I own an Izzo Duetto MK4. Bought back in 2014. I have serviced it a few times and has been a great learning tool. Recently I noticed that the coffee seemed weak and a cursory look at the brew pressure gauge identified a low pressure of around 4 bar. I also noticed the backflush was weak. So I stripped the e61 down and lubricated ( molykote). the backflush problem was instantly cured but the pressure remained low. I decided to adjust the brew pressure screw and after reaching the maximum adjustment I now have 9 or so bar pressure but more importantly great coffee again. Although it would appear there is no problem now I suspect myself the OPV is playing up as why do I need to adjust to maximum the brew pressure? Compensating for a leaky OPV maybe? I have phoned BB and spoke to a technician who said the OPV has nothing to do with it. if the pressure is low then the pump is at fault. I am sceptical. My question is: 1. Can a faulty OPV cause low pressure? 2. If that is the case where is the water going to? as there is none coming out of the little tube by the tray. The machine is plumbed in. 3. How difficult is it to change an OPV on the izzo? 4. Where can I find the part if I need to? 5. Is it maybe the pump? 6. What symptom's should I look for? I should point out that about a year ago I cleaned the OPV as water was constantly coming out of the little tube by the front tray. That rectified the fault at the time. Don't get me wrong the coffee extraction is perfect but I feel with the brew adjustment on maximum is not right.

> @"coffeealex"#p24880 > > 1 Can a faulty OPV cause low pressure? > 2 If that is the case where is the water going to? as there is none coming out of the little tube by the tray. The machine is plumbed in. > 3\. How difficult is it to change an OPV on the izzo? > 4\. Where can I find the part if I need to? > 5\. Is it maybe the pump? > 6\. What symptom’s should I look for? 1. It can. 2. It would be being returned to the tank (in quantity) via the tube from the Expansion valve (OPV). **Have a look and see if this is happening when pulling a shot against a blind filter. If it's not, discount the expansion valve.** 3. It's easy 4. Bella Barista or most internet espresso machine spares retailer, the part is quite generic. Remember this part is only to vent excess hydraulic water pressure due to water expansion on heating. It has no part in brew pressure regulation as in a vibration pump machine. **It's unlikely to be the cause of your problems (as you have described them)** 5. Yes, most likely The things to watch for are each symptoms cause stated in order of probability: * the brew pressure needle showing back and forth variations, e.g. from 5 bar to 9 bar or 7 bar to 9 bar etc.. (balanced bypass playing up, seizing pump, failing capacitor) * funny noises (pump seizing up, balanced bypass) * the motor sometimes failing to start (capacitor) * Pump struggles to make pressure (damaged/worn vanes, motor capacitor) Make a good quality video (with sound) of a shot pulled against a blind filter, upload to YouTube and link to it here. **Show the brew pressure gauge**

https://youtu.be/7CkNkNFf81E Thank you for your answer. I have uploaded the video. As previously mentioned it does reach pressure ok but the brew pressure setting is at maximum. The guy at BB said at the time that in his opinion the valve was stuck and that by turning the screwhead i freed it and so the pressure went up and is now ok. Does not explain why I needed to turn it so much to get it back up again. Excuse my ignorance in this.

@"coffeealex"#p25028 was the motor/pump always that noisy? Can you show a photo of your pump and what you adjusted. Look at the weep hole in the pump connection to the motor, has water been coming out?

[upl-image-preview url=https://i.imgur.com/KbPs4yL.jpeg] [upl-image-preview url=https://i.imgur.com/PJYWifv.jpeg] [upl-image-preview url=https://i.imgur.com/a5Gh15j.jpeg] I have posted a few pics. The screwhead (acorn shape) is shape is what I adjusted clockwise. I think the weep hole is that pipe and it looks dry. The noise has changed. It was more like a wow wow sound before and the case made a vibration sound. Now the vibration from the case has gone and thinking about it it does seem a bit louder.

[URL=https://i.imgur.com/t6mm5Qc.jpg][IMG]https://i.imgur.com/t6mm5Qc.jpg[/IMG][/URL] Another pic from top. Also had a look at water tank to see if water is going back to it and it is bone dry. The green stuff on top of the brew boiler I am assuming is a previous leak to maybe when I replaced the temperature probe as although it looks green it is dry .

Well a few things…that tube is a waste of time….it does nothing to protect the motor bearings. I wrote this article after the MK1 Duetto was launched. You may well need to inspect yours…torch and spanner required. http://coffeetime.wikidot.com/duetto-pump-checks-and-home-made-leake-detector you should take a video with the top off and the camera on the pump…shot against a blind filter…oh you can leave the pump running for more than 3 seconds after the pressure maxes. The machine needs a serious clean in side and the bottom below all the components and boilers. A clean machine allows you to see problems faster then if it's still leaking, fix the leaks, esp on top of the brew boiler. * What water are you running? * Have you owned it from new, or did you buy it used? * What does your servicing entail, what have you replaced? * Take a photo from the top at a greater distance, we might spot other problems for you.

