clear and concise step by step guide to rebuild. thanks!

Every time I watch one of your videos and you use the phrase "Bob's your uncle" I walk around for the next few days hearing the same "Bob's your uncle" running through my head throughout the day at various times when something or other goes "right". So here we go again ............ Again, thank you for producing some of the finest educational videos on KZread. I'm getting a late start in life but I have enrolled in a basic marine technology course at a local college and just took apart a similar Johnson water pump of a smaller Yanmar engine. Seeing you dissemble it completely was very beneficial.

I'll using a block of wood and giving this a go tomorrow lol! Your video has given me the confidence to take this on!

It's interesting to compare the design of this Yanmar belt-driven pump with sealed bearings, compared to the gear-driven pumps with open bearings in small Volvo marine engines. Those Volvo pumps use engine oil to lubricate the open bearings, so they have a more robust oil seal in addition to the water seal. Both use a weep hole to offer an early warning when the coolant seal begins to fail. Both pumps are disassembled the same way, pressing the shaft out to the drive side after removal of a snap ring that is not accessible until the drive gear or pulley is removed. The orientation of the seals are as one would expect, with the spring of the seal on the side of the fluid that needs to be to contained. So in the Volvo pump the oil seal spring is on the oil side, the water seal spring is on the water side. They are oriented the opposite way compared to each other, with the weep hole between the two seals, to offer an early warning when either seal fails.

best video ever - we sail out of Hong Kong and no one fettle's or repairs anything here anymore - my engine guy just puts in a new pump and throws the old pumps away - Boat is 10 years old and we are on our 3rd pump - no more throwing away I will keep one spare pump and buy repair kits

An absolutely invaluable and really well filmed with a great commentary. I have rebuilt my pump using this help, but used a Yanmar rebuild kit with a new shaft, bearings and circlips plus a new seal. I look forward to a leak free pump this season.

Thanks for the video! I have the same 3GM30F and I appreciate being able to watch these videos and be prepared for similar projects in the future.

Extremely well explained and filmed - thank you!

Thanks, you are a champion. Can't believe you have helped me out with both Triumph engine issues and yanmar raw water pump issues..... I am very grateful.

Great video my friend, live to see the failure point, and the rebuild process, where others would just buy new pump. Learned a lot on the theory of operations. Your friends from Florida

I love how you put the really super helpful suggestion at the very end! I have a leaky pump and need to fix it, thank you for the help

Thanks for this. Am learning a lot about Yanmars from you. Purchased a Beneteau 321 with 3GM30F this spring.

Amazing! There is a video for everything these days. Just notice the same leak today and I was told I would need a new pump. Thanks!

after watching a half dozen film for rebuilding the water pump this is the best!

Excellent video. Appreciate your communication skills - knowing the details to include to address questions, and the added information on rationale and how things work. Seemingly small things that are important. I enjoy your videos. Thank you!

Just found your channel today. Fantastic stuff! Not only do you have the know-how and tools, but you take all that extra time to record and explain along the way. The jobs are taking you probably 4 times longer not including the editing, but you do that for our benefit and I thank you very much. These videos are a great eye-opener to me, as although I'm pretty handy and good with gasoline engines, I'm about to begin sailing my first diesel engine sailboat (Cal 33-2 w/ Yanmar 3GM30). You've given me a ton of information I wasn't aware of. Awesome!

This video perfectly talked me through the job, allowing me to determine quite easily that I was capable of performing it and have the necessary tools, before ordering the parts and committing myself. Bravo! (My pump is attached to a Kohler Genset but the pump is visually identical.

Awesome video. Answered all my questions. I think I just need to replace the water seal on the pump from my Kohler generator but now I know exactly what to look for and how to fix it if I need to. I will be looking for more videos from you!

Thanks for this very helpful video. I am doing exactly the same job on my 2GM20F raw water-non Swedish- pump. Fortunately my bearings look good but leaking was starting through that o-ring seal with the wiring ring in it.Dean

the best video on this subject I found!

Thank you very much for sharing. I have the same leaking and have my pump on the table ready to be disassembled. Now I know how do do (3ym30, similar Johnson pump but not exactly the same)

Very good, well explained video that a layman like me can understand. Thanks for this

Very well done video! Thanks for all the extra little tips and tricks too.

Very helpful, my pump is a little different but all the parts and steps apply. Thank you!

Very interesting. I always fill the raw water strainer before starting the little Kubota engine I have in my canal narrowboat.

Really good video as always. We are now advocating replacing those springs on the "wet" lip seal with a quality O ring two years and 300 engine hours and still no dripping. Sail Safe mate. Ant, Cid & the pooch crew.

@spelunkerd

4 жыл бұрын

Good point! I think it would be fairly easy to push that lip seal out from behind, though the RTV I used may make that a little more challenging.

