Wallace Pumps multi-san macerator

Forums › Home Workshop DIY › Wallace Pumps multi-san macerator

Voltaire

2 posts

Wannabe Geek

#236146 19-May-2018 22:18

Hi there. Has anyone had any experience working on these?

We have a 6 year old one which handles all the water from a small flat (sink, shower, basin, toilet, washing machine etc) so it gets fairly heavy use. It's been pretty good to date, but recently started making a nasty screeching noise most times when it ran. My initial thoughts were bearings ... but it turns out that the problem is that the small steel blade has started spinning independently of the pump shaft.

The blade is supposed to be tightly screwed into the bottom of the shaft with some small clearances, but the washer/spacer that was between the screw and the blade has disintegrated, giving about 1mm free space for the blade to rattle uselessly instead of doing its job.

Hopefully Wallace Pumps can supply replacement parts. The 'Service Agents' in the area were not really keen to fix anything and only seemed willing to swap the whole unit for a new one at a cost of about $2.5K. Yikes.

JeremyNzl

359 posts

Ultimate Geek

#2019186 19-May-2018 22:47

Assuming you can get the screw out by locking the shaft,

Hit up any hardware store for a stainless washer, Probably sold in packs of 10, take the screw or measure it to get the internal diameter size.

Maybe some blue thread locker to prevent it undoing and you should be good.

If you cant lock the rotor to get the screw out, There might be a slot for a screwdriver or Allen key at the other end if you're lucky.

Try a cordless drill with the rattle function, SOmetimes they can unwind the bolts without turning a shaft.

Otherwise, you may need to take the top off the motor and grab it at that end job for a sparky possibly.

I don't have one of these just my thoughts on how I would deal with it. Seems simple if its only the washer gone. Assuming you can get that screw out

I know you probably know this already but plz have it disconnected from the electrical supply before any of the above.

GL Jeremy

Fred99

13684 posts

Uber Geek

#2019208 20-May-2018 06:53

I'd be very surprised if the shaft wasn't splined or square or had a flat edge or groove cut in it with a key to lock the blade to the shaft - and if the blade is spinning free, that's probably munted.

I'd also urge caution trying to get that screw out, depending on direction of rotation of the shaft, the screw may have a left-hand thread.

Ge0rge

2052 posts

Uber Geek

Trusted

Lifetime subscriber

#2019271 20-May-2018 10:16

Fred99:

I'd be very surprised if the shaft wasn't splined or square or had a flat edge or groove cut in it with a key to lock the blade to the shaft - and if the blade is spinning free, that's probably munted.

I'd also urge caution trying to get that screw out, depending on direction of rotation of the shaft, the screw may have a left-hand thread.

Judging by what looks to be a chunk out of the leading edge of the visible blade, I would suggest it spins anti-clockwise (as we are looking at the photo) and therefore would be a standard thread.

Voltaire

2 posts

Wannabe Geek

#2019405 20-May-2018 16:42

Thank you for all the responses.

The pump rotates anti-clockwise and the screw is a normal right-hand thread. It required a fair bit of force to remove the screw - but it was possible to lock the rotor by means of an assistant simultaneously jamming a chunky screwdriver into the cast iron rotor blades. The blade and the screw had become worn where they'd been spinning against each other.

I fixed it with a stainless M8 setscrew with a stainless spring washer and a brass washer against the blade. The screw was put in with purple Locktite (low strength) because I want to be able to get it out again easily. The idea being that if the blade hits something really hard (grit, metal, bones etc) then it will slide on the brass washer rather than break something. But under ordinary use the friction should be enough to keep it all together and chop up poop, paper etc.

We'll keep a close watch on it for the next few weeks and see how it goes - but certainly initial tests look good.