Pentair Backwash Valve

[RStalls]

I have a Pentair Backwash valve that is fairly new. It leaks at the top of the shaft at the handle when closed in the filter position. However, if I move the handle just a quarter of an inch countercloskwise ( toward the backwash position) the leaking stops. Presume it is the top oring. How do you lubricate or replace it. Any suggestions

[PoolDoc]

Which valve do you have?

This pool product site has them displayed nicely: http://www.poolplaza.com/C-V-BW-PF1.html .

Here's a photo of a typical side mount multiport:
https://lh6.googleusercontent.com/-3gHktzcSIC8/Tw3JlKPE8rI/AAAAAAAAAqU/qkcT45vxjQU/s800/TopMnt_SM_2in_webL.gif

You may be able to repair it by
(1) removing the lid
(2) compressing the spring so the handle is unloaded
(3) remove pin #18
(4) disassemble
(5) replace O rings #23
(6) reassemble and reinstall.

Of course, if sand has gotten into the stem, and scratched the sealing surfaces, O-rings won't fix things.

[RStalls]

I just have a push/pull backwash valve. I noticed today that it also drips a little out of the drain line even though it is in the filter position

[PoolDoc]

If your valve is like this:

https://lh3.googleusercontent.com/-htlsa4tvrYc/Tw4plMnku2I/AAAAAAAAAqs/W-PdPte1684/s800/PushPull_schem_webL.gif

then here's your item list:
Item Part Number Description
1 51013811 Valve stem complete w/ handle
1 51014311 Valve stem complete w/ handle, brass
2 51013011 Nut
3 51013500 O-ring, nut
4 51013111 Reducer bushing, 2 in. male x 1-1/2 in. slip
5 51003100 O-ring, cap
6 51012911 Cap
7 51014011 Body, with bulkhead fittings 8.0"
7a 270052 Body, with bulkhead fittings 7.5"
8 51005000 O-ring, valve stem, 2 in., 2 req.
9 39102900 O-ring, bulkhead (2) * 8.0" Model only
10 51013500 O-ring, bulkhead (2) * 8.0" Model only
11 274494 O-ring, bulkhead (2) 7.5" Model

Keep in mind that it's still true that if the surface the O-ring seals against has been damage, simply replacing the O-ring may not help.

If you have another valve, you may have to wade through the PentairPool valve manuals: http://www.pentairpool.com/pool-owner/manuals/section.php?s=51

Pentair bought both American and StaRite, and has their slide valves. I don't remember whether PacFab (what Pentair used to be) had a slide or not, but I didn't see one listed.