Infamous Delta 600 old shower valve worries

[FixingThings]

Hello,

I have this 24yrs old Delta 600 series shower set that has a slow leak through the spigot.
I already bought the rubber and spring valve parts that should fix the leak, but I have had quite a bit of trouble trying to remove the dome that houses the valve. I have tried PB blaster overnight, Wd40 and I am using a pipe wrench and then tapping the wrench with another wrench to try to unscrew it as seen on some videos who had success.

I stopped because I chickened out really since I don't want to bend the 3 copper pipes that feed the valve, but it seems that I managed to move it a bit. Before I continue tapping at it I wanted to ask you guys if you see this method as too risky for the condition of this valve as shown here on the pics. I don't want to mess it up and break the pipes and then have a super expensive repair, but It seems that I got it started.
Would you rather cut the dome open with a dremel tool and a circular saw? then put a new one?

Also, there seems to be a lot of green on the pipes indicating there was a leak at some point, but I could not find any moisture or water or any indication that there is a leak now. I used a paper towel to touch around the valve and look for moisture and nothing.
I do see that the bottom behind the shower has some black on the wood floor, but could that be from an old leak. I don't see any moisture where the long pipes meet the joists. Shouldn't that area be wet or rotted or show sings of water sliding through the pipes there if there was a leak that persisted?

Lastly, when I unscrewed the front Delta round plate, I heard that something dropped. It seems that there was a 2x4 wedged in between the front of the valve and the back of the plate? Should I attempt to put another 2x4 back and where would it go? On top of the valve I assume?

Here are some pics (smaller in size this time)
Thanks

 

[hj]

You have already "twisted" the supply pipes. The slot should be vertical, NOT on an angle.

 

[Sponsor]

 

[FixingThings]

You have already "twisted" the supply pipes. The slot should be vertical, NOT on an angle.

Hi, that's what I thought too and reason I stopped. However if you look closely the metal ball inside has a diamond shape on the tip that shows it is still straight. Also, the white plastic thing is being held by the dome and and it seems to just have rotated to the left with the dome as I was trying to unscrew it. If I would have twisted the pipes then the metal ball's tip would have also rotated. This is just my observation, what do you think?

 

[Terry]

My last replacement.

Homeowners sometimes twist them up pretty badly.

Some comments from plumbers.

Looks like it already is twisted counterclockwise. I use a torch. Sometimes the cam washer will start melting. Not to much pressure on the channel locks. And it should come loose.
Richard

Pb blaster. Amazing stuff.
Aaron

I wrap a piece of emery around it real tight and turn by hand.
Jimmy

Cut the nut off. They sell replacement nuts.
Travis

I use a hose clamp. You apply even pressure all the way around. Then turn with channel locks.
Kyle

Dremel and cutting wheel, just make sure you have a bonnet nut for the replacement. I have had to do this on the newer Deltas pressure balance valves.
Alan

Hacksaw blade works, as long as you can replace the nut.
Paul

Opposing hammers...tap tap tap all the way around it a time or 2 and should come right off.
Pat

Pb blast let set and tap on it.
Jesse

The trick is not to egg the bonnet with your channel locks. Give it a few taps and go easy on it. Once you bend the tubes, you're down the river in a raft without a paddle. Or something like that.
Mike

A little heat with a torch on the bonnet to expand it and then very carefully without egging the bonnet unthread with pliers.
Terry

Chainsaw!
Kenneth

 

[FixingThings]

Thank you so much for the pics and tips!!!!

Tried the PB blaster and tap on it. I just chickened out when I saw the white cam washer rotate.
Do you suggest I attempt to continue with the pipe wrench and tap tap tap again or use a dremel and cutting wheel at this point?
I figure the white cam rotating means I already started it right and I should have a good chance at it now?

Thanks again!

 

[Terry]

You've already rotated it. It may still be holding, but the handle will be angled over. I think at some point, it will need to be replaced.
Many of the tips listed work, but they also work better "before" the dome has been egged with a wrench. I normally use a little heat on the dome, tap it a few times and gently unthread it. I like the tip about the hose clamp, and the one where it's sawed off, which I haven't tried yet.

And then there is this page on it.

https://terrylove.com/forums/index.php?threads/delta-600-shower-valve-replacement.70932/

 

[FixingThings]

Got it.

I will give it another shot tomorrow with a torch lighter I have. I assume that would give enough heat to help with the rotation and use the pipe wrench and tap it.

Should I try to put a 2x4 between the tub and the top of the valve or close it all without anything there.
You have no idea how much I freaked out when I heard something fall when I unscrewed the face plate.

thanks again