changed water pump now i have water in lower unit

hello
i have a merc 1994 40hp ser#0g024796 modle# 40elpt 2 stroke i replaced the water pump lower & upper last week (i used the repair manual) done great in yard on the muffs no water in lower unit so i carried to river came home checked lower unit (3rd time since new pump) water was in oil so i pulled lower unit again i noticed a little raised notch at the back just in front of the single stud where the water pump goes i thought it was trash tried to scrap off but its built into the lower unit (didnt take long to figure that out) i only used one gasket where the base meets the lower unit are you supposed to use 2? i change the lower unit oil 2-3 a season never had water in oil till now i also noticed when i dropped lower unit there was some water coming from the water pump base i bought another water pump from i-boat just want to make sure i get it right this time 50 a pop adds up i have some pics if i can get to upoad

thanks

Re: changed water pump now i have water in lower unit

One base gasket should be fine. Did you use the correct oring on the pump base? Inspect the driveshaft seal in the pumpbase for damage. Inspect the driveshaft for damage as well.

Re: changed water pump now i have water in lower unit

Chris1956 said:

Did you use the correct oring on the pump base?

Click to expand...

I used the larger o-ring (thicker) i thought the tighter the seal the better, but it does fit the base better than the smaller one, far as the drive shaft it all looks good no nicks,gouges, or groves, should i have use some sealant where the base of the water pump meets the lower unit, i thought it (raised piece) was there for a reason thats why i did not use any, i did check the oil seal on the base looks good also, i have another new pump

thanks

Re: changed water pump now i have water in lower unit

You shouldn't need any sealant on the waterpump base gasket. You did use a gasket, right?


It sounds like you need to pressure test the gearcase to find the leak.

Re: changed water pump now i have water in lower unit

i used the gasket, i put it together just like it was when i pulled the old one, and i use the repair manual, also i took pics as i removed the old one, its been apart all week i'm going try the new pump the oil seal on this is just a little tighter on the driveshaft i don't know why same part #s, i think i will put the lower unit back together and do a pressure test before i run it to make sure its not leaking again