Johnson 150 gearcase pressure testing

[kjdunne]

2000 J150, I replaced water pump as regular maintenance and all seals while I had the unit off. The factory manual says to pressure test to 5 lbs, then 16-18 lbs. Vacuum test to 15 in.
For how long should these values hold? The manual does not say.
Thanks, Kal

 

[Crosbyman]

if it isn'T sealing ypou will see soon enough...go 10 minutes and see what happens !

Google Search

 

[Chris1956]

Gee, what seals did you replace? Unlike Merc's driveshaft seals, Johnnyrude gearcase seals have nothing to do with the waterpump.

 

[kjdunne]

Thanks Crosbyman.
Chris, sorry for not not being more specific. I replaced all gearbox seals, driveshaft seals under the water pump, shift rod o rings, prop shaft seals, prop shaft housing (bearing carrier) o rings, drain / fill plugs nylon washers.

 

[racerone]

If seals are 25 years old, it was good practice to replace them.

 

[kjdunne]

Testing results as follows:
Pressure test #1
Start 18 psi
5 mins 16 psi
10 mins 16 psi
15 mins 15.5 psi
20 mins 15 psi

Pressure test #2
Start 18 psi
5 mins 17 psi
10 mins 16 psi
15 mins 16 psi
20 mins 15 psi

Vacuum test #1
Start 15 in/hg
5 min 15 in/hg
10 mins 15 in/hg
15 mins 15 in/hg
20 mins 15 in/hg

Vacuum test #2
Exact same results as test #1

I'm calling it good, refilled with marine gear lube.
Will get it in the water and run it later this week and check gear lube for any water itrusion.

Wish me luck!
Kal