Lip seals for my 3ym30raw 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.
$12.50? That's a great price! Where are you located? What's the name of the dealer?
For years now I have put together a seal leak device that can be used on many boatwater pumps.
It consist of a PVC pipe end cap pick out to closely fit around the body of the pump under the weep hole/slot in the pump body. Sometimes it takes a little heating with a torch and molding the softened plastic to the shape I want and a little trimming to make it fit snugly and straddle the pump from side to side.
Then two SS #8 machine screws are threaded into the bottom about 3/4" apart. Put an additional weep hole in the bottom about 1/8" diameter.
The assembly is held onto the pump with either or both hose clamps or plastic zippy ties.
Run a ground wire from engine block to one machine screw, and another to the other machine screw to the Ground on a warning buzzer. Fused hot to the buzzer as normal. Then when the lip seal starts to drip the rising water completes the contact between the screws and the buzzer goes off. When the engine is stopped the water drains out and buzzing stops. Works much like an over heat buzzer - but it tells you before the actual overheating.
Normally a leaking seal will not be known about because the pump continues to function normally and only fails when the bearings have had enough water exposure and seized - and major pump failure is found. Also unless the skipper does a close exam before starting the engines no drip will be seen on a stopped engine. And initial leaks are sometimes slow drips while running.
......... Do I need special tools for getting them out?
Small hammer and pieces of wood for support and to use as a drift/dolly.
More importantly - when refitting the bearings, never ever ever hammer the inside race. Ideally the bearings should be pressed into place but can be gently tapped into place using a soft drift when in the field.
A large socket with an OD slightly smaller than the OD of the outer race is useful tool along with a large vise. Used together, they become a "field press"
Originally Posted by blubaju
All suggestions correct, bearings, o-rings, lipseals, all standard industrial parts, lipseals & bearings always go together, just look for a bearing company
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Re: Help with Yanmar 3YM30AE raw water pump
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?
Not an emergency repair at all... common practice in salt water pumps. Does not materially affect the life of t he seal. I've not done Yanmar pumps, but for the typical Johnson pumps we've encountered, the seals cost 2-3 dollars, even here in Oz, where everything is dearer than the USA. And the bearings were not much more, to my surprise... 6-8 bucks each. Dunno how even the Chinese can do them for that!
Jim and Ann s/v Insatiable II lying Port Cygnet again, freezing our bums off.
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.
Thanks for the info. Iíll keep an eye on it. Iíve heard itís a good engine, and it easily pushed our boat to over 8 knots during our sea trial. (38í boat).
I have some notes on the rebuilding of my 3YM30 raw water pump that I will gladly share with the forum. I will add more images to a second post if necessary. I hope they post correctly.
Amazing tutorial Doublewide! Now I feel confident I can do a rebuild myself. Thank you so much for sharing your knowledge!
Only problem is that were I am the cheapest ball bearings that I found cost about USD50.00 each. I would need two + the lip seal, so I would end up spending approx USD150.00. I also found the entire pump at USD220.00.
I don't understand the logic in Yanmar pricing...
Thank you also for sharing your PDFs! I just saw that you can get both ball bearing from Amazon for USD12.00! Fantastic!