Yanmar 3gm30 Water Pump

[Jacana]

Need to find the correct water pump new pump is down 40% on old pump looks identical must have cold and warm water options guess they sold me cold water pump.Thanks geoff.

[Chief Engineer]

I don't quite follow your post. is the the freshwater or raw water pump

[Jacana]

water pump">Raw water pump.Had a leaking pump bought a new one $670.00 from yanmar had trouble ever since with overheating pulled all the system apart bit by bit no blockage anywhere put my old pump that I had reconditioned to keep as a spare back in and it pumps almost double the amount of water through.Now yanmar are trying to figure whats up as the number on the pump plate is identical.My thoughts are there must be a cold water operating pump and a warm water operating pump to cater for the different climates to keep engine at correct operating temperature so am trying to get some part nos.

[never monday]

in the US market there were two pumps for the GM series. One for raw water cooled, and one for closed cooled. The pumps are obviously different sizes when next to each other.

[Jacana]

Yeah those are different sizes however these are identical in size and same backing plate no.mine have the outlet/inlet hose coming straight out the smaller size pump comes out at about 30 degrees.Someone at the workshop said maybe the cam was different inside the pump that forces the impeller to squeeze closed more therefore sucking water in faster.Any ideas.

[never monday]

Originally Posted by Jacana

Yeah those are different sizes however these are identical in size and same backing plate no.mine have the outlet/inlet hose coming straight out the smaller size pump comes out at about 30 degrees.Someone at the workshop said maybe the cam was different inside the pump that forces the impeller to squeeze closed more therefore sucking water in faster.Any ideas.

take them apart and have a look inside

[Jacana]

Peak season ,do charters daily, was hoping to get the correct info. to give to yanmar without removing the water pump will wait to bookings drop off as I dont want to lose money if someone knows of the 2 different water pumps part numbers I can get the replacement pump from yanmar without losing my charter customers.

[Inlet Marine Services]

Which model is this? 3GM30 or 3GM30B or 3GM30F. The parts CD I have show a fresh water cooled and a raw water cooled pump. The fresh water cooled pump is larger, the impeller is much bigger then the raw water cooled pump. Raw water cooled motor Part # 128270-42000 changed to 128270-42001 changed to 728270-42002
Fresh water cooled motor Part# 121575-42000 changed to 721575-42701
I hope this helps

[gonesail]

maybe someone can help .. i am in process of replacing the water seal on this 3GM pump (721575-42701) .. have seal and washer in hand. inside seal is circular spring. looks like seal goes into pump first with spring facing towards rear of pump where bearings are .. then rubber washer .. then the shaft. i can't find any diagrams online. pictures worth a thousand words here i know. cheers.

[Vasco]

Yanmar parts can be tricky. I replaced a 3GM30F (hydrolock, ruined engine) with a 3GM30F. Same engine, about a few years newer. Kept all my old spares. Sailed for a couple of years and needed a new impeller. Pulled out my spare ..... not the same!!! Apparently (and this is what the dealer told me) this was in 2003 and Yanmar sensing a downturn did not import a lot of diesels to North America. The replacement I got was a European model and took a different impeller. I'd been sailing for years thinking I had one and bingo I really didn't have one. Lucky I was in Toronto when I needed the new one and it wasn't a problem getting it. So what they say about installing the spares and keeping the originals as spares is a good idea. At least you will have the comfort of knowing you've got the right spare. Now all I need is for someone to tell me that the oil cooler in a 4JH3E needs a zinc! Apparently some do and most don't. Spent a week getting to the bottom of that one. Yanmar parts can drive you crazy.

[ShipShape]

Call Bay Shore Marine and talk to Chuck - he will help you solve your problem and ship you the parts you need. None of the Yanmar territorial crap with Bay Shore, and they ship UPS daily. 410-263-8370

Web address: Bay Shore Marine Engines - Annapolis, Maryland - Welcome


PS Tell him Priscilla says "hi" and he will expidite your order.

[gonesail]

FYI Chuck no longer at Bay Shore. but the word is the spring will face towards whatever fluid is being sealed .. in this case it will face the impeller and the water.

[ShipShape]

Chuck is no longer at Bayshore??? That is too bad, he was with them for a long time and was super helpful. Who do we talk to now?

[Inlet Marine Services]

I will try to answer a few question, There is no zincs on a 4JH3E, on a the seal the open end always goes toward the fluid. Yanmar sell a different pump for a 3gm30f, the european looks and operates the same as the US pump but the cam is built in and the impeller is a Johnson 810b which is half the price of a yanmar impeller or the same impeller that the new 3YM30. The pump is about $100.00 cheaper also.

[Chief Engineer]

Chuck is now with Hinckley in Oxford Maryland

Klaus is the go to guy at Bayshore