Tub spout still leaks after shower cartridge replaced

[Cabin_Mama]

We just replaced the shower cartridge in our Delta 1400 series handle. We used an authentic Delta RP19804 ... two of them, in fact, because after we replaced the first, the tub spout still leaked. So we thought it was defective and put a second one in. Tub spout STILL leaks, even a little worse now.

I'm confident it's not the cartridge at this point. We also cleaned the housing each time we did this, with vinegar and a toothbrush, and flushed it out. I ran my finger along the housing openings and nothing felt jagged or messed up. Both times the cartridge seated flush. We've also done this successfully on the other shower in our house.

Please help! What on earth else could be wrong here?

 

[Breplum]

The cartridge has just rubber "seat" gaskets and springs, classic Delta parts. take it apart to examine them.
they are the parts that prevent water passage when the metal plate rotates.
Very straightforward. Call Delta support to see if they have anything to suggest. Delta parts are lifetime warranty...hope you got the cartridges from them.

 

[Sponsor]

 

[Cabin_Mama]

Thanks, @Breplum. If the gaskets and springs are fine, what else could it be? I would find it odd if both cartridges had the same issue..
I might take your suggestion to call Delta.

 

[Cabin_Mama]

I saw elsewhere on the internet someone suggested stretching the springs a little! They didn't say why, but I assume with the idea that it would push the gaskets out a little to create a better seal with the metal plate. Does that sound plausible?

Others mentioned that plumbers' grease on the O-rings solved this problem for them, but I used a good amount it both times.

 

[Cabin_Mama]

UPDATE!!!! I took the dang cartridge back out, twisted it open, and took out the seats and springs. Then I carefully stretched the springs about 1/8 inch longer with pliers and a flathead screwdriver, and put the whole assembly back together and into the valve body. SO FAR NO MORE LEAKS!!! I almost cried with relief. The leak with the new cartridge was SO bad before I did this.

SIDE NOTE... the cartridge would not go back in nicely, no matter how much plumber's grease I used or how clean I had the valve housing. So I swapped the fat new o-rings for the thinner ones from the old cartridge and voila, slid right in. (They were still in fine shape, from what I could see). I was 30 seconds from calling a plumber before I tried this.

I had called Delta support yesterday and while they were very friendly, they could not in good conscience agree to me stretching the springs. I get it. BUT IT WORKED!