Water in lower unit

[KCShorty]

Like the title states, I am getting some water in my lower unit. I have been trying to change the fluid more often since I know that it leaks a little. I have read on here that you can pressure test the lower unit to see where the water is getting in. How exactly is this done? I have an air compressor. Do I just put the very bottom of the lower unit in a bucket of water and pump pressurized air into the upper gear oil plug?

 

[wilde1j]

Re: Water in lower unit

Test leaking lower unit ? pressure or vacuum (both recommended)

1. Drain gear oil
2. Pressurize (or apply max vacuum possible) to no more than 15 psig with air (see OEM shop manual for max for your motor)
3. Submerge in water, look for bubbles
4. Possibilities
a. Drive shaft seal
b. Prop shaft seals
c. Shift rod seal
d. Cracked casting
e. Drain/fill screws/seals
5. Repair as needed

For V4 and V6 lower units, should hold some pressure or vacuum for at least 45 minutes.

If a seal(s) is found to be leaking, inspect the shaft (prop or drive) carefully for grooving. If there is any, make sure the new seal(s) do not seat in the same place as the groove.

 

[KCShorty]

Re: Water in lower unit

Test leaking lower unit ? pressure or vacuum (both recommended)

1. Drain gear oil
2. Pressurize (or apply max vacuum possible) to no more than 15 psig with air (see OEM shop manual for max for your motor)
3. Submerge in water, look for bubbles
4. Possibilities
a. Drive shaft seal
b. Prop shaft seals
c. Shift rod seal
d. Cracked casting
e. Drain/fill screws/seals
5. Repair as needed

For V4 and V6 lower units, should hold some pressure or vacuum for at least 45 minutes.

If a seal(s) is found to be leaking, inspect the shaft (prop or drive) carefully for grooving. If there is any, make sure the new seal(s) do not seat in the same place as the groove.

Thank you for the response. So I can turn my compressor output to say 10lbs. Take the blower attachment and stick it in the upper gear oil hole and pump it full of air. Once it's got air in it, submerge the lower unit in water while holding the air nozzle in the lower unit? Sounds kind of awkward...is there a better way?

 

[wilde1j]

Re: Water in lower unit

I made an adapter years ago with a Schrader valve, a gauge and a fitting that screws into the drain or fill hole. You need to check again after repair to be sure it's OK ... I wouldn't want to hold anything for 45 minutes.

Can't say 10 psig is OK, BC you haven't said what motor.

 

[KCShorty]

Re: Water in lower unit

I made an adapter years ago with a Schrader valve, a gauge and a fitting that screws into the drain or fill hole. You need to check again after repair to be sure it's OK ... I wouldn't want to hold anything for 45 minutes.

Can't say 10 psig is OK, BC you haven't said what motor.

Sorry, It's a 1982 Johnson 25hp tiller.

 

[wilde1j]

Re: Water in lower unit

Don't have a book for that motor. Maybe someone can post the test pressure for your motor.