@ davecUK. Do motors for rotary pumps have a finite/ limited life ? Mine has an 'expensive' smell when warm. I have removed it and checked that it is turning freely, no binding / rubbing, bearings are fine. It just seems the motor insulation is getting quite warm. I replaced the cap a short while ago and it appears to run fine. Any thoughts ?? Anyone /

> @"Elcarajillo"#p43034 Do motors for rotary pumps have a finite/ limited life ? Mine has an ‘expensive’ smell when warm. > > I have removed it and checked that it is turning freely, no binding / rubbing, bearings are fine. > > It just seems the motor insulation is getting quite warm. > > I replaced the cap a short while ago and it appears to run fine. The motor in a coffee machine is so lightly loaded, in general they should outlast the machine. That said motors can fail for seemingly no reason at all. At the Trieste exhibition with ACS the outboarded rotary pump for the 2 group Vostok simple didn't work, no reason, no smell, no bright flash or puff of blue. We took another motor/pump out of a different machine. If you replaced the capacitor it's important that it was exactly the right value of capacitance (voltage can be higher). If not this can cause problems and overheating of windings as the generation of the "extra phase" magnetic field becomes weak. This can happen if the capacitor value is too high, **or too low**. It's possible the previous bad capacitor overheated the windings I guess and the motor has now failed (shorted/shorting across windings). Or possibly the new capacitor is failing. Water ingress can sometimes cause problems, but these are usually with the bearings.

@"DavecUK"#p43037 Thanks for that , it was the correct cap (i did make sure ) Possibly as you said it is possible that when the other cap was failing it over stressed the motor. Will check cap and report. Thanks again.

I would like a rotary pump 😂

@"Elcarajillo"#p43040 Checked the cap 6.3 muF. +- 5%. reading 5.7 mu F. down 9% on rated. Will try a new cap first but I think the previous one has stressed the motor/ insulation.

> @"Elcarajillo"#p43110 Will try a new cap first but I think the previous one has stressed the motor/ insulation. That's quite possible….

Update, cap arrived yesterday (Sunday ) RM ? Checked the new cap = 6.3 m f actually reds same as existing 5.7 m f Fitted and ran machine , that expensive smell returned😪. Now looking for new pump motor- difficult to find correct part by number/ spec.

@"Elcarajillo"#p43699 Saved you the cost of a pump…. 😁

Rotary pump motors.

DavecUK

Elcarajillo It’s probably one of the small prosumer rotary pumps. They can be expensive unfortunately.

, but any one with the right size /flow rate will work OK.

Do you have a photo of the motor…usually it will be an RPM model.

Elcarajillo

Not sure it is the pump ,machine cut out while making coffee yesterday instant stop. Trip did not go out, checked fuse OK. Pump for sure ??. Applied voltage to pump worked fine ?? Applied the nose test to the Gicar= faint smell

Removed tank carrier to access the base= very strong smell, careful inspection showed bulge on main incoming power connection. Neutral lucar connector well cooked. Arcing in connector had been the problem.

DavecUK

Elcarajillo Saved you the cost of a pump…. 😁

Elcarajillo

@ DavecUK. PF sneeze on QM Verona, The last few days my M/ch has developed a PF sneeze after brewing.

When I lower the lever water runs from lower drain but pressure remains on gauge. If I raise the lever to just before pump cuts in water begins to run from brew head and pressure releases from gauge (slowly).

I have checked & lubed valves in brew head, checked sol/ valve and the bypass valve, all clean , clear.

Only other thought is it the combined vac valve sticking ?

Thanks

DavecUK

Elcarajillo Usually the only reason for this is, the machine unable to drain.

If the machine is indeed venting, it should be impossible for excess pressure to build up..unless at the lowest extent of the lever, some wear is causing the drain valve to close slightly again. That couples with a leaky top brew valve would develop a little pressure. However it would take time? It would also require 2 other simultaneous faults. This seems unlikely, of course not impossible.

does it do it all the time
what happens with a blind filter
make a video of the behaviour, in case I can see or hear something (include the gauge)
pressure should remain on the gauge, as it will rise as a result of cold water heating…unless the top brew valve leaks slightly

I think a video is the next step.

DavecUK

Elcarajillo PF sneeze on QM Verona, The last few days my M/ch has developed a PF sneeze after brewing.

When I lower the lever water runs from lower drain but pressure remains on gauge. If I raise the lever to just before pump cuts in water begins to run from brew head and pressure releases from gauge (slowly).

Watching the video, I see the expected behaviour….

The pressure gauge is in the sealed brew circuit = will show pressure after the shot
the group seems to vent OK?
The pressure drops from the brew gauge when you lift the lever to just before a shot = top brew valve opens (just before pump activation)…and pressure drops away, as it should.

So every thing seems normal except for the portafilter sneeze…does it do it all the time, or intermittently.

all the time could be a leaky top brew valve, causing a little pressure…If you wait you should see the pressure gauge drop after a shot.
Sometimes, could mean an intermittently leaky brew valve

Do you ever hear the pump cavitate slightly and no water appears from the open group for a few seconds after the machine has been idle a long while, or does the thermosyphon ever go cool?

Elcarajillo

DavecUK ![](https://)

DavecUK

Elcarajillo The link appears to be missing?

Elcarajillo

video

DavecUK

Elcarajillo I can’t see a link/video?

Elcarajillo

I am still steam driven🤣

Elcarajillo

DavecUK Thanks for the notes.
I did check the brew valve but it is fairly new (green) seal, I also carefully checked the raised seat area for any nicks or damage= nothing. No pressure drop after a wait.
Not heard any pump cavitation and thermosyphon OK. Will continue to observe.
On the vid MediumRoastSteam linked, as he says ,it does the same less a sneeze ?

MediumRoastSteam

It doesn’t seem normal to me for the gauge to not move back to near zero after venting. What I’m seeing was definitely not the case when I had my Pro-700.

Edit: so I had to do my homework… And a quick video on the Quickmill Vetrano shows exactly as per video above and as per Dave’s comment.

Maybe a “Quickmill” thing?

On the Profitec, it moves towards zero… Unlike the QM: gauge on the right, around 3 mim mark.