Is this LU Oil good

[zippy83]

Hello all,

I have actually drained this LU oil a few days ago and left it in the oil pan. I have not really paid too much attention to it untill today.
Please see picture below:

The oil that came out first was dark green but the last little that came out was a little different color.

Can I assume there is something wrong or nothing?

 

[racerone]

What motor ?--------------How many ounces of oil drained out ?

 

[zippy83]

1974 mercury thunderbolt 50hp
Not more then 12oz fit in there according to the manual

 

[zippy83]

No Title

This is the last drop I cleaned up from the LU

 

[Grub54891]

Looks to be contaminated. Pressure check the unit just to be shure.

 

[zippy83]

Well... I had a similar problem last year. The oil was more contaminated, took it to the mechanic and he replaced some seals along with the water pump.

As for the pressure tester how should I go about making one? I have a small 100 psi air compressor. What else do I need?

Also do I need to take apart the LU?

And one more thing.. Can I leave the lower unit screws off for a few days so that everything drains out?

 

[roscoe]

Well, you only need 4-5 psi to pressure test a lu.
Any more than that, and you risk pushing a seal out.

Lube doesn't look water contaminated to me.
Looks dirty/old.

Yes you can let it drain for a few days.
Can also flush it out with lube and let it drain afterward.

 

[zippy83]

if it needs only 4-5 psi what would be the best way of testing this then?

I also thought that the lube looks dirty but the fist 85% of the lube that came out first looked dark dark green, and the last 15% looks grey, that was my only concern. If there is a leak somewhere it must be very very tiny.

 

[racerone]

I use a bicycle pump and a homemade adapter for the 3/8"-nc thread.--------No risk of injury or damage to the lower unit at 5 PSI

 

[foodfisher]

For fun, wrap a stringed magnet in plastic and drop it in the oil. See what collects.

 

[64osby]

Oil looks old and dirty to me. Oil with water looks more like coffee with cream in it in my experience.

 

[zippy83]

Oil looks old and dirty to me. Oil with water looks more like coffee with cream in it in my experience.

That was my experience last year all of it came out like coffee with a lot of milk in it. The only reason I asked here is because the first 80% of the oil came out dark green and the last 15% or so came out gray.

 

[zippy83]

No Title

If I was to pressure test this, here is what I came up with. what do you guys think?

I also recall after I drained the oil the first time and put the screws back in, yesterday after loosening the upper screw I heard the air being released. I don't know if that might be a good indication or not.

 

[Grub54891]

Your setup should work-as long as the threaded part don't leak at the threads.

 

[ondarvr]

That was my experience last year all of it came out like coffee with a lot of milk in it. The only reason I asked here is because the first 80% of the oil came out dark green and the last 15% or so came out gray.

When oil sits around the junk in it starts to separate, your oil looks perfectly normal, changing color as it comes out means little unless you start to see water or metal chunks. That dark junk is normally floating around suspended until you leave it sit.

 

[zippy83]

Just did a pressure test and I don't seem to lose any PSI. Pumped it up to about 5 PSI and left it there for 4 - 5 min and the gauge didn't move

 

[JimS123]

If there is water in the oil the water comes out first. The gunk that comes out last is the dirt floating on top. Looks like it hadn't been run in a while because it settled so much. If 80% was still green the oil probably didn't need to be changed. Fillerup and forgetaboutit.

 

[zippy83]

Sounds good. At least I learned how to do the pressure test on this unit.
Thanks
Zipp

 

[Faztbullet]

You only tested it 1/2 way you also need to vacuum test it. It can pass a pressure test but fail a vacuum test.

 

[Sea Rider]

If wanting lube to be much cleaner you should change it every 100-150 worked hours on recreative boats....Looks just bit contaminated to me, at least water free, worry if finding metal fillings on drained oil.

Happy Boating