Air in system won't let pump hold pressure (Skimmer weir stuck)

When the pump turns on, there usually isn't water in the basket in front of the pump. It runs for about 30 seconds, the fills with water and then the pump runs normally. There is big "burp" when the water starts flowing into the pool, but I didn't think it was a big deal. This morning, I turned the pump on and it operated as I described, but about 5 seconds after the basket filled completely and the pump started running, the basket completely drained of water and no water was being pulled from the pool into the pump.

I tried it again and opened the pressure valve on top of the filter, but that didn't make a difference. Thinking that the filter could somehow be clogged, I tried to backwash but there wasn't enough pressure to make it work. Next step was to take the filter apart, remove the grids, hose down, reassemble filter and start again. After all that, same problem exists. I checked the o-ring on the filter while I had it open and it was okay. I've opened and closed the clear top of the filter basket to make sure it is sealed tightly, and it seems to be.

There's nothing blocking the skimmers, and the water will flow in the system for a couple of seconds before the basket empties, pressure drops and pump starts sucking air again. HELP! It is July 4th and I'm can't keep the pump running b/c I don't know what is wrong.

Thanks

Sounds like an air leak between the skimmer and the pump.

The only things between the skimmer and the pump are a valve with a clear lid with six screws and the filter basket. I haven't touched the valve cover and I've opened and closed the filter basket lid quite a few times. I thought I had it tight enough but maybe I need to try again. When the pool is opened, the pool guys usually put some type of gel on the bottome of the lid, presumably to get a tighter seal(?). I don't really see any of that on there now. Do you know what that is and can I get it at Home Depot/Lowes or is that a pool specialty item?

It is silicone grease. Available at pool stores and probably other places. Kind of expensive but a < $10 tube will last a long time. Don't use any petroleum based grease as that will attack the gaskets. Just to add to what Carl said, even a tiny air leak can cause havoc and prevent priming and even suction. Try clesaning and lubing the gaskets and see if that helps. If it doesn't come on back and we'll work on it more.
Al

As it turns out, the problem wasn't around the basket or the pump. It was even more simple than that, but wasn't something I had come across before so I never thought to check it. For some reason, the flap {Admin => "skimmer wier} in front of the skimmer that is supposed to open when the water flows was sticking closed. When the pump basket would finally fill and the pump would start to pull water, it would only pull what was in the line back to the skimmer basket, then start sucking air b/c the skimmer couldn't pull water from the pool. The pump would run dry, then the water would slowly leak back into the skimmer until it filled, allowing the pump to run, but only long enough to drain the water again.

Anyway, not sure why it started to stick closed, but I shaved the sides down a little, put it back in and everything is working perfectly.

Thanks for taking the time to reply to my questions. PoolForum is great.