Jabsco 18590 series macerator sewage pump issues

G

gulfcoast john

New member
Hi Brats! A messy lesson for those few with a Jabsco 18590 series black water sewage macerator pump... there are some issues to be aware of which I'll post as a new thread to make future searching easier.
This pump is widely used in trailer boats (which usually have a freshwater sewage rinse system) and sailboats (where saltwater use causes smelly heads, crusting on pipes, corrosion within pumps etc). The pump housing is held together by 4 incredibly skinny bronze tapped rods which corrode in the corrosive environs of human waste and water (esp saltwater). It doesn't take much Net searching to find unhappy buyers who don't get a year before it shows The Initial Early Evidence of Impending Failure (namely, to fly apart spewing sewage all over everything in the compartment when turned on). The bronze rods corrode and break. If you have one, it will likely be mounted under the galley sink starboard side and be plumbed to to the gravity blackwater holding tank and only used when the diverter valve is set for overboard discharge when at least 3 miles out to sea. Jabsco recently changed out the bronze rods with acorn nuts to stainless steel rods with hex nuts, although there may be old models in the retail pipeline.
The macerator pump looks like this:
https://www.amazon.com/Jabsco-18590-209 ... 18590-0000
The old-style skinny bronze structural rods look like this:
https://www.amazon.com/Jabsco-Self-Prim ... 18590-0000
The stainless retrofit structural rods look like this:
https://www.amazon.com/Jabsco-Older-185 ... 18590-0000
All from Amazon for my conveinience, shop your own fav sites.
BEFORE ever turning on a vintage model not within the 12 month warranty (or even if it is), try turning the acorn nuts with your fingers...if they turn, that bronze rod has broken. I was lucky that only one of the 4 had broken, which allowed a drip leak we could smell but not a sewage slinging festival under the galley sink, where we keep kitchenware etc and you probably do to. I found that boaters more experienced than I advised rebuilding this unit every 1-2 years. For a pump whose job in life is to move sewage, you will very impressed, as I was, at the quality of the gaskets, which are made of very good quality...well, er, ahem...paper. For various reasons including incompatible above -water through hull size I can't replace this pump with a Whale unit. But I'm satisfied with the upgrade and replaced with a new unit (I'll rebuild the old one in the winter as the spare). We also had a minor leak at the diverter valve due to a slightly loose hose clamp when using a Hontoon houseboat pumpout massive pump made to empty 150-gal houseboat tanks. It was absolutely tight to a screwdriver and a Vise grip, but a 5/16 nut driver got another 1.5 turns on it and every other hose clamp down there. Lesson Learned.
I hope any Brats with this unit discovers a broken rod prior to TIEEOIF. It will save you a huge preventable mess.
And get the nut driver.
Happy Boating!
John
 
Although we don't use ours a lot in The Sound, we have used it in Canada where the regs are...uh...less stringent. Getting an extra one on board has always been on the list. This just made me put it up higher in priority. Thanks for the "heads up" (pun intended).
 
Question regarding the end of the OP. How tight is too tight for a hose clamp? I didn't know if screwdriver tight is max or okay to go a littler tighter with socket wrench or nut driver? Probably depends on type of hose/connection. How about the typical engine hose connection?

Jake
 
A nut driver will tighten hose clamps tighter and more easily than a flat head screwdriver. We are not talking about a ratchet which will provide you extra torque. We are referring to a "screwdriver" handle with a nut driver head.

On most installs, you will not be able to over-tighten them; they will brake or the worm will jump out of the slots. However, I have seen some cheap clamps cut into cheap fuel lines due to poor quality controls which created sharp edges on the band. Lousy quality = you get what you pay for. I always double clamp by connections too.
 
Since the cabinet was pretty empty for the Smart Gauge install, no time like the present to repair the macerator, right? Yeah, well getting it out was not as easy as it could be. See here: http://www.c-brats.com/modules.php?...ame=gallery&file=index&include=view_album.php

Now it's out and apart. No broken brass studs. But, I just ordered a rebuild kit. The paper gaskets were toast and the impeller was in need of replacement. Not the kind of job I wanna do again, but clorox and water does wonders. Iplan to mount it 1" higher this time.

:roll:
 
I suspect that the Jabsco macerator pumps are used for economic reasons or space issues.. An other option is the Dometic SeaLand diaphragm pump. These do not seem to have many of the issues, which the Jabsco do, but take up more room. This keeps the pump motor up out of water in the bilge.
410878.jpg


Jabsco and Whale also make similar type of pumps, but may have some of the same issues as the inline Jabsco used on the stock boats where the mounting is dependent on the motor body.

8719999.jpg
 
The best part about switching to a diaphragm type waste pump is that they can be run dry without doing any damage. In conventional impellor type pumps the impellor if run dry can be damaged pretty quickly.
D.D.
 
I had Jabsco macerator pumps on my fish boxes and bottom line - they sucked. I was replacing the pumps almost every year and of course they were in a difficult to access area (even after I had some additional access ports installed). I replaced them with Whale Gulper Grouper pumps and never looked back. The Whale pumps have run fine for 2+ years and I hope they will continue to run as well. I certainly would have replaced them each once if they were the Jabsco macerator pumps. They don't pump out as quickly as the old pumps but they do last longer and that's the experience of many on the net.
 
Well my Jabsco 18590-2092 made it about three years. This is the second of these sewage pumps i've had to pull. Right now it is tripping the breaker and I have no idea why. All the electric motor shops are closed cause of corona so i guess i have to replace it. I bought some POS off ebay that was supposed to be some cheap made in china replacement for this; cheap is right, it wont even pull a vacuum.
So what should I replace this with? thoughts?
 
The shaft has a slotted end. There may be a rubber cap over it. If you can get aa screwdriver on the end, and give it a turn, often this will free up a stuck impeller.

