Breville Dual Boiler ball valve detail, pics - Page 10

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johnny4lsu
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#91: Post by johnny4lsu »

Makes sense. I feel better that they actually do more than "change one bad o-ring" and send it back. I'm sure we're in the extreme minority of BDB owners who would do the DIY fixes, so at least most people get some common failure points brought back to new.

pcrussell50

#92: Post by pcrussell50 »

Hokkay... homing in on the ultimate repair test...

I finally got an age-old, leaky valve that someone donated to me for "research", apart. It was resolutely stuck. I stripped the female hex out trying to open it. Then I stripped the chrome plating off the part, crushing it with Vise Grips and it just spun in the teeth of the tool. So today I went nuclear on it... zapped it pretty hard with a propane torch. And? Lo and behold, it came right apart. The heat completely broke down whatever thread locker was there and it came right apart. But PTFE is very heat resistant and the seals were none the worse from the heating. It was very crusted up with scale and other minerals. After a cleaning, I'm going to flip the seals, put a new o-ring in the stem, and try it out. And report back.

Fingers crossed but I'm hopeful. And this is before trying the new seals I have coming on the slow boat from China.

On Edit: I should say that the o-ring size for the stem is indeed #-008.

-Peter
LMWDP #553

pcrussell50

#93: Post by pcrussell50 »

Flipping the PTFE seals so the conical side is AWAY from the ball, is the answer.

So I took the natty looking old, donated ball valve from the post above, broke down the old thread locker with a propane torch, took it apart, flipped the Teflon seals outboard, put it back together and now I have the winner of the "ugliest ball valve in service" award, hands down. But the key part is "in service". Because it's working like a champ. I took a perfectly good, new ball valve off a perfectly good, new machine, and replaced it with this.

BTW, I had it partially assembled over night and the seals are already beginning to cold flow against the ball surface.

Woot!

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^^^ The ugly dog: (formerly) leaky ball valve donated to me from an ancient -900

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^^^ First part disassembled. You can see a conical surface already forming in what was the flat side of the Teflon washer. You can also see from the dirt on the Teflon, that I didn't even bother to clean the ball before it did this. You should clean your ball. You can see the brass underneath the plating, where I was crushing the crap out of it in Vise Grips, trying to get it apart. But it didn't work. Heat was the answer, in this case. But I took two other brand new ones apart and didn't need any heat, just the 6mm hex key. So there is lack of certainty, which way you will have to go when your time comes.

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^^^ ball will drop out (might take some tapping), as long as the groove is aligned with the tongue on the shaft, (ball closed position)

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^^^ All the parts. The o-ring on the stem is a size -008 in plain Viton, from Amazon. I put a little food grade clear silicone on it, which every espresso machine owner should have around. The stock valve uses a green o-ring, which indicates "highly saturated Nitrile, as opposed to the regular stuff which is in the plain black category, like Viton.)

Sooo... We now have another maintenance item to add to our ownership experience, in addition to periodic steam boiler o-rings, (which might be moot with the new design), and the solenoid. Because now we find that the ball valve is rebuildable. Very exciting.

-Peter
LMWDP #553

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Jake_G
Team HB

#94: Post by Jake_G »

Well done, Peter!

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lancealot

#95: Post by lancealot »

Very very nice!

I did not think it was going to separate like that. In my mind the part that has the 6mm allen key hole was a disk that came out through the female threaded end that you took off. (I hope that made sense).

pcrussell50

#96: Post by pcrussell50 »

In summary, my current theory is that leaks occur when the Teflon seal cold flows enough to become loose enough for steam to get around it. So when Rodger added his shim, it worked. When I flipped the conical sides outboard, it also worked. So I have high hopes that the 1mm OD PTFE washers I ordered off ebayZon will also work, when they get here.

As a superfluous side note, I have a stainless steel valve coming over from China as well. It's spec'd as massive overkill, but it was only $12. It will surely require some fitting. But at this point it would only be for bling.

The only thing I forgot to show in the pics is that the Teflon seals drop right out or with a tooth pick.

Also, I don't know if the -008 o-ring in the stem needed replacing. I just did it anyway whether it needed it or not.

ETA: I powered it up, fiddled with the steam on and off several times. Made a shot of espresso, then left it on powered up and pressurized while I left the house on some errands. Put a demitasse under the steam wand while I was gone. Not a single drop leaked. So far so good.

-Peter
LMWDP #553

bhennessy

#97: Post by bhennessy »

Nice job.

Curious, what holds the stem in?

pcrussell50

#98: Post by pcrussell50 »

It only goes in from the inside. You can not pull it out the top. The ball keeps it from dropping through. Remove ball, then push the stem down into the valve body.

-Peter
LMWDP #553

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lancealot

#99: Post by lancealot »

pcrussell50 wrote:In summary...
when Rodger added his shim, it worked. When I flipped the conical sides outboard, it also worked. [/i] -Peter
It also seems to have worked for me to simply tighten the seal assembly a bit with the 6mm allen key. 1 week and all is well.

pcrussell50

#100: Post by pcrussell50 » replying to lancealot »

Anything to get some seal pressure on the ball. I should have mentioned your case, too. Although eventually you will run out of thread to tighten further.

As my tightening guideline, I like to feel drag on the seals as I actuate the ball through several cycles.

-Peter
LMWDP #553