My ARBs have been pretty much maintenance free. I did have to replace the pressure switch after 5 years. The $7 dollar replacement has been great for the last year. I also had an oring on the seal housing fail. I cant blame ARB for that though as my rear ARB has seen many different gear setups, so it has been in/out so many times that it just plain wore out. $16 replacement if I remember. The poly tubing that comes with ARB is a hardened material that can take some serious abuse. It is not a weak, thin-walled tube.
If you are blowing out oil from the solenoid, it could be a # of things:
Plugged vent line. Your diff builds pressure when things are moving. If it cant vent easily it will take the path of least resistance.
To much gear oil ( I am guilty of this). The ARB takes up quite a bit of space in the diff. You fill with a bit less oil because of the space it takes up in the diff housing.
Not enough preload during the install--Gear oil can weep past the seal housing and be pushed thru the tubes.
Inadequate drainage. ARB specifically calls this out in their instructions. Some axles didnt have enough drainage, so now with a bigger carrier it fills an axle tube which results in a blocked line. Which again, path of least resistance, goes back thru the ARB line. Most likely this is your issue.