Jabsco Macerator Pump, design flaw

robertsapp · Feb 7, 2012

Peggie Hall-HeadMistress said:
A shame...'cuz you'd only have go THREE miles outside the Bay, not 9 (I've double-checked that with a maritime lawyer). South FL is the only place on the whole Gulf where it's further than 3...6 on part of FL below Tampa...12 miles in the Keys.

I am curious though...if you never go out far enough to dump the tank, you're not using the macerator, so why are we even having this discussion about how to rinse it out???

Yeah, you might want to see where that lawyer was trained. The Florida Dept of Ecology website says the following:

What are the guidelines for Y-valves?

Under federal law, if a boat has a Y valve allowing direct overboard discharge of untreated waste, it must be closed while operating in all inland and coastal waters.

What are the coastal boundaries for waters in Florida?

Coastal boundary limits are nine nautical miles on the Gulf and three miles on the Atlantic Ocean.

And as for the macerator issue, I'm not the one who said I needed it, in fact I've been sailing around with a busted one for the entire time I've owned the boat. I just asked how exactly one goes about flushing a macerator pump, because there's no practical way I can see to do it, but I was open to the possibility that I was overlooking something.

nick8489 · Feb 9, 2012

Sailgunner said:
What a stupid comment Peggy. I was just adding a option to emptying a holding tank for those of us that have the luxury of having our boats behind our house.

I just thought she was cracking a joke!

Andreas7699 · Feb 10, 2012

Viktor Eysselein said:
I bought in May 2009 a new Hunter 45CC. Both macerator pumps (Jabsco 18950) broke down after less than 3 years despite of only little use. The bolts broke and black water was leaking into the bilge. The motor part gets loose and then the pump leaks. It appears to be a design flaw!

Please notify all Hunter owner friends who have the same pump and ask them to check the pumps frequently.

I hope you have not he same problem!,

Viktor

My macarator model number says 18590-2529. Is this a different model? Yous is 18950.

Regards Andreas

Ralph Johnstone · Feb 15, 2012

Any Chance .........................

Viktor Eysselein said:
I talked to my mechanic: One bolt of the macerator pump was corroded through, one the other macerator pump the bolt was broken but not corroded. Bad design!

Viktor

................... you might be able to get your hands on the bolt that was corroded through ? After getting involved in this discussion, one of the first things I did was to check if the bolts on my Jabsco were SS and they were (non-magnetic). Wondering if you might be able to do the same check. I'm hoping that Jabsco (or their supplier) may have accidentally installed a steel bolt rather than SS.

Rick D · Feb 15, 2012

Ralph Johnstone said:
................... you might be able to get your hands on the bolt that was corroded through ? After getting involved in this discussion, one of the first things I did was to check if the bolts on my Jabsco were SS and they were (non-magnetic). Wondering if you might be able to do the same check. I'm hoping that Jabsco (or their supplier) may have accidentally installed a steel bolt rather than SS.

Interesting. All of mine were what appeared to be bronze. At least I assume it was not brass, but it might have been.

Andreas7699 · Feb 16, 2012

Ralph Johnstone said:
.............. of the failure mechanism on the bolts ? Was it a failure due to mechanical forces or was corrosion the culprit ?

Looking at the installation, is there any chance that the pump body is putting any stress on the motor ............ maybe the motor being solidly mounted and the attached piping being rigid ?

I've got one lurking under a sofa and will be keeping an eye on it. Thanks for the heads up.

Vas it the bolts marked 13 that broke?

Rick D · Feb 16, 2012

Assembly bolts

Andreas7699 said:
Vas it the bolts marked 13 that broke?

Yes, that is correct.

Andreas7699 · Feb 16, 2012

Rick D said:
Yes, that is correct.

Thanks.
Then its a problem, yes. My pump in my H 36 2008 is numbered 18590. It also says it can run dry on it. You seem to discuss model 18950. Are you sure it is 950 and not the 590 as in my boat. They seem very simular.

Regards
Andreas

Rick D · Feb 16, 2012

They are basically the same; just detail & generational differences.