[upl-image-preview url=https://i.imgur.com/5V8Y2Qa.jpeg] [upl-image-preview url=https://i.imgur.com/FIszBHA.jpeg] [upl-image-preview url=https://i.imgur.com/fwRBcn5.jpeg] [upl-image-preview url=https://i.imgur.com/W6P69yF.jpeg] Listened to your great advice and started to clean it. * The water is coming through a bestmax premium filter * Yes i have owned from new. Purchased in 2014 from BB * replaced temp probe on brew boiler. Opened up OPV and cleaned after it was constantly losing water from tube into drip tray. Problem solved after cleaning inside of OPV. Have cleaned and lubricated cam on brew lever about 9 times. cleaned filter under brewhead and replaced later. Changed gasket seal under brewhead. Recently stripped all of e61 , top( mushroom) and bottom and cleaned as water was not backflushing with any force. Now it does after clean. https://youtube.com/shorts/KXhYhaYNhCM?feature=share

Looks much better, now you can see where leaks are coming from. I'd double check the hardness of your water. Pump or motor sounds noisy, split pump from motor and check for leaking.

Thank you Davec. I have never removed a pump before so can I check the procedure please. * Make sure the machine is off and cold * loosen 2 nuts: 13mm and 17mm * loosen screw from collar underneath pump and lift body of pump upwards * check underneath pump and in well for signs of water leakage. Is the above right? Thanks I have found this link which seems to explain which nuts to loosen :https://clivecoffee.zendesk.com/hc/en-us/articles/360001221713-Izzo-Duetto-Pump-Replacement The more I think about it the more I don't think the pump was ever this noisy, so I am starting to think along reason 4 you mentioned earlier > @"DavecUK"#p24944 Pump struggles to make pressure (damaged/worn vanes, motor capacitor) This is a great learning curve. I really appreciate you passing your knowledge on.

[upl-image-preview url=https://i.imgur.com/JPoxGsp.jpeg] [upl-image-preview url=https://i.imgur.com/khu2DiU.jpeg] [upl-image-preview url=https://i.imgur.com/LCakQaV.jpeg] [upl-image-preview url=https://i.imgur.com/E15QTbt.jpeg] Oh well. I think its game over. I loosened off the pump and I think water has been going into the motor. Does that mean a new motor and pump would be needed? The odd thing is it works still ok? Is the loud noise coming from the motor rather than the pump? I am no expert and far from the inspirational knowledge of Dave C and others, but surely is that not a stupid design to put a pump over a motor that way or am I way too ignorant to see the merit?

Alex Izzo Duetto Mk4 low brew pressure

coffeealex

DavecUK Ordered a new motor and pump yesterday from BB. You are totally right it would be folly to risk that they have none in stock as the price of the motor is very reasonable. I have also an agreement that if in the worst case scenario there is a compatibility problem they will take it back and refund. Therefore its a low risk move.

DavecUK

coffeealex I am also fairly sure it’s exactly the same motor as in your machine as I believe it has been in stock a very long time.

P.S. Do NOT spray WD shite or anything else into it’s bearings thinking the grease in them has dried up. It won’t have, and you will ruin the long term life of the motor. In fact the best thing you can do with the WD40 is give it to someone you don’t like.

CoyoteOldMan

DavecUK And suggest they spray it as an ‘extraction aid’ on their freshly tamped grounds.

coffeealex

Arrived quicker than I thought

DavecUK

coffeealex make sure the spring is in the inlet port… bit with cotton wool in it.

coffeealex

DavecUK

Would explain why there is cotton wool stuck in only one port. Is the spring that bit that you can see?

DavecUK

coffeealex Can’t see a spring. Perhaps they stopped using them? Part number 25. It acts as the bypass retainer.

https://www.fluidotech.it/site/assets/files/1300/co_50-200_rotary_vane_pump_spare_parts.pdf

How about a few more photos so I can see if it’s a Procon or FOT and the number. Who did you get the pump from.

coffeealex

DavecUK

Maybe, but then why put cotton wool in there. Might be worth me ringing BB to check if spec has changed. What is the spring supposed to do?

coffeealex

DavecUK For the little I know and looking at the Fluid O Tech website most have a spring although some like the 50-100 don’t. So as you say unless the site is not up to date and the spec has changed the 50- 200 should have a spring and one thing is for sure you have seen a lot more pumps than I have, so definitely guided by what you say. Thank you.

DavecUK

coffeealex

The balanced bypass valves opens under pressure to allow water to flow from outlet to inlet. The spring prevents the valve entering the inlet chamber.

It would be super great if you put up the photos I asked for so I’m not working blind.

P.S. the foam or in your case cotton wool stops crap getting into the pump, as per the installation manual and is removed just before connection.

coffeealex

DavecUK Sorry Dave. Just saw the bit about the photos. My bad. will do that now

DavecUK

coffeealex Remember, your old pump should have one in the inlet, if it’s original.

coffeealex

DavecUK Suppose in the worst case scenario I could just take the one out of the old one. Did get changed once after 2 years by BB, so cant be sure until I get it out. Did the pics help? I’ve got an SKU number of LFS1330005 if its any help. Thanks

coffeealex

Got the pump from Bella Barista

DavecUK

coffeealex For the little I know and looking at the Fluid O Tech website most have a spring although some like the 50-100 don’t.

