I have experienced a suction side leak on and off for the past year. I tried everything to find it, short of replacing all the pvc joints. I knew it was close to the pump because the leak would lessen when I ran a water hose over the joints. Unfortunately, however, but I could not detect what joint was leaking. Finally I bought a tube of epoxy putty and starting at the pump,with it running, I applied the putty around each joint. On the fourth joint the air leak disappeared. I used the marine type epoxy putty but think any of them would do the job. Glad to finally take care of my suction side leak.