Quickmill Andreja - Where to start with brew pressure problems?

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
acodring

#1: Post by acodring »

Hello,

A couple years ago this forum helped me resolve an annoying problem where P-Stats would fail prematurely in my 2004 Quick Mill Andreja. Now I'm hoping you can help me again, but this time I'm not really sure how much of a problem I have, nor where to start to resolve it.

I bought the Andreja used about 7-8 years ago. It was my first espresso machine and it has taught me many lessons but I still feel like a newbie. We mostly just drink milky drinks so nasty pulls are easily hidden and I'm not a skilled taster anyway.

Based on what I've read in various threads I don't think pressures are correct. For quite a while I've assumed that my grinder (Vario w/ ceramics) wasn't fine enough but now I'm suspicious that it's more than that. I'm not sure if I have a problem with the pump, valves around the pump, or with the E61 valves and cam. I did my last group rebuild with new valves and springs in 2016. I didn't notice it then, but something could easily have been wrong since then.

Rather than clumsily try to explain my guesses at what the problem is I thought I'd just video the machine in operation. If you've got a moment to watch and have any hints for where to start my troubleshooting I'd really appreciate it.

Here's a video with a blind basket (43s):
And here's a video of a 15g shot (1m7s):
Thanks!
Andrew

Jeff
Team HB

#2: Post by Jeff »

I had an Anita and 12 seconds to pressurize a blind basket seems like a lot. I seem to recall 5-7 seconds.

The pumps on these can get weak before they fail. At 16 years, if it hasn't been replaced, that would be my guess.

There are several EX5-series Ulka pumps. They all have the same pressure and flow specs. They differ by duty cycle:

EAX5 -- 1 min on, 1.5 min off
EX5 -- 1 min on, 1 min off
EFX5 -- 2 min on, 1 min off

The EX5 is often available on Amazon for ~$30. The EFX5 is a little harder to find and usually runs around US$50. I believe iDrinkCoffee in Canada has the EFX5 at CAD $65. Last I checked, they ship free to the US for most "unrestricted" items (certain lines are geography-restricted, such as Breville).

The pump swap is pretty straightforward with a couple small wrenches and usually a Philips screwdriver. Make sure you re-seat the "Klixon" over-temperature switch in the new housing. Priming an Ulka can be a challenge. Several threads around on that, involving squeeze bottles, turkey basters, and all kinds of things to try to push water through the new pump. When priming, don't run too long as there isn't any fluid to cool the pump. Maybe 10 seconds, then let it sit for a bit before trying again.

It's hard for me to say that the EFX5 is $20 better than the EX5 for typical E61 boxes and typical shot lengths. If one of the professionals weighs in with a different opinion, they have probably hundreds of times the experience in replacing these pumps that I do.

acodring (original poster)

#3: Post by acodring (original poster) »

Thanks Jeff.

I replaced the pump and OPV in 2016. Pump hadn't completely failed, but I didn't know how old it was.

When I searched email to figure out when I replaced it I saw that I was concerned about low pressures (6-8bar) while pulling shots then, right after installing the new pump. A service tech recommended a new valve seat which I got and installed. Then I got distracted by the pstat problem so I'm not sure whether it helped.

If suspicion is on the pump I think my next step is to check flow rates, right?

I'm also confused by the way it doesn't release group pressure until I jiggle the lever up a little bit. That seems like a valve or cam wear problem. Could it just be that I'm dealing with multiple problems at the same time?

tinman143
Supporter ♡

#4: Post by tinman143 »

If it's not the pump perhaps it's scale? How's your water situation?

acodring (original poster)

#5: Post by acodring (original poster) »

tinman143 wrote:If it's not the pump perhaps it's scale? How's your water situation?
The pump is not off the prime suspects list but as I've read more related threads here I've realized it could be several other things.

One thing I've learned is that water here in Ottawa is quite soft. From https://ottawa.ca/en/living-ottawa/drin ... -questions:
Ottawa's central drinking water supply is about 30 mg/L (ppm) of total hardness which is considered very soft. This is equivalent to 2.5 grains per gallon of hardness.
Before I found that info I was descaling every few months. Now I descale once a year.

JRising

#6: Post by JRising »

#1, I see you point at the gauge showing 10Bar after you've completed the "Brew Section" of the backflush and the grain valve is open. What you've got is the Brew Valve closing before the control lever allows the pump to stop pumping. As you can see, the brew lever sits in a chromed cam (with that bid flat-head screw holding it to the shaft that turns the other cam inside the brewhead). Raising the lever causes that chromed cam to push the brew button on the face of the machine. There is a "deadband" of play in that button, it doesn't close (activate the pump) until the cam has pushed it over-center, and doesn't open (deactivate the pump) until travelling over center in the other direction.
You can open the mushroom (the larger of the 2 nuts on top of the E61 head) and inspect your brew valve. If the cam-riding end is badly worn, then the cam may not be raising/opening it far enough while also aloowing it to close early. If the rubber valveface in that valve is all swollen and extruding from its seat, it may be blocking flow (closing) too early.
If the valve looks good, then it probably is, and the issue may be with the length of the brew button. You can loosen the nut on the front of that button 2 full turns, then tighten the nut behind the wall to re-secure the switch to effectively move the switch back a step so that the chromed cam engages it a little later and releases it a little sooner.

