pcrussell50 wrote:No diagnosis necessary here. When the steam wand itself is dripping continuously (and not just a few drops of condensation coming out from sitting), the only possible cause is the seals inside the valve itself. Fortunately, the valve is of a serviceable design rather than a disposable type. The seals need to be flipped over to expose a new sealing surface: (this is not an o-ring issue)

video

Now... the steam valve is spliced into the system by o-rings. And these o-rings also need to be replaced every so often like the others. But they are not part of what causes a drip through the wand.

-Peter

Peter, having stalked this page for a bit I see you are the authority on the BDB . I just recently noticed dripping even if ever so slow from the portion of the steam want socket where it attaches to the machine. That is separate from the tip drips I already get and probably should do the seal flip but the socket drip is maybe more concerning? any suggestions?

As I fiddled more with my Oracle Touch (also probably identical to the Barista Touch), I discovered that on the two latest touch screen enabled machines from Breville (Sage), they have separated and regulated the pump power / flow rate into the following. I cannot change PI settings, sadly, it defaults to 55% pump and 7 seconds. 980 non touch unit have more leeway. There's just probably a very small variance in my measurement below compared to others because of the voltage and frequency (my EU unit is 220-240 50/60hz but is operating in 220V/50Hz grid). I don't think the unit PCB software takes into account of this difference.

Duration control mode (espresso and milk based drinks):
- Manual Override, pump reach 55% (4.4 g/s) in 3s, reach 100% (8 g/s) in 9s and hold this onward
- Duration Program w/ Pre-Infusion (Single/Double shot), 1st stage (pre-wet): 7s of the pump ramping from 0% to 55% (4.4 g/s) -> 2nd stage (rise): another 7s of the pump ramping from 55% (4 g/s) to full power (8 g/s) -> 3rd stage (hold): pump at full power (8 g/s)

Volumetric control mode (americano and cafe crema):
- Regardless of the size of the drink I set, the pump is at straight 75% (6 g/s)
- Default Small is 130g, Medium 165g, Large 200g

With these known, and the fact that I cannot program the PI like previous models anymore, how should I think and work around the fixed pump curve (duration program mode w/ 7s pre-infusion)? Lately I'm aiming my time to filter (beadings at the bottom) to be at when the first 7s stage ends, but I'm not quite happy with the shot, I can clearly see that given the appropriate grind size and yield (1:1.5 medium beans), it just doesn't saturate the whole puck, there are blotches of area underneath the basket that don't have any drippings in order to form into a cone of stream. There's clear sign of channeling in taste, there's no spritzing. My puck prep is consistent, single dose, Duomo WDT, Force Tamper, BPlus Screen.

There's also a newer 304 dispersion block that's designed closer to OEM than the previous one others and I shared here, it seems like it should works better, because previous 304 block doesn't have the raised center part like on OEM on the rear side.

newer 304 block


previous 304 block


I came across Breville patent filed for their pump control and flow rate calculation if anyone wants a read.

p.s: I have a suspicion that because of some known pump failures due to Breville's modification to pump power supply signal is why they removed the adjustable PI completely from Oracle and Barista Touch..

Is it possible to replace Bes900 PCB with 920 PCB to get time based shot control and higher steam temperature?

I think it will work as all the parts are the same except for the 920XL has the front drain screws. You have to make sure the voltage are the same.

longpvo wrote:There's also a newer 304 dispersion block that's designed closer to OEM than the previous one others and I shared here, it seems like it should works better, because previous 304 block doesn't have the raised center part like on OEM on the rear side.

newer 304 block

previous 304 block

Where can one pick up the newer 304 block?

New here !

I have done gs3 mod with hot water reroute to the water tank, work nicely

Had some questions

1. Anyone have a custom knob for hot water and steam knob ? Just wish that the hot water knob had the similar look like the steam knob so it easier to muscle memorize on flow control.

2. I read somewhere about AFLAS o ring that are great one. Which size of it required to swab in the machine ?

3. About the pump, I think I read somewhere in the thread that there are post about the pump code. Anyone recognize that ? Since it had a code that told the same size of pump with the different between them. Also to anyone who done the brass OPV and new pump changing, do you guys had a list of the stuff we need ?

Thanks in advance

TCapone wrote:Where can one pick up the newer 304 block?

eBay Au

There was a post with a tape measure mod, sticky tape? For the water knob. Someone posted a link on Amazon but the search feature on this site is borked as I can't find it again, either in this thread or slayer thread and not going through 100+ pages again lol.

Anyone know which tape was used to have thr markings on the knob?

I tried a "spro-over" with my BDB and it gurgled the entire time it was preinfusing at 55% for 90s - afterwards it overheated and threw errors 8 and 10.

I've always felt there was some air in the system (since it takes a little bit of time to get through gurgles when the pump comes on) and it seems like this operating condition exacerbates that.

Running the water tap cleared the high temp condition and was back to "my" normal. Has anyone had any experience with similar observations on their BDB?

As an additional observation, the water comes on much strongly for example if I run the water tap before pushing a shot button, also leading me to think there's air getting pulled into the system.