I’m not familiar with the 50-100, unless you mean the 500-1000 which doesn’t have a bypass, so of course won’t have a spring. If you can link me to the 50-100, I will have a look.

coffeealex

DavecUK You are quite right. I missed the zero at the end. Dave, you are a walking encyclopaedia! If I could get you patented I would.

DavecUK

When I made my second post on this thread https://coffeetime.freeflarum.com/d/1026-alex-izzo-duetto-mk4-low-brew-pressure/4 I was pretty certain your pump and motor were both shot.

Hopefully once you get your old pump out you will see what work remains…the mountings should fit directly on the new Motor. If they were aware of the need for the spring your existing pump will have one you can use..

coffeealex

DavecUK

Dave just need some advice please. Got the old pump out. Took quite a bit of effort taking the old tails out but got there.

Just a little advice on the following:

Pic of old and new pump. They seem spec wise the same. Am I right?
I have put ptfe tape before I screw new tails into new pump. Is that right?
There was an old spring in the old pump but tried to put it in the new but seems to protrude (see pic) so I think they have modified it so maybe does not need it. Asked BB they said they come that way now. So I will just leave it out? Ignore the pic with spring in wrong place
The electrical connections (see pic). Does the copper bit just pull free. If so what is that type of connector called so I can look for some to fit the bare wire in new
The mounts on the bottom of the pump are like those bobbin mounts you mentioned. So was going to unscrew the old to fit the new as seem ok or would you advise buying new as working out the size of thread to tap might be easier.
As I cannot fit the pump for the time been was going to put the new tails into the new and put that one on on for the time being.
( bottom of motor showing three threaded areas absent on new motor that I will endeavour to get tapped, to match the old motor)

coffeealex

DavecUK

Managed also to get some clarification direct from fluidotech re spring. As you suspected they might not use them re new modification. Attached copy of email received

DavecUK

coffeealex Sounds like you’re on the right track. Izzo themselves would have drilled and tapped the threads in the old pump.

Good to hear that FOT modified the pump to no longer need a spring, so really all that remains is for you to drill and tap that motor then screw it back in, I’d use the existing mounts unless cracked or broken.

CoyoteOldMan

Not Dave, but my 2 cents all the same:

No idea if the new and old pump are the same; they may share the same casing blank, but the vanes be different. Is the number on the old pump 4495W? If so, all is good.

PTFE on the tails does not hurt, though they are unlikely to need to come off again. However, before you screw them in, a photo of the seat in the old pump where the spring was, would be good. I suspect that the spring may still be required (and needs to be compressed by the tail pipe).
The brass connectors should just pull free, but some may need pushing-in in the middle before they release; the picture angle does not show if they have a safety tongue. They are spade connectors, probably 6.3 mm (¼″), can easily find them in automotive stores (Halfords). While you are at it, I’d give a couple of turns of insulating tape on the bare end on the blue wire, or even better fit insulating caps before you crimp the connectors to the new cable. If you can’t find insulating caps, leave the ground wire (yellow/green) without it, and fit the old two to the other two wires.
Tap size for the motor mounts will be metric. Probably M6, eyeballing it, but if you measure the diameter of the stud on one of them you can confirm. It’s going to be the nearest number in whole mm (i.e. a diameter of 5.89 mm = M6)
I’d wait to fit the new pump until the issue of the spring being needed or not is resolved. (Mounting the new pump on the old motor is not ideal, if the shaft of the old motor moves in ways that it shouldn’t, either…)
Also, check that the rotation of the new and old motor is the same. Power and RPM are good, but they are a different type number - is it just because of the mounting, or is the rotation opposite? Unfortunately all the photos you have taken don’t have enough context for me to figure it out. Put the two motors next to each other, “pump” side up, and look at the labels. Do the “ROT. <<<<<” arrows point the same way?

Bit of belt-and-braces, but I’d rather make sure than throw away £150 in parts…

coffeealex

CoyoteOldMan

Thank you. Not that I know much more, I think although the pumps share a different number they look identical to each other to look at and are the only ones that shape that fluidotec do. So I am assuming should be ok ( hopefully). It was listed as an Izzo pump on the bella barista website.

I think re spring should be ok as it seems this one does not need it ( which probably explains the different numbers as these are slightly different in the way the bypass works)

coffeealex

CoyoteOldMan Put the two motors next to each other, “pump” side up, and look at the labels. Do the “ROT. <<<<<” arrows point the same way?

Think they look the same to me except the mounting on the right which i could reuse the bracket of the old, I think

I will put the tails on the old pump and reinstall old one until I have everything ready. At least the picture is clearer and should come off easier as I think tails were a little seized. I thought I needed to get some spinach down me to prize them off!

CoyoteOldMan

coffeealex In which case, ignore my request of a photo of the seat of the spring in the old pump. Clearly not needed.

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