Reply
 
Thread Tools Display Modes
 
Old 08-24-2015, 07:53 PM   #1
Guru
 
Insequent's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Insequent
Vessel Model: Ocean Alexander 50 Mk I
Join Date: Mar 2012
Posts: 1,426
Johnson raw water pump leak

I have just replaced the raw water pump on my stbd engine with a spare. It was in a John Deere box, but the pump is a Johnson marked F7B-9. Other codes are 10-24753-01. The spare was US$495, so I suspect it is a similar pump that often gets retro-fitted to Lehman's.

What kind of life do you normally get from these things? At just 375 hours I am thinking that a seal failure is a little premature.

It will be no doubt 'interesting' trying to get a replacement or rebuild in Brisbane now the A$ has tanked big time.
__________________
Advertisement

__________________
Brian
Insequent is offline   Reply With Quote
Old 08-24-2015, 08:14 PM   #2
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
Quote:
Originally Posted by Insequent View Post
I have just replaced the raw water pump on my stbd engine with a spare. It was in a John Deere box, but the pump is a Johnson marked F7B-9. Other codes are 10-24753-01. The spare was US$495, so I suspect it is a similar pump that often gets retro-fitted to Lehman's.

What kind of life do you normally get from these things? At just 375 hours I am thinking that a seal failure is a little premature.

It will be no doubt 'interesting' trying to get a replacement or rebuild in Brisbane now the A$ has tanked big time.
My $495 US(AUD $900 landed) AD L120 replacement pumps are on the boat so I can`t check model nos. The Johnson pump itself is from Sweden. The reason to update is the drive connection on the original can fail unexpectedly,it`s not the pump itself.
When I bought my boat the RW pumps were leaking, and were rebuilt, I`d say that`s the way to go.
__________________

__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 08-24-2015, 08:45 PM   #3
Guru
 
Insequent's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Insequent
Vessel Model: Ocean Alexander 50 Mk I
Join Date: Mar 2012
Posts: 1,426
Local dealer has one for about $850. I found another supplier online, free deliveries anywhere in Australia and they wanted $1724 for the same thing. USA prices seem to be about $500-600, with major rebuild kits (bearing and seal) for $350. I don't have a press so a rebuild kit is not convenient right now.

I will take the old one out to the dealer's warehouse in the next day or so to confirm the one they have in stock has the same outlets. Apparently there there is an upgraded pump with slightly different outlets requiring pipe/hose changes as well.

Still looking for feedback on service life of these things.
__________________
Brian
Insequent is offline   Reply With Quote
Old 08-24-2015, 08:57 PM   #4
Enigma
 
RT Firefly's Avatar
 
City: Slicker?
Country: Bumpkin?
Join Date: Oct 2007
Posts: 9,996
Greetings,
Mr. I. The Johnson pumps on our Lehmans have 1200hrs+ (WAG) on them and short of impeller changes have worked flawlessly. I tend to agree with you that @ 375hrs, a seal failure seems premature. The only thing I could imagine affecting the life of said seal is very silty waters although that would also be reflected in accelerated wear on the pump body itself.
__________________
RTF
RT Firefly is offline   Reply With Quote
Old 08-24-2015, 09:03 PM   #5
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,917
I would think 5000 hours might be possible, 3000 probable and if I didn't get 1500 out of a diesel raw water pump I would be flabbergasted.
psneeld is online now   Reply With Quote
Old 08-24-2015, 09:07 PM   #6
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
Brian, if it helps,we would have done about 450 hours on ours since rebuild.
The $850 replacement sounds good, and you can take the old one in and compare it. A mechanic told me he could get me a pump locally for about $1000, I preferred getting them fully built up from AD. They came with a new hose, part of the redesign.
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 08-24-2015, 09:07 PM   #7
Guru
 
Insequent's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Insequent
Vessel Model: Ocean Alexander 50 Mk I
Join Date: Mar 2012
Posts: 1,426
RTF
When I first noticed the leak I thought it was just the front cover plate. So I removed it, cleaned the O-ring and cleaned the surfaces and re-assembled. There was gritty material on the O-ring and mating faces, so your guess about silty waters could well be correct. When I reassembled, I had no leak at idle. But a few hours run produced about 10 gallons of water into the engine tray so obviously the seal was shot. Hence the replacement. I think I'll buy the local pump but perhaps also import a rebuild kit. It would be about A$500 landed I think. With time I can find someone to do the rebuild for me.
__________________
Brian
Insequent is offline   Reply With Quote
Old 08-24-2015, 09:18 PM   #8
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
My leak was minor compared to the severity of yours. Your two pronged solution sounds ideal. The only problem with rebuilding the old one as backup will be if the new pump has been changed and requires different hoses etc, guess you just keep the old hoses with the rebuilt spare.
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 08-24-2015, 09:22 PM   #9
Guru
 