Excellent tutorial!

Thousands of thanks for your video from Spain :D

Great video! Oh gosh leaking out the weep hole. In my line of work we had (and still have) Cabrio washers that have the top seal fail. That in turn causes it to leak out the weep hole. No fun.

Terrific video - Thank you!

Nice work. Needless to say if you need to get a job done you'd be surprised what a hunk of 2x4 and standard tools can accomplish, but over the years I'm more than happy to splurge on tools to make the job easier.

I do not own a boat or anything that requires a salt water pump, but great interesting video!!!!!!!

I think I can deal with my pump now! Thanks

Thx, that was well done

That’s a great video, I subscribed...

great job thank you!

More Yanmar vids please!

Not to say you'll encounter this issue, but I've run into several discount Chinese sealed bearings that had close to no grease inside them when I removed the seals for inspection. For my use, I've taken to popping the seals off of them and repacking before installation. I don't think I'd spend $90 on a bearing either... :)

Very interesting.

Well done :-D i would imagine a new pump would have been expensive or unobtainum. Also when you repair it yourself you trust it, well i do :-D When you talked about the air in the pump i thought (Manual priming) so it's ready to pump straight away.

One of the best videos I watch on rebuilding this pump thank you

Itching to get out and see how much of this Yanmar I need to service...great videos!

@spelunkerd

2 жыл бұрын

Thank you. What engine do you have?

@zhangminhuang5459

2 жыл бұрын

@@spelunkerd It's a Yanmar 3GM. It starts well, runs well but there is a great deal of oil in the bilge. I suspect the reason I got the boat at the price I did. I am going out to clean it up tomorrow and use some powder to isolate the leakage.

Great vid. Just be interesting to see how long it lasts. It seems to me it is probably a function of how smooth the shaft is where it spins inside the seal.

A " master of all trades " I think we may be long lost brother's Lol.

The press makes extracting the bearings easy peasy and ensures accurate assembly of the new ones. Water gets in everywhere so any sealant is money well spent. Oem parts can be quite expensive to purchase but the alternative must be near equivalent in build quality. Early maintenance procedures eliminates a lot of potential damage later down route 66 and prevents premature launching of the lifeboat. Full steam ahead an dont spare the engines.

Quality

Very nice well thought out video. What brand and model of ultrasonic cleaner do you use and do you like it?

@spelunkerd

4 жыл бұрын

This one was made by Intertek, model CD4860. I'm not sure I'd recommend it, although the price was right and it seems to work fine. In their advertising they note lower noise, targeting the denturist industry. I wonder if reducing noise by using a plastic housing rather than stainless steel may reduce efficacy. If I were to do it again I might upgrade to all stainless and not worry about noise. Volume for ultrasonic cleaners is an important question, since bigger volume can handle larger components but you need more cleaning solution every time. Thanks for stopping by, Ben!

Thank you for the excellent video! About the lip seal (11:40), do you have any insight as to why they're installed with the spring on the wet side, as they are? It seems like if they were flipped around the spring wouldn't corrode so quickly and they might last longer.

@spelunkerd

3 жыл бұрын

It might help to consider a goofy analogy. Suppose you had a door facing into the wind. If the door closes one way, the wind will slam the door shut. If it faces the other way, the wind blows the door open. Now consider what happens when you apply water pressure to the lip of a seal. On the spring side, water pressure will hold the lip tightly against the steel shaft. Higher pressure on the spring side causes the seal to be held shut, but if you get high pressure on the opposite side the lip is lifted away from the shaft, causing it to leak more. The spring is designed to squeeze the edge of the seal against the shaft, so you always want the higher pressure to be on the spring side.

Thank you for the video! Could you provide the part numbers for the hoses you replaced? The part number did not really show up very well on the video. Thanks!

@spelunkerd

4 жыл бұрын

Even at high res, a little washed out and hard to read! The pump hose I have in hand at 13:26 is part # 128690-49010, and the return coolant hose above it is 128695-49530. This applies for the 3GM30FC-YEU engine, you'll want to check the parts list for your engine. These parts lists are available for free online, though there are many updates and revisions depending on year. Your parts supplier may have access to a more updated parts list. Good luck!

Great Video. Thanks. Where do you source the chinese alternatives to the OEM bearings and seals ?

@spelunkerd

2 жыл бұрын

I went to our local NAPA autoparts store.

