March pump crapped out on me

bought this pump from Austin home brew supply les than a year ago. Brewing tonight on my ag herms system, and luckily I made it through the sparge fine. Went to turn on the pump to flush the lines with water, and the fan just bounces a little, motor hums, but then nothing. It started doing this at the beginning of a brew 2 weeks ago, but it was 25 degrees out and I assumed some water in the line had frozen it....after a minute it started working again.

Anyone know if it's busted, or if there's something I can do to fix it?

i'm assuming your prime was fine. i'd check that no obstructions are inside the pump head. if not they do sell replacement heads and pump fins.

Have you opened the head to check for obstructions?

Well, I disconnected all the hoses and peered into the head....couldn't see anything. Do I actually need to disassemble the head to check it? The prime has been fine when I've been testing it.

Also, how do I know if I need to replace the head or pump fins?

Sorry, I basically know how to plug this thing in and prime it. That's about it.

There should be 4 screws that are on the actual head. CAREFULLY unscrew them. Make sure these aren't the ones that are for the motor. You will be able to remove the head, look at the impeller, clean, it, etc. It'll let you understand a lot about how the pump works/why air bubbles are bad for it, etc. When you reassemble, remember the way everything went and do not overtighten the screws. If you strip the threads, your pump will have to be professionally repaired.

ScubaSteve said:

There should be 4 screws that are on the actual head. CAREFULLY unscrew them. Make sure these aren't the ones that are for the motor. You will be able to remove the head, look at the impeller, clean, it, etc. It'll let you understand a lot about how the pump works/why air bubbles are bad for it, etc. When you reassemble, remember the way everything went and do not overtighten the screws. If you strip the threads, your pump will have to be professionally repaired.

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Very good -- I'll give it a shot tonight.

I think everyone with a march should do this.....it's pretty enlightening; once you see the way the head is channeled, you'll see where air collects and whiy you need to orient it with the output up. Make sure you only take the head off, don't mess with the body of the pump....there's oil, bearings, and all sorts of junk in there.

Ahoy hoy,
Not only do I agree with you Steve, I think folks that dont own march pumps, but are thinking about them, should see too. So, lets show them....
Enjoy....

I almost forgot,
This is just to get the head off. The backplate comes off to get to the impeller. I didnt have access to a photo of it tore apart any farther. But this shows you how the magnetic drive works anyways.
Best I could do, hope it helped a bit.
A great day to you all.

well, I've opened it up and there was no obstruction. I tried plugging it in with the head off (very briefly) and the motor turned fine. Now what?

You removed the backplate as described above, right? You should be able to pull the impeller off the post, and spin it freely, etc. I wonder if your magnet is getting weak?

Sometimes even though I think I have a good prime, I still have to lower the output hose and drain into a small pot to get a siphon going....then the pump usually takes over.

March pumps totally suck. No piece of gear should be such a PITA, especially for what it costs. I really think a high flow peristaltic pump is the way to go...using hi-temp food grade tubing, of course.

My march pump has "seized" on me twice. Both times the culprit was beer stone. Take it apart and soak the impeller in acid such as diluted star san or vinegar. Be careful that you do not lose the tiny thrust washer that sits on the impeller shaft between the pump head and the impeller.

stevehaun said:

My march pump has "seized" on me twice. Both times the culprit was beer stone. Take it apart and soak the impeller in acid such as diluted star san or vinegar. Be careful that you do not lose the tiny thrust washer that sits on the impeller shaft between the pump head and the impeller.

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Would running a good PBW wash on the rig do the same for cleaning? I am doing 30-60 minute hot PBW washes on my rig now, followed by a warm water rinse. I have been running my March pump for a couple years and have not had any issues come up.

ScubaSteve said:

You removed the backplate as described above, right? You should be able to pull the impeller off the post, and spin it freely, etc.

Click to expand...

Yep, and I see what you mean about understanding how it works now. It's actually pretty simple, but I had now idea before.

ScubaSteve said:

Sometimes even though I think I have a good prime, I still have to lower the output hose and drain into a small pot to get a siphon going....then the pump usually takes over.

Click to expand...

I don't think this is a priming issue - the motor should still spin with or with out a prime, and in the two cases where it has quit working it did have a prime, the motor simply didn't want to turn.

stevehaun said:

My march pump has "seized" on me twice. Both times the culprit was beer stone. Take it apart and soak the impeller in acid such as diluted star san or vinegar. Be careful that you do not lose the tiny thrust washer that sits on the impeller shaft between the pump head and the impeller.

Click to expand...

I'll give that a shot.
The pump is working currently....I have no idea if it just needed some time, or if bringing it out of my 25° garage helped, or if taking it apart and putting it back together magically "fixed" something. I also went ahead and bought some oil for it and put a few drops in since I had never done that before.

Guess I'll cross my fingers--I just don't want it to quit on me in the middle of a brew session. That would be......bad.......

I just want to bump this post to give a big thank you to everone who responded to this thread. I am brewing right now, and after the last 20+ batches went fine my March pump seized up on me again halfway through my sparge. I started to panic, but then remembered this thread, looked it up, and fixed the problem. Lost 20 minutes while I disassembled/reassembled the pump, but that is nothing.

A huge thank you to these forums and the people who responded to this thread a long while back.

Don't forget about oiling the motor, mine acted up and wouldn't turn, but a few drops of oil in the oiling holes and I was back in business, and this is on a new pump that had been run only 5 hours.

I had this happen and fixed it by loosening the set screw on the shaft the magnet sits on. I then pushed it as far back as it would go and made sure it was aligned. No problems since that.

bendavanza said:

Don't forget about oiling the motor, mine acted up and wouldn't turn, but a few drops of oil in the oiling holes and I was back in business, and this is on a new pump that had been run only 5 hours.

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Where are said oiling holes? Thanks.

TB

Thanks luckily I had an extra pump since I only use one and own two, but this thread saved me $150

Tiber_Brew said:

Where are said oiling holes? Thanks.

TB

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At either end of the motor case. Mine has them marked on the ID sticker.

From the ones i get back here with the complaint of "Humming" or " buzzing" it usually turns out the motor was dropped or something fell on it and tweaked the motor case throwing the entire shaft/rotor assembly out of alignment. I have had some prety good luck getting them straightened out and running again as of late...
If you have the pump head off and plug in the motor does it give off a small buzzing noise just at start up then go away as it gets up to full rpm? either way if you are having problems just shoot it over to me here and i'll check it out no problem....