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Fluid-o-Tech Vibe Pump Problems

paranomiaparanomia
edited January 1970 in Projects & Rebuilds
Hi All,

I'm trying to repair a BZ99 which stopped pumping water - all the noise, no water.  It has the older Fluid-o-Tech 70W vibe pump.  After completely pulling the pump (and OPV) apart, cleaning & descaling - no joy.  Replaced the diode - no joy.  Purchased a new pump - no joy.  :tearhair:

I'd thought vibe pumps self-primed and the BZ99 tank is above the pump anyway - wouldn't be the problem?

Just in case the OPV or anything else was the problem I've taken the pump only out of the machine and fed it with a clear vinyl tube from a bottle (I can see water at the inlet and there should be reasonable pressure) - the best I can get is a spluttering few drops out with the new pump.  I've tried all combinations of the old & new pumps and diode's direction.

Sigh - naturally I'd thought "how hard could it be" - meh.

Any thoughts on what I'm doing wrong?

Other than replacing/rotating the diode I haven't done anything electrical as yet - I suppose it's possible that failing switches or the pump over-temp thermostat could be causing a problem.  I guess I should test the voltage at the pump next?


Many thanks in advance for any insights.
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Comments

  • Koffee_KosmoKoffee_Kosmo
    Have you tried the pump by itself in isolation ? I feel it's a blockage somewhere after the pump to the group head KK
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  • C-manC-man
    somethings blocked... Like KK says take everything off the pump and see if it works, then one at a time start re-connecting until you find what is blocked it is basic plumbing, don't over think it....
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  • paranomiaparanomia
    on 1394949270:
    Have you tried the pump by itself in isolation ? I feel it's a blockage somewhere after the pump to the group head KK
    Many thanks for the quick replies - sorry, I forgot to mention that when I was running the pump out of the machine I also had a clear vinyl tube from the outlet (so I could see what was happening). I'm back to thinking it must be the diode (despite buying a new one) - currently reading that testing diodes isn't as simple as I'd thought.
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  • LacehimLacehim
    Paranomia, It sounds like it might have air in there preventing it from priming, or as per this guy you might have overdone something putting it in.  Make sure you can suck water through your hoses, connect one to each end, in from a tank, out to a bucket and test that way.  Once you confirm you have a working pump then move on to testing the rest of the pumping. Also is this a "new" pump or a second hand replacement pump?
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  • Koffee_KosmoKoffee_Kosmo
    The next issue in the assessment line is the control box KK
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  • LacehimLacehim
    Also I read a post with someone that had a similar issue.  they mentioned a bypass valve that was stuck. KK, If the pump is getting power I doubt it would be electrical, more to do with the pump internals, plumbing issues or a blockage somewhere.
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  • QM0996QM0996
    If the pump is running = its working..  You need to split the system... 1: Output of pump to a bucket and see what happens...  ( PS it will run with a good squirt so make sure the tube is fixed. Water and electrons work well to kill you) My $ is on a blockage or failed solenoid in the path to the group head... 2: Input of pump to a bucket of water... This will check the pump.
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  • paranomiaparanomia
    on 1394955944:
    Also is this a "new" pump or a second hand replacement pump?
    It certainly looked 'spankin new (sourced from Bombora via local reseller).
    on 1394960419:
    If the pump is running = its working.. 
    I _think_ that with a stuffed diode that may not necessarily be true - (thanks to google I now know that) a diode normally fails short - with both cycles getting through, the pump will be making noise but not moving water (from re-reading problems on Home-Barista).  That's nice in theory but I just re-tested the old diode and it looks OK - so maybe not the problem.  Testing the new diode will have to wait till next weekend. (very useful pump dissection if anybody is looking, gave me confidence to strip it down - http://www.home-barista.com/espresso-machines/fluid-o-tech-vibe-pump-dissection-photo-album-t19949.html) To clarify - this is (wrt water) how I was testing the pump - outlet to bucket...
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  • QM0996QM0996
    on 1394965070:
    It certainly looked 'spankin new (sourced from Bombora via local reseller). I _think_ that with a stuffed diode that may not necessarily be true - (thanks to google I now know that) a diode normally fails short - with both cycles getting through, the pump will be making noise but not moving water (from re-reading problems on Home-Barista).  That's nice in theory but I just re-tested the old diode and it looks OK - so maybe not the problem.  Testing the new diode will have to wait till next weekend. (very useful pump dissection if anybody is looking, gave me confidence to strip it down - http://www.home-barista.com/espresso-machines/fluid-o-tech-vibe-pump-dissection-photo-album-t19949.html) To clarify - this is (wrt water) how I was testing the pump - outlet to bucket...
    Trust you have not pulled that pump apart ? I have rebuilt >30 and tested many more....  Have seen many more fail due to people playing than actually fail..  I fact I think I have only seen two dead unit and both were open cct on the coil due to excessive running and no thermal reset on the pump.. Every other one was people playing / cleaning /  and or post a de scale and crap in the water tank. Some systems have the diode built in and at the end of the day the diode is to just half wave rectify the AC..... And or like others here, have done; screw in the wrong fitting and smash the one way non return valve. Now this I have seen way to often... And on a quick review of your pic, I am concerned as I can not see the correct fittings attached to the pump...
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  • kiwinickkiwinick
    I've also had a very noisy Fluid-o-tech pump in my BZ99, which also wouldn't push any water. After ignoring the noise for a few days, it stopped completely so I dismantled it in the hope of being able to fix it. Everything inside appeared good, apart from a loose rubber washer (very perished and broken) I found floating around. After searching for a diagram, I found it should be on the outlet end of the piston. It looks like it's supposed to stop the piston from "hammering" into the outlet end of the pump body. I replaced the rubber bit with a new one, and it seems to be working good now, and a lot quieter. I suspect my pump was damaged by being run dry for too long, and the rubber bit wore out and fell off (hence the very loud noises), eventually jamming the piston from moving at which point it stopped. I've since found the reason my pump ran dry - the water tank has a ball-valve on the bottom which wasn't being opened properly, and was starving the pump of water (I noticed a large air bubble in the feed tube, which wasn't moving). The reason the ball-valve isn't opening is because the bottom of the tank has warped upwards and the coupler to the ball-valve isn't fully engaging. I think I can fix this by raising the coupling upwards a few millimeters. I would recommend checking the flow of water from the tank to the pump.
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