March 809 HS Problem

First off I apologize if this has been addressed. But, I have looked through the forms with no resolution to my problem and noticed that although there are simaler pump problems, it is always when implementing a new pump. My problem is as follows: I've been brewing for almost a year now with a March 809 HS. I do 15 gal batches and the pump has pushed through 25 batches so far. On the last couple of batches, though, it is cavitationing when pumping the hotter liquids coming from the HLT and BK for some reason. At least I think that is what is happening. It pumps a little liquid and then bogs down for a second, then revs higher and then doesn't push liquid any longer. Then I have to turn it off, in which it makes a squeal/grinding noise as it turns off and I must re prime to start again. I have read several forms of this happening in which the individuals increase the inlet flow or they restrict the output flow. My system goes into a pony keg lauter grant and I have a ball valve on the outlet that I restrict the flow with no resolution. All I can come up with is that my pump on the outs as I have gone through many brews without this problem. Does anyone have knowledge of their pump doing this after it gets old and if so is there just some replacement parts I can get? Thanks for the Help

 

Two possibilities:

- the "impeller binding on its shaft" syndrome, caused by deposit build-up. The suggested fix is to take the pump head apart, remove the impeller, and run a 17/64" drill bit through the pivot hole.

- a bit less likely but definitely in the running is the thrust washer that sits on the impeller shaft between the impeller and the pump housing is worn out, resulting in the impeller making contact with the pump housing. You have to remove the pump head to check on the thrust washer condition. Morebeer sells replacement thrust washers for the 809 HS...

Cheers!

 

+1 to what day tripper said but also....

Have you ever just taken it apart and cleaned it?

 

I have to question the thrust washer worn out info. My impeller makes more contact with the rear housing. When I look in the housing I can see where the impeller is rubbing on it. I wonder if in use the impeller makes any contact with the thrust washer at all or if bounces between the washer and housing. That would be a travel of maybe 3/16". Hmmm. Does anyone else see wear on the housing?

 

That wear on the back is normal...the impeller moves around during use. When you have full flow with a good supply feeding the pump, the impeller gets moved to the back.... if you restrict the outlet, the impeller will float neutral. then as the level of the liquid drops and there's less head height feeding the pump, the impeller starts to move forward against the thrust washer as it starts to turn into a suction pump instead of a transfer pump....

 

Thank you for the information Walter.

 

Gosh.. I am having the exact same issue and only used this pump twice .. 2 hrs total run time. Can't wait to see resolution.. I am going to take apart and check for foreign matter.

 

Finally got a chance to take apart the wet end of the pump today. It was fairly clean, no large debris, but a small amount of sludge on the shaft. There was no thrust washer. I'm wondering if it disintegrated over time and made its way into the wort. If this did happen would no thrust washer cause the pump to do what I described above? Non the less I'm going to order a new one and I'll get back with results.

 

Took apart two pumps today also to do a comparison. One good one that pumped recirculation mash for an hour with no problems and no noise.
The other was the one cavitation and making noise after it gets hot liquid through it after a while.
Both were very clean, no foreign matter , spun free on shaft, thrust washers looked fine.
Only difference I saw was that the shaft stuck out a tad further on the good one than the one giving me problems..

At a loss what to do here .

 

cajeffus, if the thrust washer is not there then the impeller can come in contac with the front housing and cause issues...even the screetching noise can sometimes be heard too....you can try a stainless washer from a hardware store in the mean time...just make sure it has a 1/4" hole to fit over the shaft....and it should cure the issues till the thrust washers arrive for you...


TwoDogBrew, Can you post a pic of your setup or maybe email it to me? I can see if theres anything you may need to change on the setup to help you...

 

Walter.. Look at the last two in the album
https://plus.google.com/photos/108423930313055883312/albums/5837437514564241345

Thanks
Jim

 

the shaft sticking up farther wouldnt have any issues...it may be it just wasnt pressed far enough into the housing. From the looks of it you have both pump set up/orriented the exact same way....do you have any difference in plumbing between the two? like extra elbows/fittings etc?

 

Since they get hooked up with 1/2" silicone tubing and 5/8" barb to QDs they are plumbed identical.. The only difference I would see is the head pressure.. The pump that is fine has more head having to push through 50' of 1/2 copper , more tubing and back to MLT.
The one giving issue is one I recirculate HLT water or recirculate wort to whirlpool.