Looking for the Diff tran etc Breather

muc the truck

Well-Known Member
Sorry to bump an old thread, and to ask a silly question at the same time :oops:. Do you need to remove the original breather fittings from the diffs, gearbox, etc and replace them, or do you just add a length of hose to the original and plumb them to the snorkel airbox?
Thanks in advance,
You need to do away with the valve on the breather when extending them to the air box. A small plastic ryco fuel filter can be added inline fi you often rip out breathers doing arduous cross country . This filter is not needed but in the event you rip a breather no dust can get into the clean side of the airbox


Well-Known Member
I'm wondering whether any of you RG Colorado owners who have made these diff, gearbox, etc. extensions, can conform I have to remove the centre consul and gear shifter on my MY14 Colorado 4WD dual cab (automatic gearbox) to access the transfer case and 4WD actuator breathers when extending them? Or do you think these are well enough left plumbed into their current/factory location? (given I would only wade through deeper than 700-800 mm of water in an emergency) Did you manage to access the auto gearbox breather hose OK without removing the centre consul? Thanks.


No need to remove the centre console, the transmission breather hose end is on the top front of the transmission and the breather hose connector is on the upper front right. It is a real bitch to get at and is held up there with a zip tie as well but it can be done. I got to mine from the left side of the box, if you position yourself just right you can get your arm up to the spot. you will need to cut the zip tie to get it out. All the others are easy to get to.

Last edited:


Well-Known Member
Thanks a heap Boots33 for the quick response (and the pics which make things a lot easier to understand). The breather extensions will be
one of my next projects for the Colorado; sometime in early spring when the weather warms up a little. :)
I'll endeavour to document and post what I do to add to this thread when it happens.
Have a good week!


Well-Known Member
MY2014 Holden Colorado Diffs, Auto Transmission and Transfer case breather extensions

With a manufacturer maximum wading depth of 600mm I thought I’d raise the vehicle driveline breather extensions a little, knowing how easy it is to be caught in or have to travel through water deeper than 600mm.

On my model vehicle the automatic transmission breather outlet is situated towards the top of the gearbox bell housing at the front of the vehicle on the right hand side. Follow the transmission dipstick tube and you will see/find the hose. From the gearbox it has a short rubber tube to a T-piece, with about 800mm of hose running to the back of the gearbox as a drain. A shorter 200mm piece of hose runs to a capped plastic fitting situated behind the engine cylinder head.

The transfer case breather outlet is situated at the upper front of the transfer case on the left hand side of the vehicle. Approx. 700 mm of rubber hose runs along the top of the gearbox to a capped plastic fitting situated behind the engine cylinder head.

P9170754 (Large).JPG

To extend the transfer case and auto gearbox breathers I reused the existing T-piece at the gearbox breather outlet. I fitted a new 70mm piece of 6mm silicon hose as the existing 5/16th hose was a lose fit. I fed the end of the transfer case breather hose over the top of the gearbox and fitted it to one end of the T-piece. I then ran about 1400mm of new 6mm silicon hose from the other end of the T-piece behind the brake vacuum unit and along the r/h side of the engine bay to the air filter box. I drilled and fitted a suitable brass fitting to the air-box and attached the breather extension. End result was probably only a gain of about 200mm in height for the breather hoses, but water will have to be flowing through my air intake before it gets into the breathers.

P9170756 (Large).JPG

P9170757 (Large).JPG

P9170758 (Large).JPG

Of note is that the GM breather fittings do nothing other than provide a cap (umbrella) over the top of a breather tube which is vented to the atmosphere.

The front differential breather hose extension runs to the front bottom of the battery tray. I extended this by adding approx. 700mm of 6mm silicon hose to the end of the existing hose, running it to the rear, left side of the engine bay. I fitted/recycled one of the GM plastic cap breather tube fittings. End result is the front diff breather hose now ends about 300mm higher than previously.

P9170759 (Large).JPG

The best way to get at the rear differential breather hose is to remove the l/h rear wheel and then the inner plastic wheel arch/guard. The existing breather hose ends next to the fuel filler pipe at top of chassis height. I simply extended this hose by about 500mm by using the 5/16th rubber breather hose/drain hose from the auto gearbox. Alternatively just extend it with any suitable piece of hose. I ran the breather behind the fuel filler inlet so it sits inside the guard at a top of the tub level. I fitted/recycled one of the GM plastic cap breather tube fittings. It was about a 450mm height gain for the rear diff breather.

P9170761 (Large).JPG

P9170763 (Large).JPG

Apart from basic tools, all I needed for this job was a couple 8mm brass hose joiner fittings, a brass fitting for the air-box, 3 meters of good 6mm ID silicon hose (something with at least 3mm thick walls, not thin stuff!), and a selection of cable zip ties. Plus patience to get those couple breathers dislodged from behind the engine cylinder head (I twisted them this way and that and they eventually popped off).

I'm contemplating whether I need any form of filter on the breather extensions (?), given the manufacturer is happy with existing ones being simply vented to the atmosphere + my intention is just to get a bit more wading depth over GM's 600mm recommendation. There's no way I plan to be in water over a metre deep!
Last edited: