Sump leaking at lower bulk head

[gilbert23]

Do I need a new bulkhead it’s leaking at the lower bulk head not from the tank head where I sealed it. Bought it used

 

[TX_REEF]

I'd remove the pipe from the bulkhead, sand off the old adhesive and re-attach it with fresh PVC primer and glue.

 

[twentyleagues]

Do I need a new bulkhead it’s leaking at the lower bulk head not from the tank head where I sealed it. Bought it used

Why is the bulkhead siliconed? Is that a slip fit or threaded? I would replace the bulkhead. Should be no need for silicone on a flat surface.