Volvo sea water pump problem

jonb

Recruit
Joined
Jun 2, 2009
Messages
4
I hope someone might have some advice for me for my seawater pump problem; this was my first boat (1992 Welcraft Excel 20 SX Volvo Penta). Last summer was the 1st season with this boat and all worked fine. When I winterized by boat last fall all was working fine. The motor is a V-6 4.3-liter, motor model is 430B; I cannot locate the model number as in AQ 290 etc. When I was preparing the boat for this past Memorial day weekend, I installed a new 12 fin 12 spline impeller in the pump even though the old one did not appear damaged just figured it was old. For some reason I am not getting suction up through the outdrive to the pump either through bunny ears or submerging the whole out drive. I have taken hoses loose from the pump, directly ran water into the hose on intake side and it seems to circulate through the t-stat and circulating pump. I have run water the other direction back through the out drive and does not seem to be blocked.
This pump is mounted right on crankshaft harmonic balance pulley. It appears to have 3 Allen bolts to remove. I am at a loss! I never just like to change parts until I figure out the actual problem. The pump housing may be wore out, but the impeller seems to fit very tight and all of the fins are in a bent position all the way around. When I winterized this boat last time I did notice sand in the low side drain plugs on the engine block. This must have existed from when I bought the boat. Inspecting the inside of the pump housing appears smooth and not damaged. Also when I held the bunny ears tight to the out drive and did not let water run out through the bottom round hole it did seem to suck some water but not enough to work properly, I tried that one more time last night and I did not seem to work at all. If anyone knows how to obtain all my proper model numbers that would also be very helpful.

Thanks to any one who might have an idea of what else to do. I am prepared to change the seawater, and circulating pumps with a new stat just for general maintenance in time was my plan. My boat may be sitting for a while.

Jonb
 

texsun

Petty Officer 2nd Class
Joined
Jun 30, 2003
Messages
156
Re: Volvo sea water pump problem

I have to say....usually this kind of post starts off with "my engine is overheating" so I have to ask is your boat overheating...or how did you come to find this problem?
I have an older boat also...when I remove and replace those hoses at the end of the season...they occasionally have ripped. If you have a split or hole in your suction hose you will not have a vacuum and there will be no suction. I would look at each hose/clamp/fitting very closely just to make sure there is no air leak.
Also, I'm not sure about your particular pump...but if you by chance left off a gasket as you reassembled the pump...it would be leaking air....and therefore no suction.
If it worked fine last year my gut tells me to recheck the assembly to make sure you have a good seal at each surface/fitting.

Good Luck
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321

jonb

Recruit
Joined
Jun 2, 2009
Messages
4
Re: Volvo sea water pump problem

Thanks for the quick reply; I will secure and recheck all the hoses and just take it to the lake and see what happens. Usually I have been able to use a large Rubbermaid storage container filled with water and garden hose on full blast inside the container with the outdrive submerged with no over heating problem. This time as soon as I did not see water exiting the exhaust tubes at the back of the boat, I knew something was wrong, so I shut it down and started investigating.

Again thanks to both of you for the reply. If I cannot fix this I will let you know and maybe you might be able to help me get the parts I need.

I appreciate your help and thanks for the link!
jonb
 

boatguya1

Chief Petty Officer
Joined
Apr 24, 2009
Messages
444
Re: Volvo sea water pump problem

Are you sure you didn't switch the hoses when you re-assembled?

James
 

jonb

Recruit
Joined
Jun 2, 2009
Messages
4
Re: Volvo sea water pump problem

Thanks for your reply; I will also re-check my hoses as well but most of these are pretty custom fit by factory. I am going to work on this over the weekend and take the boat to a near by lake where they will let me submerge the boat on the trailer and run it to see if the air leak problem is somewhere in the out drive. I will post what ever the problem is in the hopes it might help someone else sometime.
Thanks,

Jonb
 

jonb

Recruit
Joined
Jun 2, 2009
Messages
4
Re: Volvo sea water pump problem

Update, I rechecked all my hose connections and all were tight. After talking to a friend he suggested to pack a sealer of some sort inside the pump housing and see if that would seal up an air leak. I tried it with some petroleum jelly and it worked. My pump and cam is simply worn out. I thought I would share this if anyone else had a similar problem.

Thank you for all you help.
jonb
 
Top