[C38] Changed seawater pump impeller fail

Sun Mar 7 17:07:56 EST 2021

Pierre,
If you haven't cleaned the heat exchanger you should, hopefully it's your
problem, but it needs to be maintained regardless. Some years ago [the
listserve] suggested using a welding rod to ream the tubes inside the heat
exchanger. If you're not familiar, the heat exchanger is a bunch of small
tubes conveying raw water running through a big one that has engine
coolant.

The welding rod works well to ream the buildup in the tubes, but the flux
coating wears off and is a bit of a mess. My heat exchanger sits above and
rear of the engine ( I have a Westerbeke, the Universal was replaced) and
once you wiggle into position is fairly easy to ream. There's also a pencil
zinc on one end that you should inspect/replace regularly. A paper towel at
the far end will catch the crud you ream out. I use my cell phone to photo
the hole ends to assure the occlusions are cleaned because it's hard to get
a good look.

Good luck, have fun...hope it's the problem.
Steve

On Sun, Mar 7, 2021, 4:52 PM charles <charles at finn.ws> wrote:

> Only way I could manage was to enlarge the opening in the port locker
> (sawzall) and then remove water heater (fairly easy) and then put down some
> foam pads and enter head first turning about in port locker.  Make sure
> there is someone on deck to hand you all the tools you didn't know you
> needed!
>
> -------- Original message --------
> From: Pierre Patino <pierre.patino at gmail.com>
> Date: 3/7/21 11:43 AM (GMT-06:00)
> To: Catalina 38 Listserve <listserve at catalina38.org>
> Subject: Re: [C38] Changed seawater pump impeller fail
>
>
> Yes. I think it's downstream from the pump as well. Next weekend's project
> is to figure out the yoga to get in there and inspect.
>
> On Sun, 7 Mar 2021, 6:42 am charles, <charles at finn.ws> wrote:
>
>> It is not the pump!  I am guessing your heat exchanger is most likely
>> plugged.  It sits on the rear of your engine above transmission.  My old
>> one got plugged with zebra mussels that enters system as an egg and grows
>> while engine is off.  There are cleanout ports on exchanger but I opted for
>> a larger one.
>>
>> -------- Original message --------
>> From: Max soto <maxsoto at gmail.com>
>> Date: 3/6/21 6:44 PM (GMT-06:00)
>> To: Catalina 38 Listserve <listserve at catalina38.org>
>> Subject: Re: [C38] Changed seawater pump impeller fail
>>
>> Really weird.  Those pumps are, or supposed to be self priming for up to
>> 6’. How old is that pump?  Look for wear in the housing. Somethings the cam
>> might need to be replaced
>>
>> Regards,
>> Max Soto A.
>> +506-8312-1367
>> Alajuela, Costa Rica
>>
>> On Mar 6, 2021, at 14:04, Pierre Patino <pierre.patino at gmail.com> wrote:
>>
>> 
>>
>> OK, new information (and I may be an idiot too!).
>>
>> I got a pressure gauge to measure the output at the Oberdorfer raw water
>> pump. I was able to estimate around 8-10psi  (the needle jumped back and
>> forth due to the nature of the pump mechanics) so I thought that seemed OK.
>> I have yet to find the pressure specs on that pump so I'm not sure. The
>> flow rate into the bucket as stated earlier is definitely "enough" and
>> around 2-3gal/min so I believe that's close to spec.
>>
>> I then hooked up the dock water line to the outlet hose which leads to
>> the heat exchanger. Using the least amount of water pressure I could muster
>> by barely squeezing the sprayer's handle (sprayer was coupled to the hose
>> via a barbed fitting) I was able to see water coming out of the exhaust. So
>> now I'm back where I was, completely perplexed.
>>
>> I thought about something a colleague at work said: "did you purge the
>> line?".  Well, I've never done this before when changing the impeller so I
>> thought "why not?".
>>
>> I was extra careful when disconnecting the dock's water hose from the
