Lower Unit

[GMCAMARO]

Last week when I tilted my motor out of the water, I noticed something dripping, I checked it and it was greasy. I changed the lower unit oil yesterday and noticed some small amounts of water in the lower unit oil. The drip was about 2 inches below the exhaust port. There appears to be a breather hole slightly above the lower unit. Any thoughts? The motor is a 15HP 56' Evinrude.

 

[Joe Reeves]

Re: Lower Unit

To check for lower unit leakage, drain the unit, install one drain or level screw, then apply 7 to 12 pounds of pressuried air to the unit via the open screw hole. Now, look and listen for an existing leakage point.

 

[rickdb1boat]

Re: Lower Unit

In addition to what Joe said, shooting soapy water from a spray bottle everywhere on the lower unit will make a leak show up quick when it's under pressure...

 

[GMCAMARO]

Re: Lower Unit

To check for lower unit leakage, drain the unit, install one drain or level screw, then apply 7 to 12 pounds of pressuried air to the unit via the open screw hole. Now, look and listen for an existing leakage point.<br /><br /><br />What where you using to get the air in and keep it in?

 

[kd6nem]

Re: Lower Unit

Make a gizmo with a barbed pipe thread fitting, a tee, a pressure gauge (0-30psi works well), and some tubing and tie wraps or tiny hose clamps. Threaded fitting goes into the open hole, gauge attaches to the tee. Hook the remaining open end of the tubing to a bicycle pump. Bike pump is easier to control the pressure. A valve between the pump and the rest of the setup is nice, though vise grips might work if you can't come up with something better. Medium sized metal hemostats are better than the vise grips if you can find them. I like to slip some tubing over the jaws to keep them from chewing up the tubing to be clamped if the jaws are not the smooth kind. The cheap plastic tubing hemostat clamps I do not trust for that much pressure, especially with thicker tubing. Make sure the test rig does not itself leak before testing the lower unit.