pressure in lower unit (water) Johnson

[flatsman]

Ok, fellows, how can ya get water in the lower unit and have pressure in the lower unit when the motor has been shut down for 16 + hours ? Is it the shift shaft seal the prop shaft seal or the drive shaft seal. The motor is a 1996 johnson ocean runner.

 

[alcan]

Re: pressure in lower unit (water) Johnson

Hi Flatsman<br /> Magic! No seriously, it is entirely possible. Quite often seal will only leak in one direction. They may leak out but not in. This is why we test lower unit for both presure and vacuume. Your L/U could be leaking at several points. The only way to tell is do the tests.

 

[P.V.]

Re: pressure in lower unit (water) Johnson

In order to drain and pressure check the gearcase, you have to remove at least one drain plug. Is it possible that THAT drain plug/gasket was the culprit?? What pressure are you checking with?? I usually check at a low pressure (4 or 5 psi) and then at a higher pressure (14/15 psi).

 

[flatsman]

Re: pressure in lower unit (water) Johnson

ok , we pulled the unit down and the drive shaft seal was leaking (worn badly ) also replaced the shift shaft seal. By the way how long should the unit hold a vaccum ?

 

[alcan]

Re: pressure in lower unit (water) Johnson

Flatsman<br /> There isn't a set time limit. If it holds it holds. If it doesn't, it leaks and still needs repair. The unit should hold at 15 lbs psi and 15hg vaccume. The test gauges will reed solid.