👍👍👍👍👍👍👍👍👍

Like you said at the end you used a number of machine shop and specialized tools. You also said you could have done the same with a wood board and a regular set of hand tools. I would like to see that video and advice on the following. I have two of these yanmar engines with the exact same pump on my catamaran sailboat and have been buying new pumps every several years for each engine. So I have a number of old pumps that I would like to learn how to rebuild. What is the set of tools I should have to rebuild these pumps onboard, not in a nice machine shop. Thanks in advance, Ricky

@spelunkerd

3 жыл бұрын

There are several videos showing people doing that in the boat. It would really help to have a vise, a 2X4, hammer, a deep socket set to isolate what part of the bearings it is safe to tap on, and needle nose pliers to get those snap rings. It is very important to understand what part of the bearing to press on. For example If the bearing is held on the outside, and you tap on the inside of the bearing, you create torsional forces inside the bearing that will likely destroy it. If that happens you'll likely not notice for a few months, then the bearing will start making noise.

Maybe you could use some sealant to temporary seal any leak? Use Pentax.

@spelunkerd

4 жыл бұрын

Always an interesting question, what to do in an emergency. Fortunately this kind of leak is minimal except when the engine is running, unless the impeller is also damaged. If it leaks when engine is off one could close the seacock. There's a product called 'stop leak' for closed freshwater automotive cooling systems. It often causes more problems than it solves, and it wouldn't work for the open side of a salt water cooling system. I never use it. I suppose one could slop some kind of sealant onto the seal, but you can't let it stick to the impeller (or shaft, where the leak usually is). Most would wait for a new seal, put up with the annoying drip for a short while. A case could be made for having a spare seal on hand for long trips. Thanks for stopping by!

What do you think about reversing the lip seal so the spring isn't in contact with the salt water?

@spelunkerd

Жыл бұрын

Good question, but you don't want to do that. The pressure of the water pushes against the lip of the seal, closing it the same way a gust of wind blows an open door (that swings toward the wind) shut. If the door opens the wrong way, the door is blown open. Similarly a seal put in backwards will quickly fail. There are some seals that are bidirectional, for circumstances where pressures widely fluctuate. In that case they usually have two seals that face in opposite directions. Bidirectional seals are more prone to failure, expensive, and only used in critical applications. Thanks for your comment, I suspect many thought of that and didn't want to ask.

Boaters on boating forums advice using stainless steel bearings for the kind of job but when I ordered replacement bearings from a marine supplier they said non-stainless steel bearings is better. They say stainless steel won’t last as long in this kind of application. I thought corrosion resistance would be important but apparently not. It’s for the exact same pump you disassembled in the video. Do you have an opinion on this?

@spelunkerd

Жыл бұрын

I can't say I know a lot about that topic but I would have thought stainless would be better. Did they explain why not? Perhaps a dissimilar metal problem between bearing and the metal housing? The bearings are separated from the salt water stream by the seal, though no seal is perfect....

On a completely different note. Is there not water in the bottom of your fuel filter?

@spelunkerd

Жыл бұрын

Yes, it's a fuel separator designed to do that. Occasionally I drain the small amount of water from that bottom petcock, but when I do I have to remember to purge any air that gets into the filter during the procedure. To do that, after draining, pump the plunger at the top to evacuate air bubbles. If you don't purge all the air, the engine could suddenly quit because of an air lock. If that happens, to get going again you need to do the procedure I showed in a video of how to change fuel filters. So after draining fuel, run the engine for about 20 minutes at the dock to avoid an unpleasant surprise at sail. You can see a scum layer that forms between the two layers. I believe some of that is fungus which is not good for fuel injectors.

Why not close the salt water seacock at the thru-hull?...

@spelunkerd

Жыл бұрын

Sure, I would do that. Especially with a screw type valve, be sure it closes all the way. With the tubing disconnected, the boat is more vulnerable while you're waiting for parts. Even a small leak over a few days could trigger a frequently running bilge pump to overwhelm its battery power source. If you crack open the strainer, the siphon is broken so salt water won't be siphoned into the boat even if the valve doesn't seat perfectly.

I think the seals fail because the small spring rusts quickly in seawater…

Are you a mechanic?

@spelunkerd

4 жыл бұрын

No, but I play one on KZread, ha ha ha. Automechanics has been a life long passion, which might have been extinguished if I had to do it for a living. Over the course of a lifetime any money saved on repairs has been reinvested back into tools, but I get to keep any wisdom gained. In the end, insight as to how vehicles work is the most rewarding part of the game.

Perfect review of what I need to do on our Yanmar 2GM with the same pump. THANKS! The only question I have is I didn't see you put the 7/16" O Ring back in during the reassembly. I can't really figure out what it's there for anyway and it's behind the seal but not really sealing anything that I can tell. Addendum: The small O RIng seems to be there to block any water that starts to leak from the seal from getting into the bearings. Then the water will drip through the weep hole and, if you are vigilant and notice it first, you could just replace the seal (easy) versus all the bearings etc. (hard). I sourced a kit from ebay. www.ebay.com/itm/112610673142 which had two bearings, a seal, 2 clips. Only problem was the large o ring was too big :-(. I'm contacting the seller and will try to re-use the old one in the meanwhile.