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A quick update - the Sherwood tool I ordered doesn't even fit the impeller threads on my boat. Apparently my impeller (Volvo 21213664 or Sierra 18-30778) isn't threaded 3/4x16, but is probably M16x1.5 (edit - it's M18x1.5 - see below). So, I'm convinced the internally threaded nut tool is a good idea, but can't seem to find specs on any of them as to what the external thread is. I've noticed Johnson Pump makes a very similar impeller tool that is sometimes cheaper and easier to find, but again lacks a good description of what the external thread size is in any of their product descriptions.

John

I use self modified vise grips for pinching off air lines at work. I can't see why these wouldn't work for clamping off the inlet hose during an impeller change.



https://www.harborfreight.com/radiator- ... RcQAvD_BwE

2ridgebacks wrote: Fri May 29, 2020 4:06 pm I use self modified vise grips for pinching off air lines at work. I can't see why these wouldn't work for clamping off the inlet hose during an impeller change.



https://www.harborfreight.com/radiator- ... RcQAvD_BwE

Before crushing the hoses which on mine are the size of a rad hose. You could get like a 2 inch round plug and just plug it.

A plug is a much better idea. Wouldnt want to damage the hose. Some people even just in a rag. On my R5, I dont even need to worry about the water coming in as the bilge can out pump it by maybe 5x, and it only takes 5m or so to swap the impeller.

John - I'll bet one of those Johnson pullers will work. I poked around a bit and also couldnt figure out the threading of your impeller. Hope you can figure it out - are you sure it is even threaded?

The hoses on mine are similar to automotive hoses. It would be difficult to damage them with this tool or something similar.

greenhut wrote: Fri May 29, 2020 6:49 pmJohn - I'll bet one of those Johnson pullers will work. I poked around a bit and also couldnt figure out the threading of your impeller. Hope you can figure it out - are you sure it is even threaded?

Yep, I have the replacement one in hand, and can see the threads. Ordered a cheap M16x1.5 thread converter on Amazon, and will find a suitable bolt for the inner threads if it fits the impeller. I’ll keep this thread updated,

John

Edit - this was the wrong size - see below. It was M18x1.5.

This is a picture of a newer Gen impeller housing.

jhnmdahl wrote: Fri May 29, 2020 9:40 pm

greenhut wrote: Fri May 29, 2020 6:49 pmJohn - I'll bet one of those Johnson pullers will work. I poked around a bit and also couldnt figure out the threading of your impeller. Hope you can figure it out - are you sure it is even threaded?

Yep, I have the replacement one in hand, and can see the threads. Ordered a cheap M16x1.5 thread converter on Amazon, and will find a suitable bolt for the inner threads if it fits the impeller. I’ll keep this thread updated,

I ordered one of the "Johnson style" pullers from Yanmar (the Volvo and Johnson ones didn't specify what the thread size was, so it was hard to choose) in M18x1.5mm, and it fits the threads on my impeller great. Stock impeller is Volvo 21213664, replacement/substitute impeller is Sierra 18-30778, for the 5.7L engine in my 2015 210. Should be the same for the V8 225, 300, and 320, and some others as well.

The Yanmar part number was 129671-92110, cost about $20.
John

Big Block Power wrote: Sat May 30, 2020 9:52 pm This is a picture of a newer Gen impeller housing.

pump looks same as mine, but this is the slightly older newer engine Newer 6.2 (vs the 6.0 I think you are picturing) has a different radiator among other things.

Great write up. I just changed the impeller on my 2014 VP 6.0 380hp yesterday. I have always just had my dealer do it when they winterize it but I forgot to tell them to do it last fall. It took less than a half hour total. The impeller does stick in the housing tight. I am glad I ordered the the Sherwood puller, without it it would have been a bear to get it pulled out! I even used the puller to help get it slid in. The 2 year old impeller looked new yet but it is good peace of mind to have a new one. I even ordered a spare impeller and threw it in the head for a just in case.

I may be cheap, and it may not work, but I had my impeller in the car, took it to a hardware store, and bought a 4" bolt with the same threads and will take vise grips to lake when I try and change impeller. (Talk about a run on sentence). $5.

Great work Greenhut!!!!!!!!!!!!

mdadgar wrote: Fri May 22, 2020 12:19 pm OK, Volvo impeller "special tool" arrived today.


IMG_0460.jpg


I ordered it from marinepartsexpress.com for $15.33 plus $12 USPS shipping.

Haven't tried it yet to make sure it will screw into my impeller, but I will do that and report back.

- Mark

Amazing...or maybe not amazing that a couple bolts are over $15. Of course I paid over $30 for Mercury water pump alignment bolts for an outboard motor. I would have bought the Volvo tool too.

Nicely done guys!

Just want to chime in here and say thanks for the tutorial. I ordered the puller from Sherwood since the Gen 5 V6 uses the same impeller and it was a piece of cake. I was surprised to see a bit of a wear pattern on my impeller from the holes where the water enters and exits the impeller housing. I guess it was good I changed it...

Great write up. One thing to add...sometimes the impeller will "stick" to the housing...I read it's called dry adhesion or dry bonding--the rubber sticks to the housing. I experienced this. I used the Sherwood puller and could only get mine to move as far as the threads woudl go in...it's tough place to get leverage. I read online about someone "bumping" the engine but not starting it to break the dry adhesion--kind of like you would when adjusting rocker arms. As a last resort, I tried it and then the impeller wiggled right out. Just another trick to add to the book as I wouldn't have thought of that on my own.