Replaced the water pump on my 3GM30F last winter. Was doing some maintenance today and saw that it's turned green rather quickly. Cause for concern?
Eight month old water pump has changed colors
- Thread starter karellen
- Start date
The green is from corrosion of the bronze pump casing.
My first guess would be that the pump's mechanical seal is starting to fail.
Or maaaaaaaaaaaaybe it's due to the fact that the hose is only single clamped rather than double, as every other raw water hose on your boat should have.
My first guess would be that the pump's mechanical seal is starting to fail.
Or maaaaaaaaaaaaybe it's due to the fact that the hose is only single clamped rather than double, as every other raw water hose on your boat should have.
If it has gone from Shiny to green grunge, then you are seeing moisture on the metal. The question is where is it coming from and how much?
Your pump has a cover and between the cover and the housing is supposed to be a thin gasket. This can sometimes be missing or was damaged during reinstall while changing the impeller.
Or it can be the first sign of bearing failure. The pump has a weep hole. When the bearing seal starts to fail it will let salt water seep out of the weep hole. The pump can be inspected while running. If you see water seeping out, it is time to replace the bearings and seals.
It may be from the hose. The hose may be worn or cracked. You can remove the hose clamp and inspect the hose. It may be fine and then it would be a good time to replace the hose clamp with a stainless steel clamp.
MaineSail has a great "How To" link on hose clamps. Proper Installation Of Double Hose Clamps - Marine How To
Just ideas covering the usual suspects.
Your pump has a cover and between the cover and the housing is supposed to be a thin gasket. This can sometimes be missing or was damaged during reinstall while changing the impeller.
Or it can be the first sign of bearing failure. The pump has a weep hole. When the bearing seal starts to fail it will let salt water seep out of the weep hole. The pump can be inspected while running. If you see water seeping out, it is time to replace the bearings and seals.
It may be from the hose. The hose may be worn or cracked. You can remove the hose clamp and inspect the hose. It may be fine and then it would be a good time to replace the hose clamp with a stainless steel clamp.
MaineSail has a great "How To" link on hose clamps. Proper Installation Of Double Hose Clamps - Marine How To
Just ideas covering the usual suspects.
Looks like corrosion. I had that issue on my 2004 Hunter 386 and discovered a pin-hole leak that had been there prior to purchasing the boat. Replaced the 14 year old pump and removed all corrosion from the motor mounts the leak caused, then painted the motor mounts with anti-corrosion paint.
Some good thoughts here. I would hope an 8 month old water pump wouldn't have bearing problems or leaks, but anything is possible. I'll try the hose and clamps first.
I noticed today that there was some water residue under the large hose below the radiator. It seems possible that it may be running down and dripping onto the water pump. All the hoses are original, so I'm thinking I may take this opportunity to go through and replace all of the water hoses as well as their clamps.
I noticed today that there was some water residue under the large hose below the radiator. It seems possible that it may be running down and dripping onto the water pump. All the hoses are original, so I'm thinking I may take this opportunity to go through and replace all of the water hoses as well as their clamps.
If it leaks at shaft, your belt is probably too tight. Repairing the leak is easy as replacing the oil seal if the small bearings is still good. Check the new oil seal spring. If not SS (test with magnet), then I suggest you replace the metal spring with a suitable size rubber O-ring. When the metal spring gets corroded off the lips of oil seal no longer seal the shaft, hence leaks. Check out 18.15mins and see what I meant by replacing the metal spring of oil seal.
Ken Y
Ken Y