Water Pump Refurbishment - Yanmar 2GM20 Raw Water Cooled)

[SteveIOW]

Am about to refurbish the dripping SW water pump on my 1992 Yanmar 2GM20(C) using a service kit that contains nearly everything other than the pump casting and the V pulley. If you are able to see the attached exploded view you will see that the components mounted on the shaft from the pump body towards the pulley are the Oil Seal, Water Seal Ring, Bearing Cover, Inner Bearing....... My problem is the kit does not contain the water seal ring and I cannot find a part number for it so I can order it separately. Also the water seal ring looks on the drawing to be washer shaped whereas the existing item on the old shaft in this position is a "rubber" O Ring (I could have fitted this myself at an earlier refurbishment).
My questions are:
1. Is there a Part Number for the Water Seal Ring?
2. What purpose of the water seal ring (it is positioned away from the oil seal which stops water escaping from the impeller chamber into the section of the housing containing the drip hole) ?
3. Is the existing O ring the water seal ring?

 

[VicS]

Am about to refurbish the dripping SW water pump on my 1992 Yanmar 2GM20(C) using a service kit that contains nearly everything other than the pump casting and the V pulley. If you are able to see the attached exploded view you will see that the components mounted on the shaft from the pump body towards the pulley are the Oil Seal, Water Seal Ring, Bearing Cover, Inner Bearing....... My problem is the kit does not contain the water seal ring and I cannot find a part number for it so I can order it separately. Also the water seal ring looks on the drawing to be washer shaped whereas the existing item on the old shaft in this position is a "rubber" O Ring (I could have fitted this myself at an earlier refurbishment).
My questions are:
1. Is there a Part Number for the Water Seal Ring?
2. What purpose of the water seal ring (it is positioned away from the oil seal which stops water escaping from the impeller chamber into the section of the housing containing the drip hole) ?
3. Is the existing O ring the water seal ring?

Yes there is a part number See the parts diagram and parts list below (#9 in this diagram , and called "plate"}.

ITYWF it helps deflect a leak through the seal away from the bearing. It's possible that it has been changed to an O ring. It appears to fit up against the bearing cover.

 

[SteveIOW]

Thank you Vics. Will order part 9 tomorrow.

 

[rogerthebodger]

If you are also changing the bearings see if you can get ss62002RS

These are stainless steel with 2 seals on the bearing should improve bearing life

https://za.rs-online.com/web/p/ball...V3JVQBh25uA_1EAQYAyABEgI0vvD_BwE&gclsrc=aw.ds

 

[vyv_cox]

Sometimes known as a flinger. My later 3GM30F has an O-ring. It does very little, so there is a good chance that your old one can be put back

 

[Daverw]

When I did ours last year we also found the cam plate was also worn, this had to be ordered separately from the overhaul kit.

 

[garymalmgren]

I am a bit confused here.
The OP (SteveIOW) was asking about "My problem is the kit does not contain the water seal ring and I cannot find a part number for it"
On Vic's post
part # 9 in the first illustration is the plate and #3 is the cam.
In the second illustration # 9 is the cam and there is no part identified as the "plate".

If the OP is ordering part 9 it is both the "plate " and the "cam".

The cam will eventually wear and reduce water flow, but I am not sure of this related to Steve's problem.

gary

 

[VicS]

I am a bit confused here.
The OP (SteveIOW) was asking about "My problem is the kit does not contain the water seal ring and I cannot find a part number for it"
On Vic's post
part # 9 in the first illustration is the plate and #3 is the cam.
In the second illustration # 9 is the cam and there is no part identified as the "plate".

If the OP is ordering part 9 it is both the "plate " and the "cam".

The cam will eventually wear and reduce water flow, but I am not sure of this related to Steve's problem.

gary

You are confused by different numbering in the two diagrams I posted . One was taken from the parts list, the other from the workshop manual.

The part the OP is interested in is the part #9 called "plate" in the parts list. but it is #7 and is called "water seal ring" in the manual.

The "cam" is the part over which the impeller blades run. #3 in the parts list (#9 in the diagram from the manual)

l

 

[VicS]

Sometimes known as a flinger. My later 3GM30F has an O-ring. It does very little, so there is a good chance that your old one can be put back

The 3GM30 pump appears to be slightly different. The part in question is in a slightly different position . It is very definitely a "flinger" in the 3GM30

 

[SteveIOW]

Purchased the water seal washer (slinger) as kindly advised by VicS in #2 above. Then reassembled pump with all new parts. Went out to my boat this morning, refitted the pump, started the engine and guess what - water dripping from the weep hole in the bottom of the pump body. Removed the pump and was able to see the problem though the weep hole. The oil seal had come out of the recess in the pump body and slid along the shaft a little towards the bearing. As far as I can see there is nothing to prevent this, other than the seal being a tight fit in the pump body. Is there anything (sealant/glue) that could be applied to the seal to pump body interface to make sure it stays put?

Just one more thing. Can someone please confirm that I have fitted the oil seal the right way round. The seal is there to prevent water in the impeller section of the pump getting to the bearings so have fitted the U section seal with the open part of the U towards the impeller and the flat side towards the bearings. The seems to agree with the pump cross section drawing in the posts above,

 

[Daverw]

Assume you are talking about the oil seal item 8?Is item 7 fitted as this should be held by the shaft against the oil seal. When I rebuilt ours I’m sure the oil seal was first in the housing and then a round ring was fitted against this, then with the bearing cover against the ball bearings nothing could move.

 

[SteveIOW]

The subject of this thread is a Yanmar 2GM20. The cross section in Post 9 is for 3GM30 which is similar but not the same, The item that came loose was the Oil Seal which is Item 8 on the cross section draw in Post 2. On this pump the Water Seal Ring Item 7 does not help keep the Oil Seal in place.

 

[Daverw]

That makes more sense, mine was a 2gm20 as well, the oil seal was a tight fit into the housing and had to be pushed in with a few light hammer taps