1971 MERCURY 500 (50HP) Lower Unit

[aff]

I am getting water in the lower unit. I changed the propeller shaft oil seal and the O ring. But still getting water, as the oil is white after use. It is better but still water gets in. Where can I purchase a cheap pressure tester? I think there is anouther oil seal by the water pump, is that a common place for water leak? Any sugestion welcome.<br />Andy

 

[petryshyn]

Re: 1971 MERCURY 500 (50HP) Lower Unit

>Lip seal under pump impellar<br />>shifter shaft seal<br />>upper housing gaskets

 

[tmcalavy]

Re: 1971 MERCURY 500 (50HP) Lower Unit

My 73 Merc 500 lower was taking water due to a bad shift shaft seal...rubber O-ring. The mech pressurized the unit by pumping air into it with a bike pump equipped with a pressure gauge. Then he sprayed soapy water around the seal areas, air bubbles from under the shift shaft, so he replaced that seal. His pressurizer looked simple enough to make. All you need is a fitting that will screw into the drain or vent hole and a guage to screw into the other hole, plus soapy water. Good luck.

 

[aff]

Re: 1971 MERCURY 500 (50HP) Lower Unit

Thanks, I will change those as well. <br />Andy