil. This leaves pressure as the likely culprit. And obviously there needs to be oil in the path of the pressure difference for any of it to become present in the air line.
So the conclusion is that the locker piston o-ring seals must be leaking and there must be some diff pressure.
Declarations of the diff breather being "not blocked" may be in question unless it has been adequately tested. Visual observation may be inadequate. It is even possible that the diff vent may present as 'clear' when the vehicle is stationary yet become obstructed with solid oil when the diff is rotating. Such occlusion may provide the pressure necessary for oil (in liquid or vapour form) to be expelled from the locker airline connection, assuming that it has passed the seal rings.

I find Maurice's expression that "within 5000km there will be 20/30mls of oil in my catch can" a surprising amount amount of discharge. It seems more than I would expect from oil vapour alone and, as his catch can is positioned almost 1 metre above the diff, it would require more than a minuscule amount of pressure to lift liquid oil from the diff to the catch can without assistance from the exhausting diff locker.
My conclusion is that he does have leaky locker seals and he is also experiencing diff pressure in some way. Or that maybe RMD is 'on to it' with his "Unless diff rotation is somehow pumping".

Whatever!!

Anyway, it is just an engineering matter and I would have expected ARB to have solved it by now. With any such matters it is only testing and observing to determine the cause of the problem. Plus motivation of course!