4.3 GL impeller replacement

USA_boater

Petty Officer 1st Class
Joined
Jul 31, 2018
Messages
275
Planning to do this as soon as I can once I receive the part. I opted for the OEM kit and not the aftermarket that comes with the bearings too and stuff. Assuming my pump is fine, what tips can anyone give me for replacing the impeller (any gotchas?)...I am assuming I need to remove the rear seat assembly to better access the pump??? This is on a four winns horizon 180 '04 model. Thanks guys!
 

Don892

Cadet
Joined
Apr 30, 2010
Messages
9
I have the same boat and motor but an 05. For mine you can pull the bench seat forward after releasing cords underneath it.
Take off panel behind seat right in front of engine. A drill motor with a phillip head bit makes the job much easier. Pull hoses off of pump head, yes there is water in the hoses. Can't remember the size of the bolts that hold on the head but they are small. Pull them out and remove head. THIS Is IMPORTANT. Look and see which way the paddles are bent. The new one needs its paddles going the same way. ALSO make sure you use the lube in the box to lube the pump housing or you will cook the paddles when you start it. Use a new oring on pump head.

Hope that helps
Don 892
 

Misterbulbous

Seaman Apprentice
Joined
Jul 12, 2018
Messages
47
Just throwing this out there for constructive debate....wouldn't the impeller vanes have a tendency to self align? I mean, obviously a little soap or glycerin helpful to lubricate during dry start, but if the orientation was THAT critical, wouldn't this process be mistake-proofed? i.e. directional arrows on the housing?, directional arrows on the impeller? design that only allows assembly in one direction?, etc.

I usually "try" to align the vanes, but i find that even the slightest rotation while assembling to the drive shaft causes a few of the vanes to flop the other way.

It's hard for me to believe that the impeller would retain it's un-orientated state when rotating at several hundred rpm's.

thoughts?
 

USA_boater

Petty Officer 1st Class
Joined
Jul 31, 2018
Messages
275
Thanks guys, good discussion; is there any torque specs I need to know? Also, I ordered the impeller p/n 21951348...is that the right one for a 2004 4.3GL boat made in 2003? I noticed the next version (2005 or 2006 can't recall) seemed to use a different p/n 21951346???

Thanks again
 

Misterbulbous

Seaman Apprentice
Joined
Jul 12, 2018
Messages
47
Link below would be a good place to start. My 2002 5.0 GL-B takes the part number you mentioned above. I would be pretty sure your's takes the same. There's been some debate (here and elsewhere) about the quality or stiffness of the Sierra or Poseidon impellers - in favor of the actual VP part from the VP store. I'm beginning to wonder if the VP ones are truly better. Seems I've had a lot more problems with my recently purchased Sierra one.

http://www.volvopentastore.com/Engi...unc.volvo--session_id.058435607--store_id.366
 

Misterbulbous

Seaman Apprentice
Joined
Jul 12, 2018
Messages
47
Thanks guys, good discussion; is there any torque specs I need to know? Also, I ordered the impeller p/n 21951348...is that the right one for a 2004 4.3GL boat made in 2003? I noticed the next version (2005 or 2006 can't recall) seemed to use a different p/n 21951346???

Thanks again

I'm not aware of any torque spec, but if you're using the brass 5.0mm x 0.8 x 12 slotted head bolts, you'll want to be careful to not break them off. Of course, you'll drop one down into the bilge anyways and have to go buy ONE new bolt, like I do.
 

USA_boater

Petty Officer 1st Class
Joined
Jul 31, 2018
Messages
275
I did some research and read reviews and decided to pay the extra for the OEM part...I saw several other options out there including Sierra. I generally consider Sierra to be top-quality for aftermarket parts but in this case I didn't want to take an changes...for the fuel filter I did get a sierra though. Oil filter I did Mobil-1 from wal-mart (made to better specs than regular automotive filter and the case thickness seems the same as the volvo oil filter that came off it).

I also am hoping that I don't have half the impeller missing and wondering where in the block it is...what do you do in that situation if the old impeller is missing pieces?
 
Top