YANMAR 2GM20F water cooling loop

[sxsilver]

So previously I had a hose clamp come off right after where my impeller was. This caused me to get a new hose clamp and also get a new waterlock because it melted. Then found out that something was leaking. At the time I didn't know what it was but turns out the impeller casing is leaking.

I took off the impeller casing and took the impeller out. The impeller only had three of the six arms. I highly highly hope that when the hose came off the pieces dropped down and out but I have no idea and I at least don't see them checking up to the heat exchanger. So how much should I or can I take apart to find these little pieces?

Back to the leaking. So I replaced the impeller and put everything together. Turned the engine on and luckily it all works. However when I turn off the engine the impeller casing is leaking. Is it supposed to be leaking? I'm going to say no but theres two little holes one on each side that look like they are supposed to be there.

I am confused. Please help!

[four winds]

The two holes in the seawater pump are there to let the water escape after a shaft seal failure.

You need new seals. May be one, or may be two seals depending on the pump. The bearings and shaft need to be checked for wear as well.

You can search and find the service manual for your engine as a pdf download. Very good reference if you don't have one.

[sailorchic34]

It's a single double lip seal and easy to replace. You will need cir-clip pliers.

Here is a link to them on amazon https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

You want to find a TC13287 which any bearing supply house will have.

Use a socket to push the new seal in place. The solid rubber back goes toward the impeller. Keep a few spares around for fun.

[boatbod]

Or you could just buy a complete new pump and save yourself time and headaches.

[model 10]

Originally Posted by sailorchic34

Use a socket to push the new seal in place. The solid rubber back goes toward the impeller. Keep a few spares around for fun.

You should elaborate as the spring goes toward the pressure.

[sailorchic34]

Originally Posted by Guy

You should elaborate as the spring goes toward the pressure.

Not in my book it doesn't.

The open/spring side is pointed away from the impeller. For an oil seal, say on an engine the open side faces the inside of the engine, or the pressure side as you said. But for a Johnson water pump">RAW water pump, the open side of the seal faces away from the impeller. Least that's how the original seal was installed on mine.

There are different opinions on exactly which way the seal goes in. In reality it will work in either direction.

[01kiwijohn]

Not really. The spring side goes towards the pressure, ie to keep the water from leaking out of the housing. Also check the condition of the surface of the plate the goes towards the impeller. I

[sxsilver]

Thanks for the replies! I'm going to go get some parts and have some fun after work today to see if I can do it myself....if not a new pump may happen.

[DeepFrz]

And don't forget to put the spring facing in/out.

[sailorchic34]

It appears that the Blonde engineer way is to put the open side out, which is counter to the normal orientation. Not the first time...

My last seal lasted over 500 hours installed my way with a scored shaft. While I can see that putting the spring toward the fluid in a higher pressure system might make it work better. The typical Johnson raw water pump, specially on a 3gm30F is a low Head pump and there just is not that much pressure to worry about. I would say that the seal would not really deflect in either orientation. It is the spring that makes the seal. in either position.

My logic is, not knowing the quality of the spring that placing it away from the salt water might be a good thingy. But that just me and YMMV. As I got over 500 hours from the last seal, I will continue to install the seal my, be it blonde, way. For this dinky seal, I can not see it making a measurable difference in either orientation. The pressures are just too low.

[four winds]

sxsilver, that seal is on the small side. I had no luck at the typical chain auto stores. There was no old school NAPA store within biking distance either.

Worth a try, but better luck may be found at an industrial supply or bearing supply shop.

If you have a Yanmar shop nearby you may be pleasantly surprised the price is not outrageous for this seal, and it is a common part that should be in stock. If not shipping will be twice the price of the part.

If you check prices for a new pump you will most certainly be unpleasantly surprised. 500-600 clams. Shopping around, like Depco in Sarasota FL, May yield better results.

But there is a version of this pump that is less than 300 dollars. It has a non removable cam in the housing. I think this cam rarely needs replacing so that is a choice I would consider if the need presents itself.

To do a total rebuild including shaft (Yanmar only) can be expensive as well.

Hopefully you just need a seal and there is no substantial groove on the shaft where the seal lip rides.

The photo attached is from an old original Yanmar ring binder service manual. The seal is no. 8 in the diagram.

[four winds]

SC, I see you were posting as I typed.

When replacing this seal I considered putting it in "backwards" as you have done. The spring on the old seal had fallen apart and some debri from it surely went through the impeller. Which could score the housing I suppose.

Also considered the o-ring substitution. But in the end did not and installed in the normal way.

[Enchantress]

The typical new price of these pumps is between $500 and $600. Sometimes you see them on eBay rebuilt already for around $400.

When I bought the parts to totally rebuild mine (the only thing I didn't replace was the shaft and the housing) I spent right around $100 with shipping. The rebuild took at most 45 minutes, most of that was getting the old bearings off the shaft. This is a very doable DIY project.

[sailorchic34]

There is one Johnson pump on ebay, rebuilt for $165 ish. The correct pump is a Johnson F4B-902. It's available from several sources.

[sailorchic34]

Originally Posted by four winds

When replacing this seal I considered putting it in "backwards" as you have done. The spring on the old seal had fallen apart and some debri from it surely went through the impeller. Which could score the housing I suppose.

That is exactly the reason I put it in backwards or as I like to call it Blonde-wards. Then the spring is protected from corrosion.