Time to replace pump?

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
pig140
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#1: Post by pig140 »

So I got a little problem that is slowly getting worse. When we let our VBM JR sit idle for awhile, the pump is slow to kick on. I flip the lever, water starts to trickle, and the pump doesn't activate for 10-15 seconds. After that, anytime you flip the switch, it acts normal. Time for a new pump?

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nahau

#2: Post by nahau »

Depending on how your machine is wired, it might just be a bad brew switch. The brew switch might be wired directly to the pump and if that's the case, as soon as you lift the lever, the pump should turn on.

You might try measuring across the switch leads with an ohmmeter to verify if it reads a short when in the ON position (lever fully up) and open when it's in the OFF position (lever fully down). Please disconnect power from the machine before you go testing inside.

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Giampiero

#3: Post by Giampiero »

As nahau said, it could be or the brew switch, or ( depend how is wired) the control board, or maybe even the low water micro switch.
If the culprit is the low water micro switch you should probably see the heating element light goes off...if is on during the brewing test.
I mentioned even the control board because in some model it is between the brew switch and the pump.

Nunas
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#4: Post by Nunas »

Put a meter on your pump and look to see when it receives voltage. If it receives voltage when you raise the lever, but the pump only develops pressure after a delay, then it's the pump. If the pump does not receive voltage until later, then it's a control issue. However, it may be both. While it's normal for an e61 to trickle when the lever is raised, what you're getting seems more than a normal amount to me. I only got a few drops on my Magister e61 HX, with no pump running and the lever raised above the mid position, likewise on my Synchronika. Unless your machine has a bunch of tubing higher than the group, which is unlikely, the trickle of water you're getting is likely the head pressure of your reservoir. Since the reservoir water has to run through the pump, I wonder if the pump seals are getting tired. You can see if it's head pressure from the reservoir by dumping half the water out and retesting, with the reservoir's head lower than the e61, nothing much should come out.

pig140 (original poster)
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#5: Post by pig140 (original poster) »

Thanks for the replies guys. I did a lot of testing on it last year when I had to send the gicar to be fixed so I'm very comfortable working on the insides. The low water microswitch and indicator light are functioning as they should.

After the first long pause, once it finally activates, every subsequent flip of the lever activates the pump immediately as it should - until the machine again sits idle for a few hours. Another clue is that I occasionally hear the machine top off during the day and the pump has the same hesitation if no one has run a shot in awhile. I hear the click but there's quite a few seconds before the pump activates.

Also when I'm dialing in a new bag and the grind is fine enough to choke the machine, the pump squeals like mad. Same when we backflush it. But it's been doing that for a couple years.

I'll check the switch, just in case. That would a much quicker and cheaper repair. I'll check pump voltage and head pressure also.

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slipchuck

#6: Post by slipchuck » replying to pig140 »

If the pump comes on during the day for no reason then you might have a tiny/small leak somewhere



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pig140 (original poster)
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#7: Post by pig140 (original poster) »

Ok, so I checked continuity across the brew switch and found no problems. I also checked the voltage at the pump as the brew lever is being raised. I'm getting 120v at the pump as soon as the lever is raised.

Here's the weird part... now that I've got it open, I can't seem to replicate the problem. It seems that now that I've opened up the cover and manipulated the pump around to access the terminals, it's working better. It's only hesitated a couple times, and then maybe 2 seconds. I unbolted the mounts and really worked the pump around to get access. I also loosened and tightened a tubing joint and disconnected/reconnected the brew switch terminals (the VBM JR internals are really packed in tight).

So the pump gets power, but at first took awhile to build pressure - slowly getting worse and worse over months. Now that I've moved the pump around among other things, its seems to be back to normal (I don't expect that to last). Maybe some trash in the pump or a bad seal?

I ordered a pump anyway, so we'll see.

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pig140 (original poster)
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#8: Post by pig140 (original poster) »

It turned out to be the pump. New pump installed and I can't believe how different the machine is running. It's SO much better. It's quieter, it doesn't squeal if the grind is too fine, and the pump activates immediately upon raising the lever. It doesn't even rattle the cups on top. It's running so smooth it feels like a new machine. I guess we just got used to the old weak pump. This was past due.