ACS Vesuvius #0018 - brew pressure not reaching target.

yojabbajabba

Hello fellow coffee-natics!

I have an ACS Vesuvius that is struggling to meet the brew pressure targets set in the profile.

I read this post and made me wonder if my gear pump is also the owner of some original, dodgy magnets.

Serial number of device is #0018, according to the original distributor Talk Coffee P/L in Melbourne, VIC, Australia (original serial label wasn’t there when I purchased it).

The machine is stock except for the anti-vacuum valve (the original Fluid-O-Tech one cracked at the plastic housing, and was replaced with this brass one from CoffeeParts.com.au in September 2024). Have I cooked the target brew pressures because of this part replacement?

Further, once every few weeks the machine will trigger the gear pump (click sound) but the pump does not run at all. A hard turn-off of power (at the 240v power point) for at least 30 seconds will re-trigger the pump and will be back in action (video to-be-uploaded once I have one).

Link to videos showing target pressure not being achieved. : https://www.youtube.com/playlist?list=PL3gbyR2UDQpIKFe4b-sKVPi47XbttY1AJ

Video 1: Profile 5 set at 11.0 BAR continuously against a solid blank portafilter basket, pressure floating at 9.0 BAR.

Video 2: Profile 5 set at 11.0 BAR continuously against a Weber Spring Clean device, pressure going up to 6.0 bar.

Video 3: Profile 2 set at 2.0 BAR for first 7 seconds, 9.0 BAR for the rest, not achieving peak pressure post pre-infusion. (Coffee - house blend espresso, 19.5g/4Xg out)

Video 4: Video 3: Profile 2 set at 2.0 BAR for first 7 seconds, 9.0 BAR for the rest, not achieving peak pressure post pre-infusion. (Coffee - house blend DECAF espresso, 19.5g/4Xg out)

Video 5: Machine Settings of ACS Vesuvius at time of recording.

What should I do next to address the brew pressure issue?

Thanks in advance!

Aaron J

Melbourne, Australia.

DavecUK

yojabbajabba Have I cooked the target brew pressures because of this part replacement?

No, have you owned the machine from new??

yojabbajabba Further, once every few weeks the machine will trigger the gear pump (click sound) but the pump does not run at all. A hard turn-off of power (at the 240v power point) for at least 30 seconds will re-trigger the pump and will be back in action (video to-be-uploaded once I have one).

This is a little odd, points to an issue other than pump magnets.

yojabbajabba I read this post and made me wonder if my gear pump is also the owner of some original, dodgy magnets.

If yours had the fluid-o-tech vacuum breaker (the black memory metal one, la Marzocco use the same one), then it is not serial number 18, but much later than that (see text in bold) and way outside the pump magnet issue which was almost a decade ago. They were badly potted magnets and O2 would get to the cobalt samarium, corroding and weakening them over time. Those will have worked through the system long ago. Unless of course the valve was replaced by someone years ago, did your valve look like this?

I watched the video, doesn’t seem to be anything wrong with the magnets (when there is, they progressively weaken over time and eventually can’t even make 5 bar. In addition you can hear, the motor throttling back, something done by the PID circuit. You could possibly tweak the pump PID settings….to make it get closer to the set point. try reducing kD from 90 to 80, see if that creates an improvement.

If this doesn’t help, it could be the main board, which might well tally with the pump sometimes not running at all, or it could be something else.

P.S. I should add that those main boards have been pretty bulletproof.

yojabbajabba

Thank you very much @DavecUK for your thorough response to my query.

Here are some responses and updates that have occurred since this last interaction:

The case of the dubious serial number. Well, it turns out I was looking in the wrong place for the serial number label; behind the water tank is the serial number of the machine, and it is indeed D00018!

