Thread: replacement front diff breather Disco 3 and 4

One of the many things I love about this forum is the little 'to do' lists which appear from time to time, just like this one. Thanks all.

So, when I checked mine it was already cut off (at least someone followed the factory instructions and did so at the correct angle) but didn't put a replacement filter on (or maybe it came off). No idea how long / km's without a filter. Haven't been into any mud or wet though, just heaps of outback dust.

I went with Disco-tastic option of a small fuel filter and section of line, from Auto shop.

Not sure how successful the irrigation / dripper idea will be. Don't these thngs just flow one way, with a rubber washer inside to stop dirt (possibly restricting air flow) from being sucked back in.

Originally Posted by Ozzy119

Not sure how successful the irrigation / dripper idea will be. Don't these thngs just flow one way, with a rubber washer inside to stop dirt (possibly restricting air flow) from being sucked back in.

They don’t exactly ‘flow’ at all. They allow air in and out to cater for the expansion and contraction of the air within the diff. The volume of air moving through it will be tiny, but it’s important none the less, else the seals will take the brunt of it.

Originally Posted by Ozzy119

One of the many things I love about this forum is the little 'to do' lists which appear from time to time, just like this one. Thanks all.

So, when I checked mine it was already cut off (at least someone followed the factory instructions and did so at the correct angle) but didn't put a replacement filter on (or maybe it came off). No idea how long / km's without a filter. Haven't been into any mud or wet though, just heaps of outback dust.

I went with Disco-tastic option of a small fuel filter and section of line, from Auto shop.

Not sure how successful the irrigation / dripper idea will be. Don't these thngs just flow one way, with a rubber washer inside to stop dirt (possibly restricting air flow) from being sucked back in.

I have to agree with what you said - from a suggestion about checking your filter to the "factory" fix, then to other fixes.
All very worthwhile, and thanks to everyone who participated.
Alan

Originally Posted by Ozzy119

Not sure how successful the irrigation / dripper idea will be. Don't these thngs just flow one way, with a rubber washer inside to stop dirt (possibly restricting air flow) from being sucked back in.

There are several dripper varieties to choose from in my box of tricks. They all screw in which is handy. All are open to flow both ways.

The style I chose can vary the flow by turning the cap to completely closed. I used a middle setting and checked by sucking/blowing in it.

The flow comes up through the centre pipe goes around a spear through two 180 degree turns in the head so is a better design than the original in my opinion.

At least now I can screw the top off from time to time to blow it out.

As mentioned, you could very easily extend the hose around to the battery box and have the dripper head in there through a small drill hole. That would bring the job up to $1.

Hi Guys just checked my09 D3 and has the original filter. Cut it off and you guessed it, it was blocked solid could not suck or below any air through it. I went with the supercheap version, so now back in buisness. I seem to recall my first 05 D3 did start too weep through the seals maybe this could have been the culprit that caused this problem.
Cheers

Pulled my new genuine replacement apart (see image). Made by the Gore company (think Gore-tex). It’s a much larger surface area filter with extremely fine filtering (just look at it), plus by the restriction when trying to blow through it. And yes, $50 to my door

Keep in mind guys the volume change as things heat up and contract...

It’s actually quite significant even from 20c to 40c.

So the flow through that breather when you hit cold water will be significant, poor flow will lead to seals drawing in cold water when submersed *and* conversely the common oil bypassing the seals as it warms up issue is a result of the expansion and lack of flow..

Originally Posted by Tombie

Keep in mind guys the volume change as things heat up and contract...

It’s actually quite significant even from 20c to 40c.

So the flow through that breather when you hit cold water will be significant, poor flow will lead to seals drawing in cold water when submersed *and* conversely the common oil bypassing the seals as it warms up issue is a result of the expansion and lack of flow..

Since all the old style breathers people have removed have been totally blocked the saviour must be a very tiny air volume as seal and diff failure rates should almost be on an epidemic level otherwise.