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latwelve

Remote Breathers - Series 3, Just double checking my logic..

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Hi all, 

I've got a 74 plate series 3. 2.25d

I've had a search around and it seems that replacing the 2 breathers on the axle and adding 2 breathers (1 onto the gearbox and 1 onto the transfer box?) seems like good logic to help reduce the pressure build up and leakage of oils!

It seems a lot of people use pneumatic connectors - are these just standard 1/8"  ones? There are kits on ebay for £50 including a manifold but I'd rather just buy the connectors and not have a manifold.

My logic is that I dont mind running all the breathers to a high point (all the front ones into the engine bay and probably the back axle up high in the underside of the tub?

The manifold seems only sensible if you're doing it up to a snorkle and I dont like the idea that the pipes all join (more potential for blocking?).


My question is... am I on the right track? I know I have to drill 2 holes on my boxes but other than that am I good to go? Do I need to bend the pipes over or mayb fit a 90 degree elbow when they are in the engine bay to prevent anything falling into them? or put them into an area with a cover over the top?

Also is there any best practices to making sure they stay clear? can I blow an airline down them periodically?

Thanks

 

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The axles have breathers on the top of the main tubes, but these can block up, so remove, soak in petrol and check the ball bearing inside is free to move, then refit.

The gear box and transfer box already have breathers.  They are pin-hole drillings in the circular cap behind the gear stick and in the square plate atop the gear box tower on early units and plastic grommets with a small slot in the same locations on late units respectively.  They can clog up, especially the transfer box breather, and particularly if the top of the casings are covered in thick grime.  The transfer box breathes through a (roughly) 1/4" slot in the mating face of the transfer box, and up into the tower at the back of the gear box case.  If too much sealant is used when joining the two boxes, then this slot can be clogged, so only use a gasket and grease, not sealant on this joint.

Remote breathers are unlikely to be a big improvement in how much oil they stop, except on Fairey overdrives, but they can help reduce water ingress from wading.

Transfer box breather slot: https://www.google.com/search?q=land+rover+siii+gear+box+casing&safe=active&rlz=1C1GCEA_enAE834AE834&source=lnms&tbm=isch&sa=X&ved=0ahUKEwje39-whqTgAhX98OAKHdoQDvwQ_AUIDigB&biw=1280&bih=743#imgrc=6gVhEEzjoeZnEM:

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You can of course make checking and cleaning breathers part of your maintenance schedule, but you would also be following a well trodden path if you chose to fit extended breathers, and forgo that chore.

Regarding 'terminating' the open ends; when LR fitted extended axle breathers to the 38A Range Rover the upper ends were moulded with a 180 degree turn, about a 2" diameter bend, followed by an inch or so of straight pipe facing downwards. They were at the top of the engine bay, held against the rear bulkhead.
I see no need to blow down them occasionally, especially NOT from the open end towards the mechanical bits. Let the 'breathing' of the hot air do the work of discouraging spiders, flies etc.

You haven't included your general location in your profile, so I'm assuming UK residency.
Owners in areas of the world with a higher density of 'spiders and insects', and / or dust, may have different advice to offer regarding cleaning, but I regard extended breathers as maintenance free, after an initial early life check to ensure they aren't chafing anywhere; It's a little galling to have an extended breather terminating at a high level only to find it has a hole in it at a low level!

Regards.

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Thanks guys - I'm not really doing any wading but it was more to try and minimise leaks.

I think the pin hole in the gearbox is too small to do any substantial pressure relief so maybe I tackle that first. I need to take my axles off anyway for a service so I'll have a think on the breathers for them too. I just dont see how a small pneumatic hose isnt going to block almost instantly by oil being spat up from the inside?

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For the axles disco and Defender axle breather banjos have the same thread as series axle breathers so you can retrofit a pair of breathers from a scrap disco/defender.

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On 2/5/2019 at 4:18 PM, latwelve said:

Thanks guys - I'm not really doing any wading but it was more to try and minimise leaks.

I think the pin hole in the gearbox is too small to do any substantial pressure relief so maybe I tackle that first. I need to take my axles off anyway for a service so I'll have a think on the breathers for them too. I just dont see how a small pneumatic hose isnt going to block almost instantly by oil being spat up from the inside?

Don't forget, the heating and cooling of the transmission is slow, and thus so is the expansion/contraction of the oil and pressure change of the air inside.  The only exception to that is wading, and even then, the small breather will cope as long as it's clean.  The designers did calculate these things.

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