Rene amyot · Feb 17, 2012

All kidding aside, in many cases is impractable or impossible to drain and or flush your macerator pump. Fresh water and sewage is not all that corrisive. No doubt corosion is the culprit. Salt water flushing adds another element as does flushing with muriatic acid if left for extended periods. The bronze/brass bolts used in these macerators is not a design flaw. As in most products for boats limited life spans are designed in, so every two years or so we must shell out for replacements. Stainless bolts might give us an extra year or so.

Rich Stidger · Feb 19, 2012

I have the Jabsco 18590 maserator pump in my '97 h40.5. I have not experienced any breakage of the #13 bolt shown in the exploded view, but I have found that these bolts are a bit too short.

I'm not sure if they are too short in all four positions, bu they are marginally short in at least two of the locations- either 6 & 12 or 3 & 9 spots. In my case if I thread the bolt into the motor body until it bottoms then I do not have enough threads left to install the nut with all of the required washers. If I don't bottom the stud into the motor base then as I start to tighten the nut it causes the stud to spin into the motor base until the nut again cannot be secured.

I have found that I need to start the stud into the nut and then insert the stud into the pump housing and tighten very carefully.

One of these days I am going to measure a spare stud and make up a set or two that are a bit longer. The length is critical- if too long the stud will bottom in the motor housing and also in the cap nut and will not be tight. It would be better to replace the cap nuts with regular nuts and just a much longer stud.

Anyone else have this issue?

Rick D · Feb 19, 2012

Same for me...

Rich Stidger said:
Anyone else have this issue?

Sure did. I changed from the cap head bolts when I replaced the studs last round. Rick D.

Marc14857 · Jun 20, 2012

Viktor Eysselein said:
I talked to the mechanic who exchanged both macerator pumps: one bolt was corroded through, the other plainly broken. it looks like stronger bolts of non-corrosive material ae needed.

Viktor

Just checked my Jabsco 18590 and found out that three of the four studs are spinning freely by hand and I suspect are broken. Pump is 5 years old with little use. Making plans to change it out this weekend. Too bad there isn't a better fix available

Rick486 · Jun 21, 2012

Marc14857 said:
Just checked my Jabsco 18590 and found out that three of the four studs are spinning freely by hand and I suspect are broken. Pump is 5 years old with little use. Making plans to change it out this weekend. Too bad there isn't a better fix available

My 44DS is in the 5th season and I am on my second pump. Only difference is a seal failed on mine before the bolts corroded. Probably because my heads use fresh water. The advantage in my installation is that the pump is at the top of the holding tank so the consequences of a failure are a few drops rather than a stream of blackwater. And I check the thing each time I use it.

btw Marc did you see my boat Maxine against the bulkhead there on Monday-Tuesday. The yard was replacing the headstay fitting from Selden. It went well and the old fitting looked just as pristine as the new one.

Marc14857 · Jun 26, 2012

Rick486 said:
My 44DS is in the 5th season and I am on my second pump. Only difference is a seal failed on mine before the bolts corroded. Probably because my heads use fresh water. The advantage in my installation is that the pump is at the top of the holding tank so the consequences of a failure are a few drops rather than a stream of blackwater. And I check the thing each time I use it.

btw Marc did you see my boat Maxine against the bulkhead there on Monday-Tuesday. The yard was replacing the headstay fitting from Selden. It went well and the old fitting looked just as pristine as the new one.

Hi Rick,

Sorry I missed you as I wasn't up at the boat until Saturday. . I did replace my pump on Saturday and it was not too bad a job. biggest problem was getting the correct fittings at the pump discharge which turns out to be a 1 1/2 inch female elbow and a 1/14 Inc reducer glued into the elbow. After that all went well. Two bolts on the original pump were corroded.

BTW I am at a business mtg in Newport for the next few days and
Caught a glimpse of the 45 ft America's Cup training boats racing off of Fort Adams. Don,t know how fast they were going but they did look impressive. Hope to see more of them this afternoon.

jcockerline · Jan 19, 2013

My 2009 Hunter 41 has the same Jabsco pump #18590-2592 with the same problem - broken bolt #13. I have just purchased a new Jabsco replacement pump with a slightly different serial number - 18590-1000 - but the specs seem to be identical.

Before I install it does anybody know if the change in model number has any significance, or is this simply a newer generation of the same pump?