Volvo 8.1 Water Pump Impeller Change

dennison17

Cadet
Joined
May 26, 2009
Messages
20
I have 2004 Cobalt 240 with the Volvo Penta 8.1 big block. I understand that there is an inherent problem with the water pump impeller on these bad boys, and you should change it each year or two. The operating manual shows this change procedure... and it looks easy (outside of very limited access). Are there any "words of wisdom" or lessons learned that anyone can share on this process?
 

Mike250

Seaman
Joined
Dec 9, 2008
Messages
69
Re: Volvo 8.1 Water Pump Impeller Change

I've never done the change on a Volvo but if it's anything like a Merc. you'll need to use a little dish soap to get the impeller into the housing.
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: Volvo 8.1 Water Pump Impeller Change

Moved this over to the I/O section. More complete info over here for this. Good luck!
 

jesserb

Recruit
Joined
Jun 15, 2009
Messages
2
Re: Volvo 8.1 Water Pump Impeller Change

My impellor just went out on my cobalt 226 with a volvo 8.1. I have been told by my mechanic that it needs changed every year. It is no fun when it does go out. I overheated and had to call it a day. The one year I didn't change it then it failed!
 

Jeepster04

Chief Petty Officer
Joined
Jan 5, 2009
Messages
481
Re: Volvo 8.1 Water Pump Impeller Change

So its ok to put dish soap on the impellers when installing them? I had read its bad to put any kind of oil, etc on it but I never thought of dish soap.

A puller would be handy as heck. I plan on picking one up to make things so smoother.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,581
Re: Volvo 8.1 Water Pump Impeller Change

KY Jelly works nicely...works well with all kinds of rubber :)
 

boatworker1

Recruit
Joined
Jul 1, 2009
Messages
1
Re: Volvo 8.1 Water Pump Impeller Change

On some model 8.1 Volvo Penta sea pumps mounted to the front of the engine and turned by the crankshaft via harmonic balancer and main pulley the housing can "wobble" free and suck air from behind the pump, a difficult symptom to diagnose if you don't know where to look. Yearly impeller changes are just good maintenance. If you have a recurring overheat after getting a fresh impeller try pulling the pump body back and forth and see if it is loose in its pressed mount.
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
9,118
Re: Volvo 8.1 Water Pump Impeller Change

KY Jelly works nicely...works well with all kinds of rubber :)
When you buy a "volvo impeller" the kit should come with it's own style of KY jelly lube;):) dennison17 I have 2004 Cobalt 240 with the Volvo Penta 8.1 big block. I understand that there is an inherent problem with the water pump impeller on these bad boys, and you should change it each year or two. The operating manual shows this change procedure... and it looks easy (outside of very limited access). Are there any "words of wisdom" or lessons learned that anyone can share on this process?
To remove the pump you will need to remove a total of six bolts 2 too the arm bracket from the block going to the impeller housing, And some times you can get away with removing just one bolt and loosing the other real good and just slide the bracket out of the way, So it is easyr to put back on saving you some time and pain because I Know how much room you DO NOT have on your boat that you have:eek: By the way be happy you have a volvo and not a merc for this reason right here;) The other four bolt's will hold on the impeller housing it self, To get to one of the bolt's you need to move the bracket out of the way, You should be abel to see 2 or 3 of the bolt's but there is one for sure you will not see but can get to with the bracet out of the way. To remove the four bolt's you will want to use a 5/16 nut driver handle, It works good for this job, The same tool to remove the water hoses if you need to, Just before you remove the hoses mark them with something so you know they go back on the same way. Also when reinstalling the four little bolt's to the impeller housing do not over tighten them they brake varry easy. You only need to go past stop a little, Hand tight with the nut driver. Good luck, I hope this helps you out some.:)
 
Top