Breville Dual Boiler Mods and Maintenance - Page 94

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fauxk

#931: Post by fauxk »

Figured I would make my first post as a thank you to the community here and hopefully help contribute something back. I bought a BDB second hand recently (2 years old, ~1500 shot counter) and immediately dove into the thing. I could hear some hissing noises when first powering it on so I took the top cover off and to my surprise (not) all the probes on the steam boiler had a slow hissing/leak. I have a bunch of o-rings on order already, #007 #010 and the smaller 5mm ones people say they put on the bottom of the probes. However they probably won't be here for another ~2 weeks and I wanted to solve this sooner than later.

So I took all the probes out and decided to lubricate the two suspect locations with food safe o-ring lube. You need to pop off the top c-clip to get the ceramic collar to slide up enough to get lube onto the little o-ring in there. Ignore the missing o-ring on one of the probes, it was left in the boiler on removal. I also cleaned up the probes with some vinegar before putting them back in.

Marked the locations to lube here for future reference:


Started up the machine and while the boiler was coming up to temp I had some hissing coming from 1 of the 3 probes, however now that its at temp its been fine for the last 1 hour or so.

I have some theories/thoughts on how these probes seal and work:

All 3 of my probes have some variation of movement up and down within the white ceramic part, even with the little c-clip in place at the top. I took a good look at the probes and I don't think this movement is a contributing factor to any leaks developing over time, considering mine go from no movement to a lot of movement yet they all leak. When you install the probe and the boiler is at full pressure, the pressure within the boiler actually forces the metal probe out. This pressure is what seals the metal probe against the o-ring in the ceramic collar. This also explains why in my case I had a small leak until everything was up to pressure and now its all seated correctly. What's interesting though is that none of the o-rings actually looked that bad, however I can see how over time the mating surface just wears out and deforms and it might just need some lube and movement to get them sealing again. I will monitor to see how this fix holds up.

BaristaBob

#932: Post by BaristaBob »

fauxk wrote:Figured I would make my first post as a thank you to the community here and hopefully help contribute something back. I bought a BDB second hand recently (2 years old, ~1500 shot counter) and immediately dove into the thing. I could hear some hissing noises when first powering it on so I took the top cover off and to my surprise (not) all the probes on the steam boiler had a slow hissing/leak. I have a bunch of o-rings on order already, #007 #010 and the smaller 5mm ones people say they put on the bottom of the probes. However they probably won't be here for another ~2 weeks and I wanted to solve this sooner than later.

So I took all the probes out and decided to lubricate the two suspect locations with food safe o-ring lube. You need to pop off the top c-clip to get the ceramic collar to slide up enough to get lube onto the little o-ring in there. Ignore the missing o-ring on one of the probes, it was left in the boiler on removal. I also cleaned up the probes with some vinegar before putting them back in.


Started up the machine and while the boiler was coming up to temp I had some hissing coming from 1 of the 3 probes, however now that its at temp its been fine for the last 1 hour or so.

I have some theories/thoughts on how these probes seal and work:

All 3 of my probes have some variation of movement up and down within the white ceramic part, even with the little c-clip in place at the top. I took a good look at the probes and I don't think this movement is a contributing factor to any leaks developing over time, considering mine go from no movement to a lot of movement yet they all leak. When you install the probe and the boiler is at full pressure, the pressure within the boiler actually forces the metal probe out. This pressure is what seals the metal probe against the o-ring in the ceramic collar. This also explains why in my case I had a small leak until everything was up to pressure and now its all seated correctly. What's interesting though is that none of the o-rings actually looked that bad, however I can see how over time the mating surface just wears out and deforms and it might just need some lube and movement to get them sealing again. I will monitor to see how this fix holds up.
Nice post. You probably know this, but those blue o-rings are made out of fluorosilicone and the size is #010. They seem to have a much longer life span than the standard silicone ones (red, #007).
Bob "hello darkness my old friend..I've come to drink you once again"

fauxk

#933: Post by fauxk replying to BaristaBob »

Indeed! I got a full fluorosilicone set of 007 and 010. Will slowly start replacing some of the 007 since my steam wand hose on the boiler is looking pretty beat.

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lancealot

#934: Post by lancealot »

My guess is that the metal slides in the ceramic by design. The metal probe will get slightly larger when it is hot, whereas the ceramic sleeve won't be effected by the temperature change as much.

I wonder if many of these leaky probe can be fixed with lube at the lower o ring. 2 years ago, I had one that started hissing steam. I put some molykote on each of them at the lower o ring and I have not had a problem since.

BaristaBob

#935: Post by BaristaBob »

However these little probe o-ring work it's an engineers dream. A little of what you guys are saying put together no doubt. I certainly can see that small o-ring tightening around the metal probe from the heat of expansion, plus the boiler pressure pushing it tightly against the ceramic insulator to create a water tight seal. As for the lube...maybe it just helps the process along, as old age and deposits work against a proper seal.
Bob "hello darkness my old friend..I've come to drink you once again"

iyayy

#936: Post by iyayy »

small ims screen upgrade.. maybe.

need some hammering to get the bolt flatter with the screen since the screen screw hole doesnt have enough angle to fit the nut properly. without hammering it'll have some play with the fit. but i think some bdb uses different screws and fit better?
mines a hex. also havnt seen/taste benefit yet, so stock bdb screen is good as it is. flow now looks ok tho, not as bad without hammering work, which tends to sometimes squirt/leaks at the edge

not as good as i got my bambino with, but works. still testing but for now im not sure i'd recommend it.
i'd recommend the one for bambino/barista models tho, if u r willing to press the screw properly.
that showering screen is tough.
for bambino it was obvious improvement in evenness on the puck, and also noticeable in taste. but unless the screw flush fit, its not gonna do a nice work.
2nd pic is bambino (flush screw with screen, similar to stock screen).



fauxk

#937: Post by fauxk »

Is the IMS screen only meant to be used with the IMS dispersion plate as well?

I was debating upgrading but wasn't sure about the plate since it changes the heat up characteristics. I had a brass dispersion plate on my Gaggia Classic and it was a massive heat sink.

iyayy

#938: Post by iyayy replying to fauxk »

in ims site there isnt really a bdb ims screen, unlike for 54mm (that still needs fiddling on the screw hole). this one is similar to gaggia i think.
there's custom plate i guess. but materials and rust is a potential issue., i believe its somewhere beneath the earlier post of this thread.
i stick with the stock plastic. dont want to mess my heat settings and warmup time.

but as i mentioned, i wasnt able to discrern any improvement, so probably not worth the price and hassle. i'll update if i find one, but dont expect any feedback soon.

dc_espresso

#939: Post by dc_espresso »

Re: the Slayer mod. I'm confused why people are advocating for Silicon Gaskets to block the hot water spigot? Gaskets have large holes in them so it seems like the water would just flow through? Also, very few are that small.. The idea of using an old bike tube with 95 degree water doesn't seem hygienic to me...

I've thought about making my own silicone mold by pouring liquid into the spigot but that seems a little painful if I decide to undo the mod. Or getting a silicone mat and cutting out a little bit. That doesn't seem like it would be watertight.

What are some food grade / hot temp products I could buy to put in there? I'm based in Australia if that's helpful

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bringyoutomyhell

#940: Post by bringyoutomyhell replying to dc_espresso »

I've read of some cutting the silicone from the lid of food containers, or like from a pan licker. I don't know if you have one nearby but IKEA kitchen aisle should have plenty of food safe stuff to cannibalize..