Dhadley or other gurues help 120 V4 lower unit

[MarkHPCA]

I am suspecting that the seals are not good on my lower unit. I changed the oil in the spring and after about 3 hours this is what it looked like (shot glass) I left it in the glass for two days but nothing seperated, maybe it is just airated?<br /><br /> <br /><br />I did a pressure test and it holds 15 PSI for over one hour and will hold 11 in hg for over an hour (iI can't suck more than 11 in hg for the vacumme test) what do you guys think? Is this water or air bubbles.

 

[Solittle]

Re: Dhadley or other gurues help 120 V4 lower unit

I'm betting on water and if your pressure & vacume tests show no seal leaking I'd bet on the nylon gaskets or o rings on the fill & drain plug (depending on which you have). They need to be replaced every time you change the oil.

 

[MarkHPCA]

Re: Dhadley or other gurues help 120 V4 lower unit

That's what I thought at first so I put in new ones and re-filled. Same thing after a couple of hours. I would have thought that water/oil would have seperated after several days in the shot glass but it stayed just the same.

 

[MarkHPCA]

Re: Dhadley or other gurues help 120 V4 lower unit

Anyone else some ideas?

 

[wilde1j]

Re: Dhadley or other gurues help 120 V4 lower unit

~

 

[wilde1j]

Re: Dhadley or other gurues help 120 V4 lower unit

Are you testing with the LU gear oil drained? The oil will mask test results otherwise. You clearly have some water in the gear oil.<br /><br />Try the vacuum test with a much higher vacuum. 11" Hg vac isn't much (30" hg vac~ -15 psig). Borrow a brake bleeder to get a higher vacuum. There's a limited number of places for water to enter ... prop shaft seals, drive shaft seal, shift rod seal or a crack in the LU housing, plus the fill, drain screw seals.<br /><br />Good luck!

 

[MarkHPCA]

Re: Dhadley or other gurues help 120 V4 lower unit

I drained the oil but there is always some left. Should I flush it with something?

 

[MarkHPCA]

Re: Dhadley or other gurues help 120 V4 lower unit

Did a pressure test again tonite. Found it would only go to 12 PSI, any higher and it would drop back to 12 PSI. Pulled the LU and found the driveshaft seals are bad. Guess I will be getting new ones. Rats ! I only replaced them a year ago but I did take the water pump off this spring, maybe that did something. Thanks for the help guys.