>> hose to the heat exchanger and I kept my finger in place to keep the water
>> from spilling out. I also raised the other end of the intake hose above the
>> water line. I carefully fitted them together and then tested again.
>>
>> Amazingly, this worked! Water flowed out of the exhaust for several
>> minutes after turning the engine on.
>> Problem fixed? Time will tell.
>>
>> Questions:
>> Am I an idiot for not purging the line? I've never had to do that before.
>>
>> Also, I paid close attention to the water coming out of the exhaust. The
>> flow is  quite uneven. A bunch of water comes out and then much less and
>> then a bunch more and so on. Is this expected?
>>
>> Thanks again!
>>
>>
>>
>>
>>
>> On Tue, Mar 2, 2021 at 8:33 PM Max soto <maxsoto at gmail.com> wrote:
>>
>>> Wow, honestly this is a though one..  years ago I had a persistent
>>> problem that there was no water in the exhaust, but it happened every now
>>> and then...  turned out it was a little piece of mud or barnacle that was
>>> trapped between the thruhull strainer and the barbed fitting on the other
>>> side of the valve.  That piece seemed to have life of its own. I blowed air
>>> through the hose and easily heard the bubbles coming out on the water, so I
>>> thought the intake was not the problem.  This piece was freely moving in
>>> the thruhull and clogged the intake every now and then. .. just my two
>>> cents.
>>> Regards,
>>> Max Soto A.
>>> +506-8312-1367
>>> Alajuela, Costa Rica
>>>
>>> On Feb 8, 2021, at 20:44, Pierre Patino <pierre.patino at gmail.com> wrote:
>>>
>>> 
>>>
>>> Hello All
>>> As the subject implies, I failed to do this properly I believe. I bought
>>> the replacement impeller parts and removed the old one. Removing the old
>>> impeller was easy. I cleaned the cavity (there was some salt buildup, my
>>> fault for waiting too long)  and when I proceeded to put the new impeller
>>> (looks exactly like the old one), I was unable to put the snap ring back.
>>> I'm not sure how important this is. In any case, I put the cover on with
>>> the new o-ring and started the engine.
>>> Now I notice zero water coming out the exhaust. I feel something's
>>> buggered up and I'm not quite sure what the fastest way to troubleshoot is.
>>> Suggestions?
>>>
>>> By the way, the intake valve is open so I know it's not *that *operator
>>> error.
>>>
>>> I've made sure the impeller spins by running the engine and checking
>>> that the shaft has rotated as well as the impeller (taking the cover off
>>> and putting it back on).
>>>
>>> Just before I started on this project, water did come out of the exhaust
>>> so I know it "used" to work.
>>>
>>> I'm perplexed why I'm having such a hard time with the snap ring. I just
>>> did not want to try jam it in with excessive force. The last time I did
>>> this I had no trouble. Maybe I need to get yet another impeller kit?
>>>
>>>
>>> _______________________________________________
>>> Listserve mailing list
>>> Listserve at catalina38.org
>>> http://catalina38.org/mailman/listinfo/listserve_catalina38.org
>>>
>>> _______________________________________________
>>> Listserve mailing list
>>> Listserve at catalina38.org
>>> http://catalina38.org/mailman/listinfo/listserve_catalina38.org
>>>
>> _______________________________________________
>> Listserve mailing list
>> Listserve at catalina38.org
>> http://catalina38.org/mailman/listinfo/listserve_catalina38.org
>>
>> _______________________________________________
>> Listserve mailing list
>> Listserve at catalina38.org
>> http://catalina38.org/mailman/listinfo/listserve_catalina38.org
>>
> _______________________________________________
> Listserve mailing list
> Listserve at catalina38.org
> http://catalina38.org/mailman/listinfo/listserve_catalina38.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://catalina38.org/pipermail/listserve_catalina38.org/attachments/20210307/3cc3dece/attachment-0001.htm>