Breville Dual Boiler Mods and Maintenance - Page 61

#601: Post by **BaristaBob** » August 4th, 2021, 9:02 pm

luvmy40 wrote:I just received that IMS screen, SS dispersion block and Cafelat gasket.
https://smile.amazon.com/dp/B095K94F7N? ... ct_details
After a couple days, I can say it was well worth $52.43 USD
The SS block may not be necessary but does not seem to have any detrimental effects on my shots.
The Cafelat gasket should be a required upgrade. No more twisting the portafilter to 4:00. it locks up tight at 6:00
I have no opinion yet on the IMS Screen. It certainly does it's job well, whether it's quantifiably better than the stock screen, I cannot say.

Is the ss screen holder the same thickness as the oem screen holder?

August 5th, 2021, 7:41 am

I didn't measure them, but it seems to be at least close.

#603: Post by **clc12rock** » August 5th, 2021, 10:52 am

My pressure has been dropping the past few weeks and got down to like 3 bars. Finally opened up the machine and replaced 5 O Rings: 3 on the steam boiler and 2 on the brew boiler. This was the 2nd time I've replaced the O rings. Replacing the o rings got it back up to 7ish. Also went through the cleaning cycle with the blind basket and it got up to 8 bars. The machine used to get up to 9 bar and higher with a blind basket in it. Any idea on what else I might need to do to get the pressure back up? Are there more o rings I could replace? I have had the machine for about 4 or 5 years and I think it was about 18 months old when I bought it, so it's probably about 7 years old. I haven't replaced the gasket so I was gonna order this: https://caffewerks.com/products/ims-nan ... 98b7&_ss=r

Edit: Just saw the above Amazon link. Probably just going to order that.

Would that fit my machine? I think mine is the 920 or something, so I assume that's the right one, but just wanted to confirm before I pulled the trigger. Any advice would be much appreciated!

August 5th, 2021, 11:55 am

Yes, https://smile.amazon.com/dp/B095K94F7N? ... ct_details
This will fit your 920

8 bar at the group is just about perfect. If all the o-rings have been replaced and there are leaks in any of the lines, low pressure with the blind filter is either your OPV bleeding early or the pump is going bad. Either/both are fairly cheap and relatively easy to replace.

#605: Post by **longpvo** » August 7th, 2021, 10:44 am

luvmy40 wrote:I just received that IMS screen, SS dispersion block and Cafelat gasket.
https://smile.amazon.com/dp/B095K94F7N? ... ct_details
After a couple days, I can say it was well worth $52.43 USD
The SS block may not be necessary but does not seem to have any detrimental effects on my shots.
The Cafelat gasket should be a required upgrade. No more twisting the portafilter to 4:00. it locks up tight at 6:00
I have no opinion yet on the IMS Screen. It certainly does it's job well, whether it's quantifiably better than the stock screen, I cannot say.

I just did this upgrade on my Oracle Touch, I had fiddled with it and observed the following:

When you remove shower screen and dispersion block, you will see the other hole through which water arrives at the screen. This hole is at a slight offset at 1 o'clock from the center threaded hole.

Where that water hits the dispersion block

After I installed the upgrade kit, I noticed there was a spot of constant higher flowing stream on the IMS shower screen, I took it out all and tried to align the dispersion block so that the water outlet hole hits just in between the holes of the dispersion block, a bit tricky to align, you may need some trial and error.

It doubt it makes a big difference in taste but I'm sure it wets better than stock, and also easier to clean.

Stockhex screws will protrude below the IMS screen more, use the included screw (not flushed in like stock screw with stock shower screen anyway). Do not over tighten or you will risk develop micro cracks the 1st dispersion block in the long term.

I am not sure why they didn't design a dual water outlet like a Gaggia for even water distribution.

