Catalina 34

General Activities => Main Message Board => Topic started by: David Comando on May 23, 2021, 03:29:14 PM

Title: Oberdorfer Raw water pump
Post by: David Comando on May 23, 2021, 03:29:14 PM
Let me set the stage: currently my raw water pump is not working. Every 2 years I replace the impeller although I regret doing it as I take out a working one in very good shape and replace it with a $58 new one that currently is not working. (This has happened before.)
I take out the pump shaft with the impeller, remove the snap ring, install new impeller, replace snap ring. I lightly sand the inside of the pump, sand and polish the face plate, install new paper gasket, remove o-ring on pump, polish the face of the pump, reinstall the old o-ring.( i spent 2 hours trying to find a new one, no luck).
Tighten the 4 screws evenly, open the thru-hull, bleed the air out of the pump, and when I start the engine it seems to be pumping at 50%, but maintaining the 158 degree engine temp. I go sailing and when I start the engine to return to the dock, it is not pumping. I make it to the dock before the engine  temp exceeds 180.
The last time it was this bad I replaced the entire water pump, as it was also weeping. This pump is less than 10 years old, not weeping and had been through 4 successful impeller changes.  What is going on?  :?
Title: Re: Oberdorfer Raw water pump
Post by: Jon W on May 23, 2021, 07:28:14 PM
I may have read your post wrong. Are you using both a paper gasket and the o-ring on the cover?
Title: Re: Oberdorfer Raw water pump
Post by: waughoo on May 23, 2021, 08:53:17 PM
I may have read your post wrong. Are you using both a paper gasket and the o-ring on the cover?

I noted this as well.  The paper gasket could cause a problem if there is also an O ring.
Title: Re: Oberdorfer Raw water pump
Post by: David Comando on May 24, 2021, 05:55:49 AM
Thanks. I read the Oberdorfer descriptions on Catalina Direct about the o-ring replacing the paper gasket. I did order an o-ring from them to replace the older one.
On my way to the boat to try again.
Title: Re: Oberdorfer Raw water pump
Post by: Jim Hardesty on May 24, 2021, 06:18:37 AM
Quote
take out a working one in very good shape and replace it with a $58 new one that currently is not working. (This has happened before.)

Happened to me also.  The two impeller failures I've had have both been with recently changed "new" impellers.  My theory is old stock.  FWIW  I now buy only from distributer online.
Jim
Title: Re: Oberdorfer Raw water pump
Post by: scgunner on May 24, 2021, 07:21:40 AM
David,

I change my impeller as part of the 100hr service, it's better to change a good impeller than a bad one, I consider it cheap insurance. I recently had a new impeller fail, the bond between the brass sleeve and the rubber failed so the brass sleeve was just spinning inside the rubber vanes and not moving water. I'd check that first, apparently the Chinese are now making repops. Generally any problems I've had with new replacement for any vehicle parts is because they're made in China. I'd recommend whenever possible you take a little extra time to source OEM parts.
Title: Re: Oberdorfer Raw water pump
Post by: KWKloeber on May 24, 2021, 07:27:38 AM
The paper gasket for the old style (202M pump) doesn’t FIT the o-ring pump (N202M pump).
The bodies and bolt pattern were revised to accommodate the o-ring improvement, which sits on the pump side. There is a cover available that converts the old style 202M into an o-ringed pump (the o-ring sits on the cover side.)

Oberdorfer did have a bad batch of impellers where the rubber detached from the center hub. Also there have been issues with knock-off impellers not sealing against the cover and body.  Always make sure you are getting genuine Oberdorfer impellers.
Title: Re: Oberdorfer Raw water pump
Post by: KWKloeber on May 24, 2021, 07:40:57 AM
>>> I take out the pump shaft with the impeller, remove the snap ring, install new impeller, replace snap ring.<<<

Next time throw away the clip.  Read why on the TechWiki.

You might try extending it to 3 years, it just depends on how much you use the engine and (if you annually lay up) removing it to avoid the fins developing a set to them.  Careful replacing the shaft - use SuperLube on the end and rotate it while inserting to avoid nicking the seals.  Dab SuperLube on the shaft to help prevent the brass hub from seizing onto it.