#2, It does take a while to ramp up to pressure. Check your return hose for flow when running the machine with no portafilter. The OPV shouldn't start relieving until the brew-circuit exceeds 8 bar. If your OPV is dribbling away some of the flow at less than 7 bar, the problem is in the OPV. Clean/Descale/Replace/Rebuild it if possible.

Nate42

#7: Post by Nate42 »

Just a few things to add - 4-5 years is about the expected lifetime of those pumps, so even though you replaced in 2016 its entirely possible it is at least weakening at this point. It might be able to achieve adequate pressure but at reduced flow. Look at the return line from the OPV that returns water to the tank. When using a blind portafilter, 100% of the flow will be returned to the tank. If there is no flow, or flow that looks too low for a reasonable shot of espresso, your pump is getting tired. This isn't to say other causes aren't possible, but my experience with these pumps is that they are frequently the problem.

Regarding desclaing, descaling when you don't need to will do more harm than good. Given you have soft water I would periodically flush the boiler with distilled water and never descale the boiler. I would inspect the mushroom periodically to determine when descaling the HX is needed.

acodring (original poster)

#8: Post by acodring (original poster) »

Holy smokes. Great feedback. Thank you all very much!
JRising wrote:#1 ... What you've got is the Brew Valve closing before the control lever allows the pump to stop pumping...
That makes tons of sense. I'll get some tools out tonight and check these.
JRising wrote: #2 ...Check your return hose for flow when running the machine with no portafilter. The OPV shouldn't start relieving until the brew-circuit exceeds 8 bar. If your OPV is dribbling away some of the flow at less than 7 bar, the problem is in the OPV. Clean/Descale/Replace/Rebuild it if possible.
Here's a video of the outflow with no portafilter in place. If I've understood you correctly, I've got an OPV problem.
Nate42 wrote: When using a blind portafilter, 100% of the flow will be returned to the tank. If there is no flow, or flow that looks too low for a reasonable shot of espresso, your pump is getting tired. This isn't to say other causes aren't possible, but my experience with these pumps is that they are frequently the problem.
Here's a video of the outflow with a blind portafilter:
That flow looks reasonable to me. I'd guess my pump is still OK. Should it be stronger?
Nate42 wrote: Regarding descaling, descaling when you don't need to will do more harm than good. Given you have soft water I would periodically flush the boiler with distilled water and never descale the boiler. I would inspect the mushroom periodically to determine when descaling the HX is needed.
Thanks. This makes sense. I'll modify my maintenance accordingly.

When you say 'flush with distilled' does that mean:
  • "fill the boiler with distilled then empty and immediately refill with tap water"
or
  • "fill the boiler with distilled and leave it, with gradual replacement with tap water over time"

Nate42

#9: Post by Nate42 »

I would say that your OPV outflow with blind portafilter looks reasonable. If you want to get picky you could weigh the output over a 30 second period and make sure it is greater than your typical shot weight. But judging from the video, I would say that the pump is probably fine for now.

Your OPV outflow with no portafilter looks a little high. So I would agree that your OPV is suspect. You might start by just disassembling it and cleaning it. You can get replacement components from Chris coffee. The valve seat is a common failure point and is meant to be replaced periodically. https://www.chriscoffee.com/products/ex ... ement-seat

Regarding my statements on filling boiler with distilled water, I meant to fill the boiler and leave it, there is no need to drain the distilled water afterwards. In practice what I typically do is purge a little water using the hot water valve periodically and allow it to be replaced with distilled. I don't typically go to the trouble to fully drain the boiler.

If you are going to completely fill with distilled, it might be worthwhile to add a teensy pinch of baking soda to make sure it is alkaline. Probably not strictly necessary but a nice bit of insurance.

nahau

#10: Post by nahau »

It's the pump. Take a trip to the hardware store and purchase a 5mm x 2mm or 5/16" x 3/16" plumbing o-ring. Take the pump apart and replace the small o-ring for the piston. Pulling with a blind basket only tells you what pressure the OPV will release at. Pulling with a blind basket is how you adjust the OPV, correct? Since the brew circuit is "closed" when pulling with a blind basket, the pump will eventually reach the OPV setting even if it's a bit weak, thus you'll see the correct reading on the gauge. However, when you pull a shot, the brew circuit pressure is determined by the coffee puck and the pump has to be able to maintain that pressure as it's basically an "open" circuit of flow. If the piston o-ring cannot seal around the piston, then the pump can't maintain the pressure, so you see low pressure on the gauge.

I've repaired a lot of pumps, and continually do so over the years. It's almost always the piston o-ring that gives the symptoms you're seeing... good with blind basket, bad while pulling a shot. Attempting a repair is a cheaper troubleshooting route than just replacing the pump right away.

Not saying it couldn't be anything else, but if you suspect the pump, try the o-ring first. Be carefull not to lose any small pieces... especially the little white ball. Also, clean the scale off the parts of the pump. The white cap (lower right in the photo) unscrews from the brass fitting. It's used to capture a spring and one-way valve. Remove the white cap so you can clean the valve and valve seat of scale. If you've never overhauled a pump before, take photos for reference at every step.