#606: Post by **BaristaBob** » August 7th, 2021, 11:16 am

longpvo wrote:I just did this upgrade on my Oracle Touch, I had fiddled with it and observed the following:

When you remove shower screen and dispersion block, you will see the other hole through which water arrives at the screen. This hole is at a slight offset at 1 o'clock from the center threaded hole.
image

Where that water hits the dispersion block

image

After I installed the upgrade kit, I noticed there was a spot of constant higher flowing stream on the IMS shower screen, I took it out all and tried to align the dispersion block so that the water outlet hole hits just in between the holes of the dispersion block, a bit tricky to align, you may need some trial and error.

image

It doubt it makes a big difference in taste but I'm sure it wets better than stock, and also easier to clean.

video

Stockhex screws will protrude below the IMS screen more, use the included screw (not flushed in like stock screw with stock shower screen anyway). Do not over tighten or you will risk develop micro cracks the 1st dispersion block in the long term.

I am not sure why they didn't design a dual water outlet like a Gaggia for even water distribution.

Good info Longpvo. From the video it appears the ss dispersion block actually restricted the water flow. Would you have the weighed amount of water from the two tests? That would be interesting to know.

Bob

#607: Post by **longpvo** » August 7th, 2021, 11:26 am

BaristaBob wrote:it appears the ss dispersion block actually restricted the water flow.

I highly suspect that on the stock dispersion block, this raised hump is what allows the water to spread evenly to the 10 holes on the dispersion block (on this note, I now start to feel like I may have installed SS dispersion block upside down, but it can't be, the tapered screw slots in just right the way I installed..)

BaristaBob wrote:Would you have the weighed amount of water from the two tests?

I didn't bother but now that you mentioned, I will the next time I take them out to do side by side comparison with a controlled & dialed grind.

#608: Post by **BaristaBob** » August 7th, 2021, 2:12 pm

longpvo wrote:I didn't bother but now that you mentioned, I will the next time I take them out to do side by side comparison with a controlled & dialed grind.

No need for grounds or a pf. Just place a measuring cup on a scale under the group head and push the 30 sec. button (if that's what you have preset), or what ever time you have preset...doesn't matter. This is your water debit. For our machines with no preinfusion and 30 seconds on the timer, the water debit should be anywhere from 210g to 240g/30 seconds (7-8 grams per second).

#609: Post by **topcat2001** » August 7th, 2021, 4:26 pm

Just replaced the steam tube o-ring on the boiler side as it was developing small leaks. This seems to be the most common failure as steam is existing out of this tube. Harbor freight has a viton o ring assortment from 005 to 012 and more for $10 which I used. On product page it says resistant to steam and various others but I did not see that on the actual packaging. Will report back if it develops any problems.
https://www.harborfreight.com/180-piece ... 67525.html

#610: Post by **longpvo** » August 8th, 2021, 12:17 am

BaristaBob wrote:For our machines with no preinfusion and 30 seconds on the timer, the water debit should be anywhere from 210g to 240g/30 seconds (7-8 grams per second).

SS Dispersion Block + IMS Shower Screen = 205gr in 30s (7s default pre-infusion)

SS Dispersion Block + Stock Shower Screen = 202gr in 30s (7s default pre-infusion)

Stock Dispersion Block + IMS Shower Screen = 205gr in 30s (7s default pre-infusion)

Stock Dispersion Block + Stock Shower Screen = 202gr in 30s (7s default pre-infusion)

No Dispersion Block + No Shower Screen = 205gr in 30s (7s default pre-infusion)

No Dispersion Block + No Shower Screen = 35gr in 7s default pre-infusion

The IMS shower screen is thinner and has more flex to it, if you were to over tighten the screw a bit there's a chance that the both screens will turn from convex to concave and water will flow from the rim instead of the holes.

The trick to align the dispersion block effectively is to use the front selfie camera on my iPhone, screw in, test to see how the streams are distributed, if it looks good, I'll let the machine cool down so the gasket will shrink in a bit keeping the dispersion block steady, then I'd just unscrew and putting on the shower screen.