We just moved into a house with a pool and it's been a long while since I have dealt wih pools. We just replaced our pump, (Hayward, 1 1/2hp) and it's got a dream line sand filter (we did not replace the filter, looks to be older). We got everything hooked up and it worked fine for a few weeks...until yesterday. Went out to vacuum yuckiness out of the bottom of pool and backwashed, and pump would not prime when it was put back into filter position. There is a clear tube running from pump to filter and i can see it's full of air. I have no manual release on filter to release air, and pump will not prime. I noticed there's a tiny hairline crack above where my pressure gauge goes in my filter so we put some epoxy on it last night hoping it would hold...it didn't. My question is, is that tiny crack really causing all of that air in my pump? I have researched buying a whole new valve and everything for my filter, but after just buying a pump, I'm hestitant to do so. Any help at all would be appreciated!!