Hello, everyone. I just replaced the air relief assembly atop my Hayward Pro-Grid DE filter. After turning the pump back on, I noticed no leaks. However, the assembly doesn't sit flush on top of the filter housing. There's maybe 1/16" of a gap between the filter housing and the assemnbly. Is this normal? Unfortunately, I didn't take a close look at the old assembly before I removed it to see if had a similar gap. Thanks for any input.