Where does a 123 wagon relieve vacuum pressure for the gas tank?

[CEC]

I have a 1985 230TE wagon. I was getting a gas smell in the car so I replaced all of the fuel hoses. That part worked great. I no longer have any smell. The issue is I am getting quite a large vacuum created in my tank. Is there a valve somewhere on the 123's to allow air into the tank to prevent this problem. After looking through all my manuals and parts books I can't find this vent. Anyone out there have an idea where this valve may be? I know where the valve is to go to the charcoal canister but not sure where air would be allowed in to equalize tank pressure. Just to let you know how bad it is getting. It is real hard to pull off the gas cap now and I think it has damaged my fuel sender as it no longer functions correctly. I have read of tanks imploding on 123's so I wanted to correct this before it went to far.

Chuck
1985 230TE 5 Speed