Pentair Diverter Valve Leaking into Waste Line

[GAR1]

I had my sand filter replaced with a cartridge filter several seasons ago. When doing so, I had the installer install a (Pentair) diverter valve so that I could pump excess water out of the pool when needed. The diverter valve is on the pipe coming from the pump basket and diverts the flow either to the filter or to a waste line. This year after opening the pool, I noticed that when the diverter is in the off position for the waste line (that is, the water is flowing to the filter) water continues to drip from the waste line. I tried adjusting the valve slightly, to see if that would stop the dripping, but it didn't. I searched the forums for a similar problem but only saw threads discussing the issue of water leaking from the waste line when there was a multiport or a push/pull type backwash valve involved. The only thread I saw where there was an issue with a 2/3 way diverter valve, it appeared that the water was leaking out of the valve itself and not the waste line.

My question is: Do the same issues/solutions identified in the other threads concerning water leaking from the waste/backwash line when there is a multiport valve or push/pull type valve also apply with the Pentair diverter valve I have? Specifically, could a damaged O ring be causing my problem, or do I need to replace the diverter assembly? If it could be an O ring, which one is it? There are two O rings according to the parts listing for Pentair 2/3 way valves (See http://www.poolpartsonline.com/p-174-pentair-compool-diverter-and-check-valve-parts-15-and-2.aspx).

Also, I know I should shut the system off before I take the valve apart to replace the O rings and/or the diverter assembly. Should I also close the skimmer and main drain lines? Will water leak out of the open valve from my filter and, if so, is there a way to prevent that?

Thank you in advance for any advice.

 

[Richard320]

Welcome!

Looks like you need parts 7,8, and 9 to overhaul the leaking valve. Click on 9 and study the larger image. That white bead is what seals. I bet it's torn.
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Update

If the valve is above the pool surface, it should just drain back to the pool when you start loosening screws. If the pool is above the filter, you'll need top plug lines somehow. .

 

[GAR1]

Thank you very much. That is kind of what I thought. It looked to me that if the O rings were failing that it would leak out of the valve itself, rather than the waste line. However, I wanted to confirm that in case I could get away with buying a couple of dollar parts, instead of a $45.00 + plus part, which is more than the whole valve costs at Amazon.