Insequent's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Insequent
Vessel Model: Ocean Alexander 50 Mk I
Join Date: Mar 2012
Posts: 1,426
Quote:
Originally Posted by psneeld View Post
I would think 5000 hours might be possible, 3000 probable and if I didn't get 1500 out of a diesel raw water pump I would be flabbergasted.
Thanks, I thought there ought to be longer life than what I experienced.
__________________
Brian
Insequent is offline   Reply With Quote
Old 08-24-2015, 09:26 PM   #10
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,917
Quote:
Originally Posted by Insequent View Post
Thanks, I thought there ought to be longer life than what I experienced.
In very silty waters...you could halve those numbers...but it would have to be just about a sand slurry....which I do operate a gasser in and get over 800 hours on a pump regularly.
psneeld is online now   Reply With Quote
Old 08-24-2015, 10:47 PM   #11
Senior Member
 
capt jerry's Avatar
 
Join Date: Oct 2007
Posts: 321
Quote:
Originally Posted by psneeld View Post
In very silty waters...you could halve those numbers...but it would have to be just about a sand slurry....which I do operate a gasser in and get over 800 hours on a pump regularly.
ive a raw water pump for a lehman 120 that needs a rebuild for sale, a rebuild kit from smith is 40$ so they tell me
capt jerry is offline   Reply With Quote
Old 08-25-2015, 01:42 AM   #12
Guru
 
Insequent's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Insequent
Vessel Model: Ocean Alexander 50 Mk I
Join Date: Mar 2012
Posts: 1,426
Well I just bought a replacement pump from the John Deere dealer, A$847. It is the same pump, so no need for pipe or hose changes. Just put it back into the spares inventory. The guy said the mechanical seal replacement is about $130 and that the bearings are usually fine, so I'm getting them to rebuild it for me rather than importing the full major overhaul kit.

He also said two interesting things. First, folks in the river, like me, have more issues than others. Second, the commercial users hardly ever have issues. So although the silty river water is an issue, so is just sitting there unused. The message is clear - get out and do a lot more hours!
__________________
Brian
Insequent is offline   Reply With Quote
Old 08-25-2015, 02:48 AM   #13
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
Quote:
Originally Posted by Insequent View Post
Well I just bought a replacement pump from the John Deere dealer, A$847. It is the same pump, so no need for pipe or hose changes. Just put it back into the spares inventory. The guy said the mechanical seal replacement is about $130 and that the bearings are usually fine, so I'm getting them to rebuild it...
That worked out well, much easier than getting them in from the USA.
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 08-25-2015, 03:01 AM   #14
Guru
 
AusCan's Avatar
 
City: Adelaide
Country: Australia
Vessel Name: Kokanee
Vessel Model: Cuddles 30 Pilot House Motor Sailer
Join Date: Jul 2012
Posts: 2,097
Quote:
Originally Posted by Insequent View Post
The message is clear - get out and do a lot more hours!


The same can be said with so many components on a marine diesel engine.

It is elapsed time more than engine hours that causes the wear. I have seen very low hour diesels with the main bearings badly etched because they hadn't been turned over for long periods of time. Chemical reactions occur damaging the bearing material while it is sitting idle. Sometimes it is due to galvanic corrosion; sometimes an acidic reaction occurs.

Use it or lose it.
AusCan is offline   Reply With Quote
Old 08-25-2015, 03:11 AM   #15
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
Quote:
Originally Posted by AusCan View Post


... I have seen very low hour diesels with the main bearings badly etched because they hadn't been turned over for long periods of time. Chemical reactions occur damaging the bearing material while it is sitting idle. Sometimes it is due to galvanic corrosion; sometimes an acidic reaction occurs...
Thanks for that. Years ago, we used to mess with cars, rebuilding rally cars mainly, we`d buy something to get a low km engine that had been sitting a while, engine would run fine at first but soon begin to burn oil. Happened a few times,I came to expect it, now I know why.
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 08-25-2015, 05:03 AM   #16
Senior Member
 
shufti's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Wine Down
Vessel Model: Riviera 35' FB
Join Date: Dec 2013
Posts: 188
Sorry - late to this thread. My TAMD41A's run Johnstone pumps. I dealt with a catastrophic failure of both shaft seals (age unknown) on my port motors pump. No indication of any problems before journey (bundaberg -> lady musgrave) - only found the water on checking motors before shutting down on reaching Musgrave. As you can imagine - total soupy mess inside the motor. All good after flushing/running/flushing several (5 from memory) times. And liberal use of a shop vac to vacuume the goop out of the rockers after each run.

Anyhoos... I ended up buying a bearing press from supercheaop auto (~$100) and I bought 3 sets of bearings and seals from CBC bearings. Cost $72 for all three sets. (I think Volvo wanted ~$200 for the rebuild kit). I just took the old bearings and seals in, and they measured and handed over the new ones. They alsop gave me rubber o-rings to replace the springs inside the shaft seals - apparently the most common point of failure in saltwater pump seals. I know insequent has already sorted it (sorry I got here late) but thought it worth mentioning for any future forum members searching fro salt water pump help..

