Snowman o-ring for water pump in D6-435-I-F

[Jairaj Chugh]

I did my first impeller change on the water pump on a Volvo Penta D6-435-I-F. I purchased a genuine Volvo Penta impeller kit 21730348 but it came with the wrong o-ring. It came with a smaller round o-ring when what I need is a slightly larger snowman shaped o-ring. It seems there were two water pump housings in these engines and I have the rectangular cover housing which takes the snowman shaped o-ring.

I have attached a photo which shows what I need (left side of photo) versus what came with the impeller kit (right side of photo).

Can anyone tell me the correct impeller kit to purchase. What I found has a cross reference to 21730348 which has the wrong o-ring. Alternatively, can you tell me the correct part number for just the snowman o-ring and a source. I can buy a few and keep them around and just buy the individual impellers next time instead of the kits. Others must have faced this similar issue. Thanks in advance.

 

[Eagle 2]

I'm glad you started this thread, as this is on my winter list of projects, I've already done the Onan/Cummins impeller, this is the last engine room project left for my winter list. I will be watching this one closely, and hopefully you will provide insight and pictures as you did here of the process and tools you used and any challenges you had to overcome. Thanks!

 

[sgeary]

We have the same issue with the D4 engine--there are two impeller part numbers that can be used, but they have different size o-rings. Only one fits our "snowman shaped" o-ring If you believe Grok AI, it says the D6-435IF impeller part number is 3593573.

 

[Jairaj Chugh]

sgeary, the part number 3593573 seemed to cross reference to 21730348 which is what I bought. Correct impeller but wrong o-ring. Any idea what the o-ring only part number should be?

 

[Jairaj Chugh]

Eagle 2,

I made a little write up for myself as I did the change. It was just for myself and not for general publication so if you want it, I can send it to you directly.

The big challenges I faced (other than limited access requiring boat yoga):
1. The old impeller would not come out. I think the metal splines were not greased the last time it was changed. I sprayed WD-40 on the metal areas and left it overnight. I put a lot of soapy water on the rubber parts and bumped the engine several times for 5-6 seconds each time with more soapy water between each engine bump. This was the only way to get the impeller started to come out.
2. Ignore all the talk about impeller pullers at least for this specific engine. My impeller (old and new) did not have any threads so the type that has a bolt going into a nut with a hole doesn't apply. For the Jabsco style impeller puller, I think the limited space won't allow it to work. I used two needle nose pliers, put them on opposite fins and pulled. After examining the removed impeller the pliers did no damage. For next time I am thinking about buying two very small needle nose locking pliers (vice grips) from Harbor Freight.
3. The snowman o-ring did not match what I bought. This is the issue I am trying to get help on in this thread.
4. I saw videos of people pushing in the new impeller using something braced on an engine mount. I didn't have to do that. After using two zip ties to compress the new impeller, it went in very easily. I used the butt of a hammer handle with cloth protection to push it in. This worked far better and easier than I expected.
5. Putting the cover back on you have to be careful that you don't push the snowman gasket out of its groove. Use a rubber safe grease to help hold the o-ring in place such as silicone grease or Super Lube which is what I used.

Overall, I think the lack of easy access is the hardest part of this. I hate that boat and engine designers put regular serve items in such difficult spots.

 

[sgeary]

Here is another website with two different impeller references for the D6-435iF engine. https://d6parts.com/products/impeller-kit-d4-d6-suitable-for-volvo-penta-3593573-3588476
I have also had good luck speaking with the techs at Pacific Power Group. Call them on Monday and have your engine serial number available. They can look up the impeller info by your specific engine serial number. Their phone number at the Kent, WA location near the Fluid Motion factory is:

• Phone: 253-478-7291

 

[Eagle 2]

Eagle 2,

I made a little write up for myself as I did the change. It was just for myself and not for general publication so if you want it, I can send it to you directly.

The big challenges I faced (other than limited access requiring boat yoga):
1. The old impeller would not come out. I think the metal splines were not greased the last time it was changed. I sprayed WD-40 on the metal areas and left it overnight. I put a lot of soapy water on the rubber parts and bumped the engine several times for 5-6 seconds each time with more soapy water between each engine bump. This was the only way to get the impeller started to come out.
2. Ignore all the talk about impeller pullers at least for this specific engine. My impeller (old and new) did not have any threads so the type that has a bolt going into a nut with a hole doesn't apply. For the Jabsco style impeller puller, I think the limited space won't allow it to work. I used two needle nose pliers, put them on opposite fins and pulled. After examining the removed impeller the pliers did no damage. For next time I am thinking about buying two very small needle nose locking pliers (vice grips) from Harbor Freight.
3. The snowman o-ring did not match what I bought. This is the issue I am trying to get help on in this thread.
4. I saw videos of people pushing in the new impeller using something braced on an engine mount. I didn't have to do that. After using two zip ties to compress the new impeller, it went in very easily. I used the butt of a hammer handle with cloth protection to push it in. This worked far better and easier than I expected.
5. Putting the cover back on you have to be careful that you don't push the snowman gasket out of its groove. Use a rubber safe grease to help hold the o-ring in place such as silicone grease or Super Lube which is what I used.

Overall, I think the lack of easy access is the hardest part of this. I hate that boat and engine designers put regular serve items in such difficult spots.

Sounds like fun! 😎 Thanks for the input, I'll probably tackle this after my Haulout in January for Bottom Paint, Shaft packing and our big swimstep hinging project. Maybe a good Feb project in the slip. i"ve got a list going, but appreciate your input on this one. Yea, shoving a 435 HP engine in a place made for a small Yanmar causes for some bloody knuckles, that's for sure! I pulled my Raw water washdownj pump and plumbing out today, as I don't use a raw water wash down, that was a fun Yoga exercise! I'll be putting that pump into service as a fresh water washdown now and plumbing it on the Port side where the water lines are.