March pump stopped working

[Rundownhouse]

First, I don't know much about pumps and am not handy in general. Hopefully I can describe what's going on clearly and someone can help me out.

I inherited a March MDXT-3. I've been using it to whirlpool. I'll start it recirc'ing the boil with about 15 minutes left to heat sanitize, and then let it whirlpool as I chill with an immersion chiller. After I've finished knocking out, I clean my BK by filling it with water and oxyclean, turn on the burner to get it hot (not boiling) and then let the pump recirc the oxyclean for 15 or 30 minutes or whatever it takes to soak and clean my BK.

I've had a couple problems with my BK intake getting clogged with hops and causing the pump to seize/suck vacuum. I'm always standing there though, and it hasn't run dry for too long at any given stretch.

Last brew session, the pump wouldn't run at all. When plugged in, it would hum, but the head wouldn't turn. So I know its getting power. Today, I took the plastic head off. Without the head attached, when plugged in, it'll turn just fine and sounds normal. When I put the whole head assembly back on, it again would hum but not turn. I then tried just putting the first half of the head assembly on, the part with the (magnets?) encased in plastic and little fan/paddle things. Again, it wouldn't turn. I can kind of get it going if I give the paddles a little shove, but it doesn't necessarily stay going, and it sounds awful, really loud and growling. I wasn't sure if the noise was simply because I didn't have it screwed down tight and the face wasn't on.

In any case, it sure seems the problem isn't with the pump's motor, since it goes just fine without the head. The problem is somewhere between the pump's drive and the parts on the plastic head it is supposed to turn. I guess. It didn't look dirty or anything, but I've got the head assembly soaking in hot water right now just to make sure.

Any ideas what's going on, or how to fix it?

 

[ox1574]

Did you figure out what was going on? I just got two brand new pumps and wired them up. First one works great, second has this humming and the fan at the back won't turn. I haven't opened up the head though to see if there is anything stuck inside that would be causing an issue since it just came out of the box.

 

[Rundownhouse]

Nope, haven't figured it out. Haven't had a brew day since it broke, either.

 

[Malric]

I would try to locate a motor repair shop in your area. I've found that they will often provide diagnostic advice over the phone and in person that may lead you to the cause.

 

[ChuckO]

Search on here for similar problems. I believe that Walter from March Pumps has answered similar problems.

 

[Joesf35]

Is the impeller shaft worn or degraded anywhere?

 

[Joesf35]

Is the impeller shaft worn or degraded anywhere?

Or is the slot the shaft slides into worn our have plastic frayed and sticking out?

 

[WalterAtMarchPump]

Rundownhouse, from what you have posted so far i would guess the motor was dropped (hence the motor "growling") and the alignment is off between the armature and the field coils. Either that or the motor bracket shifted and the drive magnet is rubbing against the rear pump housing. You can send the pump back here to me and i can go through it for you and let ya know whats wrong with it.

-Walter
Send it to:
March Mfg
attn: Service & Repair
1819 Pickwick Ave.
Glenview, IL 60026

 

[wildwest450]

Nope, haven't figured it out. Haven't had a brew day since it broke, either.

I don't think that pump is rated for boiling temps.


_

 

[WalterAtMarchPump]

I don't think that pump is rated for boiling temps.


_

He is right, the MDXT-3 is only rated for temps of 190*F though we do have a "fuge factor" built into it and it would "probably" survive in short exposure applications...

-Walter

 

[Joesf35]

He is right, the MDXT-3 is only rated for temps of 190*F though we do have a "fuge factor" built into it and it would "probably" survive in short exposure applications...

-Walter

Walter,
What parts of this pump are the most sensitive to high temperatures? Does the motor use seals? Just curious

 

[WalterAtMarchPump]

Walter,
What parts of this pump are the most sensitive to high temperatures? Does the motor use seals? Just curious

No seals for the motor. The only "seal" we have is the o-ring for the front cover and those are rated well past the plastics temp ratings. The most critical part of the pump in regards to temp would be the back of the impeller and the rear housing where the impeller sits inside of. During opperation there is a slightly higher temp back there because there is not alot of fluid turn over. Theres a few other factors that can add extra heat as well but not worth going into deatail on...just trying to keep it simple.

-Walter

 

[steinsato]

I'm having the exact same issues with my pump right now. Is there a way to fix it without sending it to IL?

 

[WalterAtMarchPump]

I'm having the exact same issues with my pump right now. Is there a way to fix it without sending it to IL?

Here are the steps to go through when trying to figure out whats wrong witht he pump"

1. Take the pump head off.
2. Turn the power on to the motor and verify that it works by itself.
If motor works proceed to next step. If motor doesnt work stop here and call the distributor you bought it from if under 1yr old, Buy a new motor if you want to fix it....or buy a new pump assembly.

3. Since the motor is working you now have to look inside the pump head and see if anything is causing issues internally. The impeller is the only part that moves inside there. If the impeller is stuck on the shaft it may be due to sugar/crud build up between the two...or pump being run dry. Most times you can force the impeller off and drill it out with a 17/64" drill bit. Worse case you buy a new rear housing and impeller and re-use all the old parts.

4 If everything else up to this point looks OK then the only other thing that could be causing issues would be the alignment of the motor bracket. Most times you can tweak it by had by just loosening up the 4 screws that hold it to the motor and lightly tapping the bracket with the handle of a a screwdriver till it runs. (This is with the entire pump put back together and plumbed up and filled with water)

If all this is above your head then easiest thing would be to just send it back to me here and i can look at it for you.

-Walter

 

[steinsato]

Thanks Walter, I took the pump head off and it did in fact still work without the head. So I put it back on and it made the screeching noise, so I readjusted it a bit filled it with water and it seems to working again. I'm glad I was able to fix it on my own because I didn't notice it wasn't working til I had already mashed in and can't really finish the brew day without the pump. I think my main problem was trying to start the motor while it was dry. User error...

Thanks again.

 

[WalterAtMarchPump]

Just an FYI to anyone else....do not start the pump with out any liquid in it!! it will make a loud screeching noise and next you will be on the phone calling us here thinking theres something wrong with the pump! Thats a normal thing for it to do without liquid in there for lubrication! The impeller is actually bouncing aroudn inside the pump head causing all the noise....Do not do that too long or you can damage it! Get liquid inside before startup!

-Walter