Oh - the actual rebuild (using the bearing press) was a peice of the proverbial. Even a numpty like me could (and did) it.
shufti is offline   Reply With Quote
Old 08-25-2015, 05:15 AM   #17
Guru
 
Insequent's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Insequent
Vessel Model: Ocean Alexander 50 Mk I
Join Date: Mar 2012
Posts: 1,426
Quote:
Originally Posted by shufti View Post
Sorry - late to this thread. My TAMD41A's run Johnstone pumps. I dealt with a catastrophic failure of both shaft seals (age unknown) on my port motors pump. No indication of any problems before journey (bundaberg -> lady musgrave) - only found the water on checking motors before shutting down on reaching Musgrave. As you can imagine - total soupy mess inside the motor. All good after flushing/running/flushing several (5 from memory) times. And liberal use of a shop vac to vacuume the goop out of the rockers after each run.

Anyhoos... I ended up buying a bearing press from supercheaop auto (~$100) and I bought 3 sets of bearings and seals from CBC bearings. Cost $72 for all three sets. (I think Volvo wanted ~$200 for the rebuild kit). I just took the old bearings and seals in, and they measured and handed over the new ones. They alsop gave me rubber o-rings to replace the springs inside the shaft seals - apparently the most common point of failure in saltwater pump seals. I know insequent has already sorted it (sorry I got here late) but thought it worth mentioning for any future forum members searching fro salt water pump help..

Oh - the actual rebuild (using the bearing press) was a peice of the proverbial. Even a numpty like me could (and did) it.
Still good info, never too late! If my starboard engine's pump fails soon then I'll be following your solution for sure.

It was by chance I found the tray below the engine half full of water, investigated and addressed it before failure. I was still getting good flow out of wet exhaust. There was a tell-tale green discolouration of part of the pump, between where the seal is located and the bearing assembly. The green of course was salt water reacting to copper in the bronze casting over a period of time from a small leak. I'll be watching both pumps closely from now onwards.
__________________
Brian
Insequent is offline   Reply With Quote
Old 08-25-2015, 05:25 AM   #18
Senior Member
 
shufti's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Wine Down
Vessel Model: Riviera 35' FB
Join Date: Dec 2013
Posts: 188
The water from mine was pouring out the tell-tale in the pump hiousing. Squirting strait through the dead seals into the motor. Joy. Made me sick to the stomach (litterally - came close to hurling) when I looked into the engine bay and saw it. Visions of 2 figure boat dollars dancing through my brain.

For what it;s worth - that was about an 8hr steam at ~7knt (~2100 rpm) with a 5 minute squirt to get through the musgrave entrance on an outgoing tide. Motor didn;t miss a beat the whole trip. Temp and oil pressure remained rock-steady at their normal levels. The olny indication of the failure I had was when I actually saw the water.
shufti is offline   Reply With Quote
Old 08-25-2015, 07:03 AM   #19
Guru
 
AusCan's Avatar
 
City: Adelaide
Country: Australia
Vessel Name: Kokanee
Vessel Model: Cuddles 30 Pilot House Motor Sailer
Join Date: Jul 2012
Posts: 2,097
Just as a side note, I have heard of people blocking the telltale hole in the pump housing to stop the leak.


Not a good idea. The raw water can then be forced past the oil seal and into the engine crankcase. Best to put up the seawater leaking into your bilge until it can be repaired.
AusCan is offline   Reply With Quote
Old 08-26-2015, 11:47 PM   #20
Guru
 
Insequent's Avatar
 
City: Brisbane
Country: Australia
Vessel Name: Insequent
Vessel Model: Ocean Alexander 50 Mk I
Join Date: Mar 2012
Posts: 1,426
I picked up the rebuilt pump earlier today. All up it was $362, including a new impellor ($75) and $120 in labour. I'm happy. Replaced was a mechanical seal, 2 bearings and a seal. I also got a new mounting gasket.

The ceramic seal had for some reason bound up to its mating surface, the spring then tore up the rubber seal. Seems it was some kind of mechanical failure rather than from just silty water. I now have two spare complete pumps and also two spare impellor kits.

My spare pump did not have the impellor inside, I assume to prevent memory of the vanes that are bent over near the outlet. I intend to store both spare pumps with the impellor removed as well. The parts guy did not seem to think it was all that important to do this. He said to just make sure that I have the appropriate lubricant on the impellor when I do install them and start to use the pump, because it is dry start-up of the impellor that does the most damage to it.

For those with spare pumps, do you store them without impellor's inside?
__________________

__________________
Brian
Insequent is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 10:06 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012