power steering vent ?

[lazypineapple]

Does a power resivor need to vent ?

My system is Mustang II powersteering
Tbird Rack
aluminum Steering pump (Maval Type)
9" tall aluminum resivor from Speedway

the return line to the tank is about 1/2 way up. i fill to alittle over it.
I notice when i ck level after driving, i was getting a push of air when i open the cap to resivor.
I was afraid that it might blow a seal.
So I drilled a tiny hole in the top of the cap 1/32.
no more pressure sound when cking hot.
but now.
the cap is kinda messy from a small amount of ATF coming out the hole.
if i drop the level below the return outlet in the tank, that causes aeration of the fluid and I get a wining noise from PS.
There are no baffles in the resivor.

so ? if a vent is needed, i would have to figure a way to baffle.
if no vent is needed, i can just plug up the hole and don't worry about that small amount of presure build up I here when cking hot.