Diff Breathers

[SandRunner Member Find all posts View Profile Close SandRunner]

Well, finally got the last of the breathers done yesterday morning. Not that hard at all when following these instructions. Thanks guys. But there is no hope in hell I will be able to replace the hoses to the factory plastic clips on top of the transfer box or bell housing. Zip ties will have to do.

Did anyone get the hoses back into the factory clips after doing the extensions??

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

I tried to fit the 1/4" hose back into the factory clip with the others cable tied to that and failed miserably. That is why there is blood on the conduit in one of the pics! I dropped it all back down and ran them up individually on the best shortest route and cable tied them to whatever was in the way. Realistically the clip is in the wrong location if you run the breathers to the same side as I did.

[rwo Advanced Member Find all posts View Profile Close rwo]

Its finally time for me to tackle the diff breathers. Where have people run their cable extensions from the rear to the front? I have stuffed around or the last hour but cant really find anywhere to run it without cable tying to fuel or brake lines, just wondering what others have done...

[craigm Addicted PP Member Find all posts View Profile Close craigm]

That's exactly what I did rwo. I ran my breather tube from the rear in split tubing all the way and pretty much followed the fuel lines between said lines and the underbody, ensuring I ran under the exhaust shielding also, and up to the passenger side on the firewall.




Loop allowed at the Diff for articulation

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

rwo I cable tied to fuel lines, there is also a vacant support up front, and then ran over the chassis to the rear diff. Cable ties onto whatever was convenient and leave a loop for axle articulation.

[rwo Advanced Member Find all posts View Profile Close rwo]

Thanks for the response craigm and mjrandom, so cable ties to solid fuel lines are not likely to cause any problems later on (rubbing through or something), the lines look expensive to replace with the amount of shit that would need to be removed not mentioning the potential problems that may be caused by a ruptured fuel line in the middle of nowhere?

I am using 1/4" rubber fuel hose for my breathers.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Doubt there would be any problems as there is no movement. Just give yourself enough loop or slack for the diff to move without tearing the hose off the ties or pulling the hose off the fitting into the diff. The rear diff is the only one you need to give some slack, the rest can be cable tied and run straight.

[Nightrod111 Member Find all posts View Profile Close Nightrod111]

I did my rear diff breather yesterday.
When i took the standard rear diff breather off it sucked in alot of air. My car has only done 5000ks so i doubt it was blocked It seems to be a one way valve. This makes sense so the diff doesnt suck in water etc but im sure the pressure isnt doing the seals any favours.
I also have front and rear lockers so its good to know that i have 0 pressure in the diff when my lockers arent engaged.

[JCG Lurker Find all posts View Profile Close JCG]

I did my rear diff breather yesterday.
When i took the standard rear diff breather off it sucked in alot of air. My car has only done 5000ks so i doubt it was blocked It seems to be a one way valve. This makes sense so the diff doesnt suck in water etc but im sure the pressure isnt doing the seals any favours.
I also have front and rear lockers so its good to know that i have 0 pressure in the diff when my lockers arent engaged.

Don't you mean it allowed pressurized air out as you removed it?

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

No, they suck!

[JCG Lurker Find all posts View Profile Close JCG]

No, they suck!

What creates the suction?

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

The diff gets hot, hot air expands and the cap allows the air to escape. On cooling the cap is pushed back onto the factory breather thing by the higher pressure air outside and thus there is a vacuum however slight in the diff when cold. I have done breathers on my 90, 120 and 150 as well as Prados belonging to others. All the same. So if you extend the breathers don't reuse the factory caps.

[Whitey1 Advanced Member Find all posts View Profile Close Whitey1]

So if the factory breathers don't let anything back in, why bother going to the trouble of extending them?
Is it just so that normal(?) breathers/filters can be used to allow the diff etc to breathe both ways?
Or am I missing something?

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

If you are in 500mm of water which is about the factory wading depth the rear differential and gearbox and transfer case breathers will all be submerged. If you go in with a hot driveline the sudden cooling (drops pressure rapidly) can allow water to enter through the seals if not under the breather caps. Extended breathers let air rush back into the driveline components and it is unlikely that water will force its way in. Remember the oil seals are designed to keep oil in not water out.

[Whitey1 Advanced Member Find all posts View Profile Close Whitey1]

Ok, that's what I thought but some people were just extending the lines and putting the factory breathers back on, so that's why I couldn't see the point because the factory ones don't allow air back in.