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Pump Couplings

Cast iron, springs, you know. Do any of you guys change these as a matter of preventive maintenance? One just let go on a customer and it destroyed the bearing assy. What is YOUR method or procedure when you reassemble them? Motor first or pump side first? What causes them to fail? The pump bearings feel ok, I can spin the shaft, no water leaking into them but once I replaced the coupling and ran it up the bearings started to howl something awful. The bearings have been getting a few drops of oil every 4 months.


  • I don`t

    replace them as preventive maintenance, but when I do I use a Spiralink coupler in place of the 4 spring. I understand over/sloppy oiling of the motor allows the rubber mounts to "sag"(the oil reacts with them), causing misalignment of the shaft.
    I usually put the pump side on first, but either way can be difficult if the motor-lead is short.

  • jalcoplumb_7
    jalcoplumb_7 Member Posts: 62
    I try to avoid them.

    99% of the time I end up changing the pump to a 00 series circulator. I give the customer the choice to remove the headache or change the coupling. When I explain that the new pump will not have the same problem they are tickled pink. Most of the time the replacement pump will use less electricity and be smaller then the old one.

    As for the bearing assembly, most of the time a new 00 series is less then the cost of replacing the bearing assembly and labor.

    The best is when they tell you how it was making noise all heating season.

  • Empire_2
    Empire_2 Member Posts: 2,343
    Motor mounts are important.

    This is one of the causes of failure, but not the only cause. 4 drops will not Do Anything. Refer to B&G specs. Lack of oil may be your immediate problem, but who knows. B&G's web sight is awesome and I strongly recommend it for all related problems, as you can find the answers to most of your question. How old is the bearing Assy., and when was the wick replaced?

    Mike T.
  • This is a big one...

    but point well taken, I'll look at it again with that in mind and see if I can get one that will work and throw a price at them.

    Yes, I talked to the guys at Bell Pump in Hartford and they gave me new mounts as well as the assembly but I'm going to hold off and look into the above idea before I go any further. The assembly is maybe 4 years old the motor is much older. Yup, I do pump side first too. Just checking. ;)
  • Rich Kontny_4
    Rich Kontny_4 Member Posts: 73

    There are still alot of B&G three piece circs out there. They certainly have stood the test of time. They are dinosaurs now that cartridge type pumps are available.

    Updating is always an option if the owner can be talked into it.

    Rich K.
  • Couderay
    Couderay Member Posts: 314
    B&G 3 Piece

    Second pump since 1964,rebuilt, now serves as a back up. If it fits, oil once a year and fourgetaboutit. Series 100 on a weil mcclain. Do they still make em like they used too??
  • no they don't make them

    Nope, they don't make them like they use to. I consider those 3 pcs are crapola. I have some jobs that the orginal circ pumps are still in service while the new one since '85 for new addition zone been replaced at least six times over.
  • Good question,,,

    Another simulpost I see, good answer too...

  • hr
    hr Member Posts: 6,106
    power consumption alone

    should be enough to convince the owner to upgrade to a wet rotor.

    Considering the new ECM circs power consumption could be 1/3 to 1/2 with a new circ.

    And maintenance issues disapper.

    hot rod

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  • well,,,

    I'm afraid Taco doesn't have anything big enough so I'm going to have to rebuild. Thanks for the ideas on options!
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    Which circ did you have?

    Can't believe Taco, Grundfos or B&G don't make wet-rotor replacements that big......


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  • tim smith
    tim smith Member Posts: 2,752
    service!!!!!, very easy

    We probably replace at least a 200 - 300 couplers & (motor mounts)the critical stage each year. Service is easy on these and they last a long time if maintained. Oil yearly and every 3 yrs or so couplers and mounts. We don't replace them as matter of course but look at the wear where the spring is tied to cast body of coupler. This will give you a good idea if spring or cast assembly is wearing out. Good luck, Tim
  • I don't have the numbers...

    in front of me but the pump info indicated 47 GPM @ 24' of head and the best TACO could do was 45 gpm @ 18' of head. A "1400" pump we were looking at IIRC.
  • jalcoplumb_7
    jalcoplumb_7 Member Posts: 62
    You sure?

    Are you sure the original is the proper size. As with boiler replacements it is good to check the size needed vs the size that was installed previously. I see a lot of oversized pumps.

    Saved quite a few customers money by installing the right sized pump on the replacement.

  • Joe Mattiello
    Joe Mattiello Member Posts: 707
    Taco 1400-70

    The Taco 1400-70 will deliver approx. 47 gpm @ 21 ft. This pump has a nice flat curve and it's maintenance free. See attached literature for more information on the pump mentioned.
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions
  • Big Ed_3
    Big Ed_3 Member Posts: 170
    Over and Under Oiling

    As Mike has mentioned ,motor mounts are the main cause for couplings failure .If the motor has been over oiled and leaks out on the motor mounts they get soggy . And with the weight of the motor it drops and now the two shafts are offset from one another causing the springs to rotate which would cause a noise and wear them out . Change a coupling ,then also change the mounts or the complete motor as well.

    Under oiling , worn or unplugged wick would dry out the bearing shaft . They use a wick rather then a bath to prevent grit from entering The bearing also has a oil weep hole to prevent over filling .

    Installing the coupling.... First you have to remove the oil one . You don't want to push or pull on the shafts so it it does not want to come off easy enough use a small gear puller .

    The first thing you want to check with installing the new coupling is how easy it slides on the bearing shaft .It should slide right on. If not oil and clean the shaft or rat tail file the coupling opening .

    Small models.... I first install the coupling on the bearing then bring up the motor up while I am holding the motor end of the coupling with two fingers with allan key in place and motor bolts in arms reach .(the bolts in arms reach we all learn the hard way} Align the key to the counter sunk hole and slide the couplings on flush with the shaft. Hold it with you two fingers and tighten up the allen . Only tee handles are useful here Make sure you catch the hole . You can tell by the depth and also the coupling will slide out off the shaft a little .

    Large or problem replacements .. You can use threaded rod or longer bolts to hold the motor temporary in place while you install the coupling .

    Wood Golf tees are use full just incase you applied too much pressure on the shaft and now the weep hole is dripping . You pound one into the hole so it does not leak until the seal re-seats it self or buys you enough time until the bearing oil cavity fills up with water and the next guy get to repair, ............................................................................. OK I'm only kidding here ....Before the B&G Red School House comes down on me :)

This discussion has been closed.