Mercury 2002 15 HP 2 Stroke Water in L/U

[w2much]

This motor pumps water well.When I went to replace the lower unit lubricant water was visible. I took the lower unit off and noticed that all around the water pump was what appeared to be lower unit grease kind of jellified with water into a creamy white mud. I was going to put in a new impeller . Looking at the parts list I am a bit confused as I see a water pump kit and also a seal kit offered by mercury. Does the water pump kit have the seals I will need or should I just purchase an impeller and the seal kit?

 

[Texasmark]

Just below the water pump are a couple of drive shaft seals that seal the lower unit oil in and the surrounding water out. There is no oil associated with the operation of the water pump....water acts as the lubricant and while we are at it, if out of the water on the garden hose and adapter (muffs) water comes on first then operate the engine and off after the engine is shut off.

Unless you are operating under horrible circumstances, I'd be surprised that you were already wearing out your drive shaft seals. What did the oil in your lower unit look like when you drained it? Was it chocolate colored, or marbled with yellow swirls, or yellow or plain water came out first when you pulled the drain plug (engine in a powerhead up, vertical position)? Any of those symptoms indicate that you have a leak and then yes, possibly the seals are the cause.

 

[w2much]

Texas, Thank you for your response. When I opened the fill and drain plug on the lower unit straight water can out then oil(gear lube). Previously mentioned a bunch of coagulated grease all around the water pump. Certainly water in the lower unit. Original question- Does the water pump kit contain the seals I will need or do I need the seal kit. They are two different kits.

 

[Texasmark]

Texas, Thank you for your response. When I opened the fill and drain plug on the lower unit straight water can out then oil(gear lube). Previously mentioned a bunch of coagulated grease all around the water pump. Certainly water in the lower unit. Original question- Does the water pump kit contain the seals I will need or do I need the seal kit. They are two different kits.

Nope. Only parts are the ones associated with the pump and how many parts depends on what level of the pump you order. You can order the impeller or the whole pump assembly with all gaskets and wear plate, housing and all. These rubber seals will show up on the lower unit parts breakdown just as the pump parts will show up. There are 2 back to back.....reason is one blocks oil from going out and the other in the opposite direction blocks water from entering the LU.....same arrangement on the prop shaft right in front of the prop's thrust washer....in the R gear Bearing Carrier Assembly....another place to have a leak, and lastly (without a cracked casting) would be the shift rod seals at the front, top of the LU, and the seals on your drain and vent screws.

 

[w2much]

Texasmark Thank you.Went ahead and ordered the seal kit and an impeller. I see some of the last l/u grease coming out , looks to have rust in it.

 

[Texasmark]

Get some ATF and set the engine vertical like when normal filling of lower unit. Fill the LU with it like you would normally fill it with the regular LU oil. Run the engine on muffs at idle for a few minutes going through the gears getting everything oiled up.

Drain that oil and let the engine sit upright overnight with the drain and vent plugs removed. Then do a pressure test on the LU and you can find out how by looking for "How to pressure test an outboard motor lower unit" on the Google search engine. That will tell you if those seals are leaking and if you have any other leaks.

When you get all the repairs done, fill with new LU oil. WM has it in Pennzoil or Merc brands. I like to use their premium oil in my higher hp engines. On your engine it really doesn't matter all that much since the mechanical pressures aren't all that high.