# Delta dome nut stuck



## 68bucks (Oct 30, 2020)

I have an Delta model 600 single handle shower valve that wants to drip and is getting worse. I have the repair parts but the dome nut is stuck and I, of course, don't want to bust the valve body trying to remove it. Any suggestions from someone that has faced this? I found a couple videos on the subject. One suggest heating with a torch, one guy used a dremal to slice it, one guy says tap on it, that hasn't worked. Method 1 & 2 would be an all in deal. Once you start that's it you're in it till the end, even if that means replace the valve which is then a major project with no water to the house till its done. Any recommendations?


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## Snoonyb (Oct 30, 2020)

I've yet to encounter that problem, however, should need to replace the valve, there are models available that have screwdriver, 1/4 turn shut-offs so that in the future you can just shut off a single valve, while the rest of the water feed is unaffected.


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## 68bucks (Oct 30, 2020)

Yea my last house had one like that. It was 17 years newer. All I can see is tearing a hole in the wall behind it. Yikes!


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## Jeff Handy (Oct 31, 2020)

Old Delta valves often get that corroded bonnet nut stuck on tight from minerals filling up the threads.

Take off the trim plate and try to hold the valve body with one wrench while wrenching on the nut with another wrench.

The bonnet nut does tend to get chewed up.

Also, some Delta valves can twist or even be destroyed by too much rotation force.
They are fed from behind by somewhat flimsy copper supply lines, a poor design.

If you can’t get into it to replace the guts, it’s time to change the whole valve.


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## Jeff Handy (Oct 31, 2020)

Sometimes, trying to tighten that bonnet nut a little bit will break it loose, then go back to trying to loosen it. 

You can also try squirting PB Blaster penetrating oil all around the seam, and let it soak in overnight.


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## 68bucks (Oct 31, 2020)

Thanks for the reply Jeff. The valve body is the type with the 3 thin tubes so no way to back it up with a wrench. I tried the tighten a bit to break it loose method already, no luck. Haven't soaked it yet. Looking at the replacement I'm not sure a penetrant can really get to the threads and I'm not sure how effective thay are on mineral type deposits. Those things are generally formulated for rust type issues, but I'll probably give it a try. Wonder if vinegar would work in there and dissolve mineral deposits?


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## Jeff Handy (Oct 31, 2020)

I guess you could wrap it in a vinegar soaked rag for a few hours and see if it helps.


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## Fireguy5674 (Nov 1, 2020)

The trick I learned from a plumber is to take a pair of slip jaw pliers and squeeze the dome nut multiple times moving around the nut as you squeeze and release.  It will usually break the deposits on the threads enough to allow the nut to turn.  The nut is thin enough that it deforms just a little every time and breaks loose from years of crud but returns to normal shape when you release.


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## 68bucks (Nov 6, 2020)

And the winner is.....heat. Tried the big squeeze with monster size pliers, no go. Put a touch on it just a bit and it broke free really easy. All back together and back in business. Thanks for the suggestions.


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