Shaft Seal Leak Comes and Goes

2 years ago I had a drip leak from the bottom of the pump housing. I replaced the shaft seal and it stopped. However, since then, the drip has mysteriously returned and went away at various times. Right now it is back again. I'm thinking that changes in the priming of the basket may be the culprit. On this last episode, the pool water level got low and a low flow was causing the pump to be half-full. I shut the motor off after only about 20 minutes of limited flow, and re-primed, but the leak is back. I have tried emptying and refiling the pump a few times with no success. I'd rather not try to replace the shaft seal during the season, so I'm hoping that it will again fix itself. I don't know too much about the mechanics of a pump, but I wonder what could be happening to cause the leak to return and go away by itself. Thanks for any replies!

OK, things have gotten worse!!! Since I was able to successfully replace my shaft seal 2 years ago, and the symptoms were identical, I got a new shaft seal, and today went to replace it. When the pump was primed I started it up and the drip leak was really bad!!! I took it apart and checked everything, 3 times. No visible cracks or issues, seal and impeller look fine, but still leaking. So out of desperation I actually put the OLD seal BACK! The drip is better than with the new seal but worse than before! Oh boy!!! What have I gotten myself into. Seriously considering a new pump now, but still wondering what the heck is going on. Do shaft seals need time to form? Can they be flawed even if they look fine and fit tightly? Spring part is on impeller, ceramic part on shaft, graphite against ceramic - is this correct? Can a drip be a sign of age (pump is just shy of 6 years old - running 12 hours a day for 6 months each year?) Confused and frustrated. Please help!

Mark is the guy for this, I don't know much about pump repair, hoping he will chime in. I know this, there is an order to how all the parts go together. I know you are thinking new pump from your other post.

Speaking of Mark, he has a great article about pump run time. You don't need to run your pump 12 hours, you could get away with less, like 1-2 hours twice a day. I know you have a lot of debris that gets in your pool, so that might be why you run your pump so much more.

Thanks again swimdaddy. Hope Mark does chime in. But, while I can't open it up again for a few days, I went back over my pics of the various parts and got an idea. Although it seems the new seal is at fault, I realized I have not replaced any o rings on the pump. I wonder specifically about the pump housing o ring. It looked fine but when I placed the pump cover against it and screwed it on, I didn't feel any resistance from the rubber o ring. That's a tricky move anyway cause the o ring is not a complete circle. It has one area that angles down where the water flows upwards. I intend to replace that and the pump cover o ring next chance I get and take it from there. Still interested in any additional comments in the meantime. Thanks again!

UPDATE: So I tried new o-rings but it still leaks from the bottom. Upon closer inspection I am certain that the leak is coming from the area of the motor flange. This means that water is definitely coming through the shaft. It is happening with both the NEW and the OLD seal sets. I have a total of 3 seal sets. My original (2010) has a visible chip on the ceramic ring. The second (2014) and brand new look identical and I can see NO flaws, yet they both leak badly. The rubber that surrounds the seals fits the impellar rod snugly, and all the housing looks OK. I am baffled!

UPDATE #2... With leak getting worse despite new shaft seal AND o-rings, I decided to get a new pump. All good now. So now I am in autopsy-mode, trying to figure out what went wrong. If I can clean it up, I will at least have a backup pump. No visible flaws in shaft seal, impellar, housing, etc. yet water drips continuously from bottom (whether running or off.) Still interested in any suggestions. Curious if any of the following can damage a pump. 1. Often losing suction / pressure while vacuuming. 2. Using pump to run water thru garden hose for lowering water levels. 3. Holding water noodle over eyelet to squirt people. 4. Running pump (accidentally) with low water flow from skimmer. Thanks for the replies!