I have a good motor, but several of the brass rods had corroded, so it is only the motor and impeller. If you want the motor, it is yours, along with the other parts. (It came off a SeaLand head, but should be the same motor--I bought the whole head assembly for my son at a Hontoon auction. I put a new motor and macerator on the unit I gave to him.)
 
thataway":pwy5pnaf said:
The shaft has a slotted end. There may be a rubber cap over it. If you can get aa screwdriver on the end, and give it a turn, often this will free up a stuck impeller.

I have a good motor, but several of the brass rods had corroded, so it is only the motor and impeller. If you want the motor, it is yours, along with the other parts. (It came off a SeaLand head, but should be the same motor--I bought the whole head assembly for my son at a Hontoon auction. I put a new motor and macerator on the unit I gave to him.)
Click to expand...

Hi Bob,
I already pulled the pump :sad . The shaft spins fine. I re assembled it. Issue persists. Their is something wrong with that motor. That's most generous of you. How much do you want for it?
 
Conrad,
Your three years may be a record. If you accept Bob’s generous offer of the motor, you’ll only need Jabsco model # 18598-1000 rebuild kit (includes the new SS body bolts that don’t dissolve quite as fast as the prior bronze ones).

Whale diaphragm blackwater pumps are much better designed, and I had excellent luck with mine on the Regal cruiser... but the shape/plumbing is tough for that TC255 location, as Bob previously pointed out.

My own style is to buy Jabscos on sale (I have two in the garage) and a rebuild kit every season. I’m happy if I get a boating season (12 mos) or two out of one. Bob’s idea of a ‘quick connect’ is great for change-outs. There will be change-outs.

You will see lots of web rants about this pump, but most are from saltwater sailors with saltwater flush sewage systems.

Hint: Don’t flush your toilet paper (assuming you have had better luck foraging for that item lately than I have had). We put that item in a baggie in the head and trash it daily.

You COULD convert to a ‘composting’ head if you think hauling a 2g pee tank to the marina toilet every day is more fun than replacing this pump every 2 weeks to 2 years. I’d probably convert, if it weren’t so much fun arguing with AirHead fanatics.

Happy Macerating!
John
 
thataway":2b4xc1jl said:
The shaft has a slotted end. There may be a rubber cap over it. If you can get aa screwdriver on the end, and give it a turn, often this will free up a stuck impeller.

I have a good motor, but several of the brass rods had corroded, so it is only the motor and impeller. If you want the motor, it is yours, along with the other parts. (It came off a SeaLand head, but should be the same motor--I bought the whole head assembly for my son at a Hontoon auction. I put a new motor and macerator on the unit I gave to him.)
Click to expand...

Replace the brass rods with stainless allthread?
Also while its apart put a stainless ball-valve(or bronze) before the pump(will limit the shineola factor next time) I also direct wired mine to the batt. through a relay with #10 agw wire, now the only load on the switch is the relay@<2a. Been that way 6 years now. Hope I didn't jinx myself
:wink:
 
cmetzenberg":1tos9305 said:
thataway":1tos9305 said:
The shaft has a slotted end. There may be a rubber cap over it. If you can get aa screwdriver on the end, and give it a turn, often this will free up a stuck impeller.

I have a good motor, but several of the brass rods had corroded, so it is only the motor and impeller. If you want the motor, it is yours, along with the other parts. (It came off a SeaLand head, but should be the same motor--I bought the whole head assembly for my son at a Hontoon auction. I put a new motor and macerator on the unit I gave to him.)
Click to expand...

Hi Bob,
I already pulled the pump :sad . The shaft spins fine. I re assembled it. Issue persists. Their is something wrong with that motor. That's most generous of you. How much do you want for it?
Click to expand...

Hi Bob,
well, that pump made it all the way up till now. I'm mighty tired of these jabsco 18whatevers. What do you recommend i upgrade too?
 
During ten year major engine maintenance, the shop (Key Marine in Pensacola) went all over the boat looking for issues. They found a cabin light that didn’t work, the failed 24/7 bilge pump breaker that I’d bypassed to another battery, the freshwater pump was inop, etc etc.

I said thanks, I’ll troubleshoot all that.

The Whale freshwater pump was electrically dead at 5 years from install (2 year warranty). I had a spare (they were 40% off on sale) and replaced it.

Since this involves removing everything from the under sink cabinet, I also got a chance to notice this tiny bit of dried ooze on the lower body bolt on the Jabsco 18590 POS macerator pump:

DSC04941.sized.jpg

I trashed the whole pump and replaced it with a spare. Now I only have one spare pump left in the garage, and a prior failed one I can’t disassemble enough to use the rebuild kit unless I take the sledgehammer to it. They have a 1 year warranty and a life expectancy of 13 months, plus or minus two weeks. Hopefully, they’ll come on sale and I can buy ten of them. After that, we might convert to an Air-Head.

Happy Macerating!
John
 
I have owned several Jabsco 18590 pumps in serial. Replaced each one, the last because it quit turning. Turns out it was hair; where did that come from? Anyway on disassembling the pump, after it was removed, those bolts were brass, not stainless and one was corroded.

So I started thinking about using another type of pump. Why keep repeating the same mistake, that's insanity? Looked at the Whale Gulper pumps and they weren't going to fit in. Found several other pumps with the same form factor and operation as the Jabsco. Finally settled on the Surflo 3200, primarily because the inlet and outlet were the same as the Jabsco. Like sticking you hand in a barrel and picking out a random peanut. Anyway, put it in with no overboard mess and we'll see how it works.

If anyone has a idea how hair got into the old macerator I'd like to know. Especially since we only use it for it's intended use, which doesn't include hair.

Boris
 
Back
Top