Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 25-02-2010, 13:03   #1
Registered User
 
Janice's Avatar

Join Date: Apr 2008
Location: Cruising the Caribbean
Boat: Tayana 37 "SAILACIOUS"
Posts: 201
Images: 3
Perkins Loses Prime

Our T37 has a 4-108 perkins and we are having an intermittent problem
I am hoping one of you has experienced. Every once in a while it
looses is prime from the sea water cooling pump. Steve has to lossen
the front cover and bleed the air out to get the cooling water flowing
again.

Janice & Steve
Sailacious.com
__________________

__________________
Janice
www.sailacious.com
Janice is offline   Reply With Quote
Old 25-02-2010, 13:13   #2
Registered User
 
S/V_Surya's Avatar

Join Date: Mar 2009
Location: Sasafra river,MD
Boat: gulfstar ketch 41 Surya
Posts: 658
Does it do this during operation or after having sat for a time? I go all winter out of the water and when relaunch it primes right away. Is this a new problem? All points to a worn impeller but still pump should be below water line and no prime required.
Hmmmmmm........
__________________

__________________
S/V_Surya is offline   Reply With Quote
Old 25-02-2010, 13:18   #3
Registered User
 
Janice's Avatar

Join Date: Apr 2008
Location: Cruising the Caribbean
Boat: Tayana 37 "SAILACIOUS"
Posts: 201
Images: 3
We are on cruising on the boat so the engine is run almost daily. It always happens while moving and this sometimes happens in rough seas, but not always.
__________________
Janice
www.sailacious.com
Janice is offline   Reply With Quote
Old 25-02-2010, 13:52   #4
cat herder, extreme blacksheep
 
zeehag's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 17,762
Images: 56
Send a message via Yahoo to zeehag Send a message via Skype™ to zeehag
got an airleak somewhere......or impeller.....gooodluck
zeehag is offline   Reply With Quote
Old 25-02-2010, 14:05   #5
Registered User
 
jrd22's Avatar

Join Date: Jan 2008
Location: San Juan Islands, WA
Boat: 1988 Brewer Three Seas 40' Pilothouse
Posts: 251
"While moving." Do you mean sailing or is this happening while the engine is running. Have you changed the impeller since the overheating problem started? How old is the pump itself, could be worn?
__________________
John Davidson
S/V Laurie Anne
1988 40' Brewer Pilothouse
jrd22 is offline   Reply With Quote
Old 25-02-2010, 14:16   #6
Registered User

Join Date: May 2008
Location: daytona beach florida
Boat: csy 37
Posts: 2,844
Images: 1
also make sure there are no leaks coming into the pump - meaning the intake hoses or, more likely, the raw water filter. have you changed the seal on the raw water pump?

some boats 'bounce' the intake thru hull out of the water in mild or heavy seas and that would possibly inject some air into the system.
__________________
onestepcsy37 is offline   Reply With Quote
Old 26-02-2010, 03:05   #7
Registered User

Join Date: Oct 2009
Location: australia
Posts: 467
Face plate might have excess wear turn over or replace also check gasket thickness if not genuine one, newspaper thickness works well also put a smear of siicone or grease over cam securing screw.

Cheers, Shakey.
__________________
shakey doug is offline   Reply With Quote
Old 26-02-2010, 04:29   #8
jzk
Registered User

Join Date: Jun 2006
Posts: 639
She said it always happens while moving and sometimes in rough seas. Where is the location on the hull of the water intake seacock? I bet that it comes out of the water when you heal and you loose the seal. Our rear airconditioner does this.
__________________
jzk is offline   Reply With Quote
Old 26-02-2010, 08:12   #9
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
First step is to replace both impeller (again even is done recently) AND face plate. If the plate is thick enough, sand it flat again or turn it to use the other side after sanding any marks or text off it.

If that doesn't help, replace the pump and have the old one overhauled and add it to the spares locker.

