Blocked diff breather?

[Happy]

My diff is pressurising greatly when hot. I got a snootfull of hot oil when I removed the drain plug.
Maybe the breather is blocked?
The rubber breather hose is clear but I cannot blow or suck air into the diff via the breather nipple even with the oil level plug removed.
Can anyone tell me if there is some sort of spring loaded valve in there that tends to clog up?
Thanks

 

[Happy]

Today I found that air passed freely through my friend's VT breather nipple & I imagine my VY should be the same.
Is there a hole in the gasket or a channel in the aluminium that can be blocked with gasket goo?

 

[strgas]

common issue with IRS housing was to much sealant during assembly and this would block the outlet till it either blew out with pressure or someone unblocked it . using a drill bit you can by hand twist the drill inside the metal pipe after removing the diff breather hose to clear the excesses sealant or remove the rear cover altogether and clear the pipe .

 

[Happy]

Problem solved after removing the backplate.
At manufacture the drilled breather hole had not gone through the wall by about 2mm.
Monday morning build?

 

[strgas]

hmmm must have been a Friday job that one , hooray for Q/control :banstick: