Questions about breather hose

[cryptobiotic]

My Breather hose is just hangin not plugged in to the rear diff, it is about 100$ to repair, I am just wondering what does this breather hose actually do?? /forums/images/graemlins/k5.gif

 

[Shaggy]

<font color="green"> $100 to repair? Dude, it's a hose that plugs into the diff, how much easier could it be? WOrst case you'll need to tap the diff and thread in a new nipple, but even that is dirt simple. The hose is to allow for pressure in the diff to equalize with the atmospheric pressure outside, since when the diff heats up and cools the air expands and contracts. Without the vent the pressure would have to blow through the seals. </font color>

 

[95 Silverado]

All engines, transmissions, and differentials develop pressure inside their housings from the motion of the parts and the heat produced inside them, this causes the lubricants to expand, the vent allows the pressure from the expanding materials to escape, preventing your seals from leaking due to the pressure, cars don't usually have hoses attached, but they have breathers just the same, the hoses are used on trucks, especially 4X4's to get the breather at a higher level to prevent water from entering the breather when four wheeling or traveling in muddy conditions or deep water.