Df150 lower unit seals

[snapper30]

Does anyone know of a place to buy a cheap pressure tester that can be used to check the seals on the lower unit?

I plan on buying the all the seals for the lower unit but I'm not sure what all I need. Could someone let me know what seals I will be needing?

1. Prop seal?
2. Water pump kit?
3. Is there an upper shaft seal?

I also see a gear case sealing kit available from suzuki but it doesn't specify what's in it.
2009 df150

[Solarman]

df150, lower unit seals

Most lower units have a total of 8 seals. It will have 2 seals for each shaft location. An O'ring seal for the casing and shaft seal for the prop shaft. Then an O'ring seal for the upper bearing case (under the water pump assy) and shaft seal for the drive shaft. Another O'ring seal for the outside and inside of the shift rod casing. Then 2 seals for the oil drain & fill screws.
There are other seals and grommets for the water pump case & tubing, and additional grommets & seals for exhaust, and sub-water pickup tubing.
They should be able to tell you what seals are included in the kit.

Why do you need a pressure tester? Basically, either you are getting water into the oil (it will look milky grayish/ brownish color, or you will have oil leaking out. And generally if oil leaks out, water will usually get in, causing the milky color.
Is your motor still under a warranty?
Good luck. Let us know.

[snapper30]

Yes i had quite of bit of water get into my lower unit. Oil came out very white. Thought the original problem was a double gasket on the filler plug which cause a bad seal and oil to leak out and water in. I changed my oil and ran for another 3 days. When I went to.change again I was expecting some water in oil but instead it was lots of white again. So I refilled with fresh and ran for another 4 days expecting it to be white but this time.it was.only a little water mixed with oil.

Long story short I wanted to hook up a pressure tester to see if I could tell if I had a bad seal or if it was just residual water from bad screw gasket. I bought the engine with 180 hours on it and it now has 440 just since May. So this engine gets a work out.

[artdf175]

One of the seals that is notorious is at the end of the shaft behind the prop
Fishing line is the usual culprit- cuts up this seal quickly
I had one problem after the mechanic replaced a bent prop shaft
The way he found the leak was to apply a air pressure hose to the fill hole and look for oil/air to get by the seals
I know with the fill and drain screws it is recommended to replace washers at oil changes
Art

[snapper30]

One of the seals that is notorious is at the end of the shaft behind the prop
Fishing line is the usual culprit- cuts up this seal quickly
I had one problem after the mechanic replaced a bent prop shaft
The way he found the leak was to apply a air pressure hose to the fill hole and look for oil/air to get by the seals
I know with the fill and drain screws it is recommended to replace washers at oil changes
Art

Will oil usually be able to be seen if leaking out prop seal? Also does anyone know of a pressure tester to use with suzuki?

[Solarman]

df150, lower unit oil seal problem

There should be some signs of oil leaking at the prop seal if leaking. If it looks clean and no oil residue, then it probably is one of your upper seals leaking.
If you have water getting in after 3 or 4 days, the leak is considerable.
As you run your motor, the lower unit oil gets hot, cooled by the transfer of heat to the case in the water. But the oil expands when heated, building pressure. If the pressure escapes when heated, then you stop and anchor for an hour, the oil cools and creates a vacuum. Water gets pulled in
It's not hard to replace the upper seals on drive shaft, and shift rod, once the lower unit is removed. Probably easier than pressure testing.
The prop seal can be replaced with lower unit still on motor, but this seal case may require a puller to extract.
Your manual can be very helpful if you decide to do it yourself.
Good luck, and let us know how you're doing.

[MauiBoatdoc]

Have you purchased a tester yet?

Most auto part stores have a radiator pressure tester that you can modify to test any lower unit.