Stuck Spider Valve Gasket


Active member
Mar 23, 2015
Dallas, TX
I'm attempting to replace a spider valve gasket. The old one appears to have never been replaced, making it about 17 years old. I've read a few different threads on this but guess I was hoping someone had a magic procedure to get this thing out. I've gone at it with a flathead screwdriver but that only removes bits and pieces and leaves the part in the groove. Any suggestions are appreciated.


Mod Squad
LifeTime Supporter
Jul 10, 2012
Tallahassee, FL
I have no first hand experience with this but am pretty good an coming up with weird ideas that end up working LOL. The first thing I thought of was oil like WD-40 or even 3in1 oil. Let it sit then carefully work on it. I am thinking the oil will help relube the gasket a bit and make it easier to get out. For the groove use great care with a curved pick like these:
curved pick - Google Search

Let me know if this wild ideas works.



LifeTime Supporter
Jul 13, 2012
Dallas, TX

I had the same experience when I replaced the original Spider Gasket in my Pentair Multiport Valve a little over a year ago.

I posted in another thread (post #6 in the linked thread) about the details:

Pentair Multi-port leak

I tried a flat-head screwdriver as you did and removed part of the old gasket with it.

I obtained a set of small Utility Blades from Amazon that helped removing the old gasket: Darice Retractable Razor Knife Set, Assorted Color: Arts, Crafts Sewing

I used one of the blade tools to cut along the outer edges of the old gasket, dislodging it from the walls of the gasket channel. That helped with removing the old gasket.

As I posted in the linked thread, I wasn't able to completely remove all of the old gasket material but I've not had any leakby issues with the replaced gasket since a year ago.

The main thing is to remove the major pieces of the old gasket that would prevent the replacement gasket from seating into the gasket channel while minimizing the effect on the gasket channel with any removal tools used during the procedure.

kimkats :

The 3-in-1 oil idea sounds good. I'll try that the next time I have to replace the gasket. That should be safe to use on my Pentair Valve as the oil won't affect the plastic/poly valve material.


Well-known member
May 2, 2011
lebanon tn
Experience with gaskets that old is they are rotten and come out in chunks like you describe. The lube might help break it free from the channel but isn't likely to revitalize the rubber. Just patience and minimize damage to the channel like scoop said


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
I wouldn't try this unless you are comfortable working with the product.

Carefully applying muriatic acid to the rubber may break the bond between it and the plastic groove. It won't hurt the groove but be sure it doesn't get splashed on ANY metal parts.


Active member
Mar 23, 2015
Dallas, TX
So I think I've got most of the old gasket out...still scraping, though. The problem is the valve won't seat after installing the new gasket. I tried it without any type of glue or lube (a whole different discussion) just to see and it's like the gasket won't fit down far enough. The valve will move but it's difficult and on filter, it leaks out the waste line and the top.