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blocked axle breathers?


Well-Known Member
Mar 1, 2010
One of my hubs is leaking and i have heard a common cause is blocked breathers.

how can i check if they are blocked? Do i just take the breather pipe off the axle and blow into it? Can the nipple on the axle where the breather attaches be blocked too? If so how can i check this and unblock it?
It's possible it's a blocked breather but a worn seal may be more likely. Front or rear? IIRC the outlet on the axle is threaded and so you just undo it to clear it / drill it out bigger. If the pipe still has an original flapper valve on it then it's probably siezed but give it a blow and see. While you're worrying about your breathers why not extend them?
Its front axle and the leaking grease is rather runny(its dripping), seems to me that the inner axle seal has gone. The axle is overdue for a rebuild :roll:

They definitely need extending but i not entirely sure where to terminate them. So far i have heard these options:
1) terminate them in the air box, i have no idea how though
2) terminate under the bonnet as high as you can with a cheap fuel filter on the end (surely water will get in if water gets above windscreen)
3) terminate inside the body, like behind the glove box, with a cheap fuel filter on the end
4) terminate in the top of the snorkel, but this involves drilling the wheel arch panel

what is the best option?
Terminate on the bulkhead with a new OEM flapper valve is probably simplest - it's less exposed to dirt there and should keep working for ages. Don't forget to T in the transfer box breather and the main box might have a breather as well?
Instead of the 'flapper' valve, could you use a non-return valve more generally used in compressed air systems? I'll see if I can get some more info on what I am warbling on about...
You don't want a one way valve gav, it needs to let air in and out but shut down if there's much in flow or the weight of water on the cap.

Up the side of the snorkel and bent over at the top is also ok but IMO not needed.

Into the air box or snorkel is probably fine but don't ever let your intake get blocked while in water (think overhanging trees) or you'll suck loads of water into the axles.

My old 80 just had the pipe to the bulkhead with flapper valve arrangement and I never had any problems. Just replacing the valves on the existing length pipes would be ok but they'll soon get clogged up and stop working properly again which is why I favour bringing them to the bulkhead.
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Would you recommend using metal pipe, brake pipe for example for running the piping for the breathers along the chassis? Obviously you will need flexible pipe where it attaches to the axles but for protection would the metal be better?

BW aka BY
I ran some pneumatic hose, with brass t connectors, small hose clamps and lots of cable ties along the chassis leg, and up into the engine bay / bulkhead. Julian at Overland thought it was fine. About an hour job.
Yes air hose or fuel line hose is fine, just tie it up out of the way, you don't need to go to the trouble of a rigid pipe.
As its dark, do you happen to remember what diameter pipe you used?
Do you recommend using t connectors to join up the front and rear axles with the gearbox and transfer case to one valve or should i use separate valves for each?
Sorry I don't, I just pulled the existing breather pipe off and went to the pipe shop with that to get a match. I T'd it all so there was only one valve Rob.
Into the engine bay and loop at the top. While you are at it take out the fitting from the axle and clear it out, the dirt collects in the bore of the fitting under the flap.