Backwash Valve Replacement

Jul 4, 2010
31
Apple Valley, California
Surface
Plaster
Chlorine
Liquid Chlorine
My slider backwash valve is stuck. So stuck that I can't even turn the handle. So, I am planning on replacing it with a "Pentair 261152 Multiport Valve Kit 2in. Threaded" valve.

First, I want to know if this is the right valve for my DE filter:
261152 Pentair Multiport Valve Threaded.jpg - Shared with pCloud

My DE filter is an old PAC-FAB FNS 60.
20191125_115459.jpg - Shared with pCloud

Next, I'm just asking for some advice on how to properly do the job, and any helpful tips for doing the job correctly the first time. I am fairly good with hand tools and small DIY jobs around the home. I just don't want to screw this up.

Here's a link to other photos of my pool equipment:
Backwash Valve - Shared with pCloud (If this link doesn't work, please let me know.)

Thanks in advance for any help!

Jerry, the poollizard.
 
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Well, I finally got the core out of the casing. What I did was, 1) First I drained the filter tank, 2) then I disconnected the tank from the backwash valve, 3) Then I sprayed some WD-40 into the valve's both ports, 4) I let that soak a while, while I cleaned the filter grids, 5) then I reconnected the tank to the valve to give it some stability, 6) then I tried one more time to get the core to turn, and by golly, it turned! So then I just kept pulling and turning and finally it popped out.

Here's a pic of the core plunger:
20191126-0412571409.jpg - Shared with pCloud

It looks to me like the lube I had put on it back on October 23rd, got all gummy and stiff. I used a well known store brand "Pool & Spa Lube".

What would you do? Would you just get a whole new valve, plunger and all? Or would you just clean up this one and use a different lube on the O rings? Maybe even get a new set of O rings.
 
Well, it's come to this. I'm either going to get a whole new valve, plunger, casing and all, or I'm just going to replace the core plunger.

This old plunger of mine has a few problems from when I replaced the O rings back in October. I bunged up the cotter pin getting the handle off of the shaft so I could replace that small o-ring that's just under the top plate.

So now the question is, should I replace the whole thing, or just the plunger?

I'm not real excited about redoing the plumbing for a whole new valve. I think I'm going to get a new plunger assembly.

But what lube should I use? I'm afraid to use the same lube that I already have, for fear of the same thing happening again.

I've already checked my local Home Depot and Lowe's, neither of them have ZerO lube.
 
New O rings and the right lube should get it going.

Pool Lube is used to seal O rings and make them water tight. They are not good for a sliding O ring like here.
 
Well, as it turned out I had to replace the whole piston assembly. I must have cracked the original one, because even with new o-rings it leaked out the top. New one installed and working fine now.

Thanks to everyone who replied and left tips. It all helped.

Happy Thanksgiving to all!
 

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