I have not owned this machine from new; I am the second owner since originally sold by Talk Coffee P/L.
The vacuum breaker that was replaced is indeed the one that is shown above (thanks for the picture reference Dave!) - black plastic cap, SMA memory-metal valve actuation that would allow steam to pass thru into the drip tray for part of the heating process. I replaced it with one of these instead. It does work, but it’s also the first and only part I’ve replaced on the inside of the Vesuvius. Q: is the anti-vacuum valve I installed sufficient, or is there a more suitable part I could order in its place as an OEM/best practice solution?
Thank you for the tip to tweak the PID values for the brew boiler, and in general helping me to face the music that I should invest some time and cognitive load in understanding the whole concept of PIDs. Modifying the PID values have not made a significant improvement to the brewing of espresso in regards to pressure, never reaching the target 9.0bar, instead keeping to around 7bar at a maximum, the same as the previous videos. Is it possible that the magnets are weak-enough as to impede the pump motor achieving an output that is equivalent to 9bar at the group, yet strong enough that it can successfully modulate pressure up to 7.6bar (such as the target pre infusion pressure of 2.0 bar, and where it is floating at that maximum pressure of 7.5-7.6 bar)?
I reached out to Maria and got a quote for the replacement magnets for the FG304 FOT pump; 35 Euros + 60 Euros shipping to Melbourne, Australia. Are there any distributors of these magnets in Australia?

DavecUK

yojabbajabba It looks like yours is an early one, so it’s possible it’s the pump magnet…cheapest thing to try first. Any supplier of fluid O tech parts should be able to get one for you. Or tell you where you can obtain one.

http://www.processpumps.com.au/prod_fluidotek_gear.html

https://pumpsolutions.com.au/pump-spare-parts/

yojabbajabba

Hello DaveC, Maria and everyone else who finds this thread.

Here is an update on my beloved ACS Vesuvius saga:

I received a quote from PumpSolutions.com.au for a replacement magnet; they said that the manufacturer was not supplying magnets by themselves, so quoted me for the pump instead. $1500 AUD was the quotation cost!
I proceeded to purchase the magnet via ACS directly (thank you kindly Maria for processing it so swiftly! It was ordered on Thursday and was sent express from Italy to Australia by Monday morning. I followed the instruction video on how to replace the magnet, and about an hour later the pump was reassembled and put back on the bench to test.

Here is the final result: Profile was set to 3.0 BAR for 5 seconds, then 9.0 BAR for the rest. Coffee: Colombian Decaffeinated (EA process), roast + 10 days. Grinder: Baratza 270Wi with Type A burr-set. WDT + flat tamp…

Thank you DaveC, Maria and the many others who were super helpful in their posts on CoffeeTime forum. It’s good to be back with such a stellar machine!

DavecUK

yojabbajabba I received a quote from PumpSolutions.com.au for a replacement magnet; they said that the manufacturer was not supplying magnets by themselves, so quoted me for the pump instead. $1500 AUD was the quotation cost!

That’s appalling, especially when the problem is so easily solved, seems like that company was happy to create fully working e-waste. One wonders how many of those gear pumps in different makes of machines were needlessly dumped all for a cheap spare part.

It’s a shame that it had to be shipped all the way from factory, but I’m pleased it’s now sorted. I may have a word with FOT when I am at host this October.

https://www.depcopump.com/datasheets/Fluid-o-Tech/MG_Series_MG200_Parts_List.pdf

https://www.depcopump.com/datasheets/Fluid-o-Tech/MG_Series_MG200.0_Parts_List.pdf

Amazing how there is a parts listing and part numbers!

John_Yossarian

yojabbajabba Glad you have sorted out the pump. Enjoy the coffee!

yojabbajabba

https://www.depcopump.com/datasheets/Fluid-o-Tech/MG_Series_MG200.0_Parts_List.pdf

Amazing how there is a parts listing and part numbers!

DavecUK I might follow up with an email to see if there was a misunderstanding and whether they’d quote again knowing this info.

DavecUK

yojabbajabba I’d be tempted to, now of course they are not going to do a special order for a magnet, but to simply ass 2 or 3 magnets to their next order would cost them very little. It would then prevent e-waste of an expensive and fully serviceable product.