Help with Yanmar 3YM30AE raw water pump

[B4A]

My water pump">raw water pump was leaking.

I started disassembling it, thinking the culprit was the lip seal.

It was not, the spring inside the lip seal looks all right.

Could it be the ballbearing?

The raw water pump shaft has some play, like 1mm. Is it normal to have some play once you remove the lip seal?

https://vimeo.com/user27386372/revie...970/5bbf01b2fc

[Wotname]

Can't view the link from here!
The lip seal is the primary seal so if the pump is leaking, the lip seal needs replacing. The spring may look OK but the seal is between the seal material (nitride ect) and the shaft. The seal material may be damaged or hardened. The shaft may be scored or worn or otherwise not true.

There shouldn't be any side play in the shaft, if there is, replace the bearing(s).

[Jim Cate]

With that much play in the shaft even a new seal will have difficulty sealing. Replace both bearings and the seal. I would expect that seals and bearings are available from normal industrial supply houses for much less than Yanmar will want for them.

And ask the folks who sell you the seals to replace the springs with an o-ring... lasts better than the metal spring.

Jim

[jamhass]

Originally Posted by Jim Cate

And ask the folks who sell you the seals to replace the springs with an o-ring... lasts better than the metal spring.

Jim

Especially important if the (common) new seal has spring steel springs. The ones for marine use have SS springs, but they are not as readily available. Replacing the spring with an o-ring is a great (and normal) alternative.

[B4A]

Thank you everyone!

I'll replace the ball bearings. Hopefully I can find something that fits because I don't have access to Yanmar where I am.

Question: The lip seal from Yanmar was incredibly expensive (USD40.00) last time I bout one. On eBay, I see the same lip seal at USD8.00 with the only difference being that the the Yanmar spring in Stainless Steel with copper whereas the eBay one is just Stainless Steel.

How good do you think thatwould be compared to the OEM?

I read about replacing the spring with an O-ring, do you know if this is just a in the field emergency repair or do you have first hand experience on this and how long will it last?

[EmeraldCoastSailor]

Lip seals for my 3ym30 raw water pumps are $12.50 from my local Yanmar dealer. I have found when the seals fail and I notice water leakage the whole pump will be damaged beyond repair (in comparison to a new pump - about $225 for me) in short order. Once, I did manage to catch one leaking and was able to replace the seal with no damage to shaft or bearings. Now I replace them yearly to preserve my pumps.

[Phyrcooler]

Curious the number of hours on your pump. The 3YM30AE is a fairly new (Updated design) engine. We’re closing on a new-to-us boat that has one, and ironically, it also has a newly installed water pump. Are these a high wear item, or a Yanmar issue?

[blubaju]

All suggestions correct, bearings, o-rings, lipseals, all standard industrial parts, lipseals & bearings always go together, just look for a bearing company

[SV-Viento]

FYI this is a super common problem with this pump. I rebuilt and replaced this pump as others have suggested. We were cruising so kept the rebuilt one as spare and installed a new. Local Yanmar mechanic suggested verifying belt alignment and not over tensioning the belt. Apparently over tightening Belt can unevenly load one area of seal eventually causing leaks. Super common problem with tons of info on net to help you sort it out. BTW I Absolutely loved this engine but this $300 part is a bit of a weak link.

[chasfgr]

Rather than flounder around doing the job yourself, it's probably a better bet to take the unit along to a specialist and get them to do the job - I now always keep a spare, rebuilt raw water pump in my spares having found during 30 years with the boat, that's a cheaper and more effective way of dealing with the problem, shich always happens (in my experience0 in the back of beyond).

The costs last time I had the job done was less than the recommended "kit of parts".

[B4A]

Do you guys also know what other parts will need to be replaced other than the ball bearings and the lip seal?

Does anything else brake in the process to extract the ball bearings? Do I need special tools for getting them out?

[B4A]

Originally Posted by Phyrcooler

Curious the number of hours on your pump. The 3YM30AE is a fairly new (Updated design) engine. We’re closing on a new-to-us boat that has one, and ironically, it also has a newly installed water pump. Are these a high wear item, or a Yanmar issue?

The lip seal is definitely a regular maintenance item that should be specified in the Owner Manual, just as they recommend replacing engine oil and filters. But nowhere in the Use(less) Manual there is any mention of the lip seal.

Other than that, unless you tension too much the v belt after you replace the lip seal, the ball bearings should not fail.

[B4A]

Originally Posted by chasfgr

Rather than flounder around doing the job yourself, it's probably a better bet to take the unit along to a specialist and get them to do the job - I now always keep a spare, rebuilt raw water pump in my spares having found during 30 years with the boat, that's a cheaper and more effective way of dealing with the problem, shich always happens (in my experience0 in the back of beyond).

The costs last time I had the job done was less than the recommended "kit of parts".

I do carry a spare water pump on my boat. Giving it to a specialist is not an option for me, I live off the grid.

[EmeraldCoastSailor]

Originally Posted by B4A

DDo I need special tools for getting them out?

I made a wooden jig to facilitate punching out the shaft and bearings; a hole in a board with enough elevation to allow the the shaft to tapped clear. I use a retaining ring tool but I bet you could get by with a pair of needle nose pliers.

[B4A]

Originally Posted by EmeraldCoastSailor

I made a wooden jig to facilitate punching out the shaft and bearings; a hole in a board with enough elevation to allow the the shaft to tapped clear. I use a retaining ring tool but I bet you could get by with a pair of needle nose pliers.

Thanks!!!! And what side is the shaft supposed to come out from?