I wouldn’t be sanding the body of the pump - why? Do you have some sort of build up annually?  The wiping fins should keep it clean.
Title: Re: Oberdorfer Raw water pump
Post by: Ron Hill on May 24, 2021, 07:57:17 AM
Dave : Inspect the old impeller.  Bend each blade and look for cracking where it joins the center.  No cracking, I'd give it a shot of silicone and reinstall it.

What I always did was to take the impeller out over winter layup and put it in a cup under the engine with a shot of silicone.  In the spring I would reinstall it just opposite of the last season so the blades bent in the other direction.

A few thoughts
Title: Re: Oberdorfer Raw water pump
Post by: David Comando on May 24, 2021, 03:00:06 PM
Thanks for all the input. I did remove and discard the paper gasket, re-polished the face plate, removed and inspected new impeller, reinstalled. I noticed that I didn't install the inside washer on the impeller, so I did. Used glycerin as a lubricant. I noticed that when I opened the thru-hull, the  pump wasn't filling with water. So I removed the raw water hose and filled it with water, then reinstalled it. when I opened the thru-hull, water slowly came out of the bleeder.
It took a few seconds for water to pump after I started, but it was pumping well at low speed, faster at 2000 rpm. Engine temp leveled out at 158 degrees and all was well for 15 minutes.
I appreciate all the suggestions. I will purchase OEM parts next time as a kit, impeller and o-ring. I really don't put many hours on the engine seasonally, I work at burning a tank of fuel so I don't have old fuel in the tank.
 I think I'll go 3 years next time!
I go sailing Wednesday, that will be the final test.
Title: Re: Oberdorfer Raw water pump
Post by: Ron Hill on May 24, 2021, 03:04:13 PM
Guys : The best easy lube I found for a new impeller is - liquid dishwashing soap!!

A thought

Title: Re: Oberdorfer Raw water pump
Post by: KWKloeber on May 24, 2021, 04:49:09 PM
Dave

The KIT used to come w/ an impeller, o-ring AND paper gasket (as such it was universal for an old-type or new-type pump.)  The latest dealer info is that Ingersoll Rand (who swallowed up Gardner Denver (who earlier swallowed up Oberdorfer)) decided to discontinue the kit after moving manufacturing out of NY to home base in Milwaukee.) 
Of course, that decision could change at any time!

ipso, the
impeller is p/n 6593
o-ring is p/n 9797-034B
paper gasket is p/n 6599
Title: Re: Oberdorfer Raw water pump
Post by: Noah on May 24, 2021, 06:26:08 PM
They still sell the kits on Amazon that includes an impeller, a paper gasket AND an O-ring together. It is an outfit called Stay Cool Pumps. I bought one back in August.  So that combo kit may contribute to the confusion of using both O-ring snd gasket on the same pump.
Title: Re: Oberdorfer Raw water pump
Post by: KWKloeber on May 24, 2021, 06:53:08 PM


[edited]

Quote

They still sell the kits on Amazon that includes an impeller, a paper gasket AND an O-ring together. It is an outfit called Stay Cool Pumps. I bought one back in August.  So that combo kit may contribute to the confusion of using both O-ring snd gasket on the same pump.



Be cautious.  Very, very cautious.
"They" selling it is not Oberdorfer selling it. 

The Ob kit (p/n 6593K) was discontinued (Depco still offers one as a "build to suit" item (put together in-house, not from Ob.))  But it's a wa$te -- you pay more to include what you don't need anyway.   I lobbied to the marine manager @ Depco for 5 years that he stop duping owners into buying something that is more expensive, just to throw away part of it.

I would be very wary of any seller not stating that it's GENUINE Oberdorfer (is a "Cool Pump" brand.)
LQQks to be an across-the-pond knockoff because the total kit is le$$ than my dealer COST for an impeller alone.

Possibly the source of the non-working setup (w/ gasket) was a knockoff?

-k


[edit]
https://www.cruisersforum.com/forums/f54/be-wary-maybe-of-stay-cool-pumps-impellers-211889.html



Question:Who is the manufacturer of this?
Answer:It is an aftermarket kit. I use quality parts aand package the kits myself.
Thank you,
StayCoolPumps

staycoolpumps Seller · June 2, 2020

Title: Re: Oberdorfer Raw water pump
Post by: Ron Hill on May 25, 2021, 04:47:53 PM
Guys : If there are problems with black Oberdoffer impellers, go to Defender and buy a blue Globe impeller!! 

