1976 johnson 85hp

[tcount]

i replaced the impeller in the water pump, while i have it tore down is there anything else that i need to look for or at.<br />is there any way to flush it out while it is down

 

[ezeke]

Re: 1976 johnson 85hp

Exhaust seal OK?<br /><br />Good time to do a pressure test if you have any doubts. <br /><br />Clean and lube the shift rod where it enters the gear case. <br /><br />Check the prop shaft for fishing line. Grease the prop shaft splines.<br /><br />Look for corrosion on the bolt holes and clean if there.<br /><br />If you are going to use lower unit anti-fouling paint this would be a good time. Just be sure you have the right stuff.

 

[tcount]

Re: 1976 johnson 85hp

exhaust seal good, no line on prop.<br />how to pressure test, i dont know

 

[ezeke]

Re: 1976 johnson 85hp

Use a hand pump with a gauge.Add pressure through one of the oil inlets to 3 to 6 psi. If the pressure drops, submerge the unit so that you can find the leak by the bubbles. <br /><br />The service manual says increase the pressure to 16 to 18 psi. I think 10 or 12 psi is plenty. The gear case should hold the pressure for 15 minutes or more.<br /><br />If you put too much pressure you can blow a seal, so don't run the test with oil in the gearcase.

 

[OBJ]

Re: 1976 johnson 85hp

Pressure testing is done by draining the gear lube and pressurizing the gear case with air. Some will put the gear case in water to check for leaks while others have a gage to watch. <br /><br />A vacuum test is also a good idea. Sometimes the outter seal will leak. The seals on your gear case are back to back seals. Inner seal keeping the oil in and the outter seal keeping the water out. So, an outter seal could go bad and let water into the gear case. A pressure test would not find an outter seal....but a vacuum test would. <br /><br />If your gear lube get's milky looking or you have a drain of water when you pull the gear case drain plug, then it would be a good idea while the gear case is off, to get it repaired.