Every impeller pump is self priming with very good lift capacity so when it doesn't something is worn or broken.

cheers,
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 26-02-2010, 08:29   #10
Senior Cruiser
 
Randyonr3's Avatar

Cruisers Forum Supporter

Join Date: Nov 2007
Boat: Beneteau FIRST 42
Posts: 1,836
Mine started giving me trouble and showed up on the tempeture guage in an over heating problem.. changed the impeller twice without any difference.. went to British Marine in Oakland and after they inspected it, found the shaft and housing was worn.. didnt like the price of the new unit but after installing it, the problem was gone......
__________________
Randyonr3 is offline   Reply With Quote
Old 26-02-2010, 17:08   #11
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Quote:
Originally Posted by Randyonr3 View Post
Mine started giving me trouble and showed up on the tempeture guage in an over heating problem.. changed the impeller twice without any difference.. went to British Marine in Oakland and after they inspected it, found the shaft and housing was worn.. didnt like the price of the new unit but after installing it, the problem was gone......
Wow... that means you have been using the pump for a long time with less than optimal flow. I say that because the compression-block inside (that compresses the impeller blades as they pass) wears out way before the shaft or housing!

cheers,
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 06-05-2011, 17:42   #12
Registered User

Join Date: May 2011
Posts: 3
Re: Perkins Loses Prime

I would like to continue this thread if I may. You all are describing a problem I have with my Perkins 4108.

When motoring in rough conditions or even moderate swells, my raw water intake sometimes sucks air, so that I end up with an air bubble in the raw water strainer, which the raw water impellor will not suck thru. Resulting in the engine overheating.

To get her running again, I close the seacock, open the lid on the stainer to bleed the air out, then close it up again. At this point I usually prime the impellor with soapy water just to get things moving.

In rougher conditions, this is a bit of a pain. And likely only resolves the issue until the next time it sucks air.

So what I'm wondering is, is there a way to permanently resolve this issue? Should my impellor be capable of sucking the air thru? I'm at a loss. The only thing I can really think of is to move the thru-hull to another position in the hull, something down lower. But I can't imagine that the boat, a Morgan 38, would have such a design flaw.

Any thoughts?
__________________
OTG263 is offline   Reply With Quote
Old 06-05-2011, 20:23   #13
Registered User
 
Dynamo1181's Avatar

Join Date: Jun 2010
Location: Bahamas - Maine
Boat: '88 Passport 41' Magic Moments
Posts: 197
Re: Perkins Loses Prime

I would think that you have excessive wear on the front cover as well as the rear wear plate of the Jabsco raw water pump. When mine begins to wear, I can have the same issues. Rebuild that pump and I bet your problems will be solved.
A
__________________
.............< Alan >..............
><((((º> ¸.·´¯`·.¸¸><((((º>
........AD4HE & KD4LGZ........
Dynamo1181 is offline   Reply With Quote
Old 07-05-2011, 07:59   #14
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,573
Images: 240
Re: Perkins Loses Prime

Greetings and welcome aboard the CF, OTG263.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 07-05-2011, 19:18   #15
Registered User

Join Date: May 2011
Posts: 3
Re: Perkins Loses Prime

Dynamo, I'm running a Sherwood pump, but your point is well taken. Although I have replaced several parts of the pump over the past 2 years (bearings and cam, and have polished the outer wear plate), in the end I have to admit that I don't trust it to perform. I think at this point I shall install a new one, then completely rebuild the old one for the experience and use as a spare.

As you can see, I've been dealing with this particular problem over the last few years. It's only been in the last few months that I realized that there was an air pocket in the strainer and the pump wasn't strong enough to clear it. We'll see what the new one does for the situation. Thanks

And thanks to you Gord for the welcome to the forum.

Cheers!
__________________

__________________
OTG263 is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Perkins irwinsailor Engines and Propulsion Systems 75 12-12-2012 08:02
NOAA-N Prime: "In Just a Few More Hours.... MV Off Topic Forum 1 04-02-2009 03:02
Genset pump prime problem The Mons Engines and Propulsion Systems 9 03-10-2008 18:49
Perkins (again) learningcurve Engines and Propulsion Systems 0 05-12-2005 13:19
perkins irwinsailor Engines and Propulsion Systems 5 27-02-2003 11:14



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 17:51.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.