That's what I have used for many years!!

A thought
Title: Re: Oberdorfer Raw water pump
Post by: Noah on May 25, 2021, 08:45:24 PM
Thx fof the “heads-up” on the Stay Cool” impellers.  I haven’t used it yet as I had purchased it for my emergency spare parts kit. So, it will now be delegated as my impeller of last resort.
Title: Re: Oberdorfer Raw water pump
Post by: KWKloeber on May 25, 2021, 09:18:47 PM
Thx fof the “heads-up” on the Stay Cool” impellers.  I haven’t used it yet as I had purchase it for my emergency spare parts kit. So, it will now be delegated as my impeller of last resort.

SOMEONE needs to watch your back, it might as well be me. :thumb:
Title: Re: Oberdorfer Raw water pump
Post by: David Comando on June 01, 2021, 03:25:07 PM
Thanks again for all the input. Hopefully problem solved. Now on to the next project...and go sailing!
Title: Re: Oberdorfer Raw water pump
Post by: David Comando on June 20, 2021, 05:39:08 PM
The plot thickens...I got the pump working, but the engine was running hot. I removed the upgraded 3 inch heat exchanger, installed 6+ years ago. Blockage was the issue. Boiled it out, I now have great water flow, and an engine that doesn't overheat and maintains a constant 158 degrees. Just in time for a Father's Day sail.
Title: Re: Oberdorfer Raw water pump
Post by: Ed Shankle on June 21, 2021, 03:43:08 AM
As a reminder to all, if your water flow begins to slow and temp creeps up, before pulling the HX and bringing it somewhere to boil out, pull the raw water hose going into the HX and inspect inside the HX nipple. You may find a mineral blockage that you can break up with a screwdriver. It will get you back in business faster. Had to do that yesterday after I noticed slow flow, even though temp was still ok.

Regards,
Ed
Title: Re: Oberdorfer Raw water pump
Post by: KWKloeber on June 21, 2021, 11:54:18 AM

You may find a mineral blockage that you can break up with a screwdriver. It will get you back in business faster. Had to do that yesterday after I noticed slow flow, even though temp was still ok.

Regards,
Ed


If that happens to anyone regularly/often, you might do a stove-top test to verify that the Tstat is opening correctly and also make sure you are running the 160F and not the 180F TStat.

I don't know why but salt deposits at the Hx inlet and water injection wye seems to be more of an issue on the 34 (Actually, I haven't heard of any of our 30 folks experiencing that.)  Maybe the engine is working harder and the whole system runs hotter (more constant/hotter coolant flow to the Hx)?  DUNNO.  :donno:     
Title: Re: Oberdorfer Raw water pump
Post by: Ron Hill on June 22, 2021, 02:42:14 PM
Guys : I've used Lime-A-Way in the intake to the HX every year and let it set for 20? minutes.  It has kept the minerals from building up. 

Do NOT use C.L.E.A.R. - as it's not friendly to copper!!

A thought
Title: Re: Oberdorfer Raw water pump
Post by: waughoo on June 22, 2021, 11:23:44 PM
Is that something you put in through the strainrr or actually remove the delivery hose to the exchanger and pour it in?
Title: Re: Oberdorfer Raw water pump
Post by: KWKloeber on June 23, 2021, 12:46:50 PM
This might be of interest

https://www.practical-sailor.com/boat-maintenance/descaling-solutions-for-boats?MailingID=496&st=email&sc=WIR20210620-MarineCleanersSeries&utm_source=ActiveCampaign&utm_medium=email&utm_content=These+Descaling+Products+Get+the+Job+Done&utm_campaign=WIR20210620-MarineCleanersSeries
Title: Re: Oberdorfer Raw water pump
Post by: Ron Hill on June 23, 2021, 02:54:37 PM
Guys : All I do is disconnect the output line from the Raw water pump.  Then lift it up higher than the Heat Exchange.  Put a small funnel in that line and pour in Lime-A-way.  I pour in enough that I'm sure that it had pretty well filled the HX and let it set for 10-15 minutes.  Then if I have time I blow into that line and empty the HX and fill it again.

I've found that the Lime-A-way get rid of all of the calcium scale!  Easier than disconnecting the HX and having it boiled out!  :clap

A thought