Pressure/vacuum check question Top or Bottom-gctid381746

[Guest]

Boats been running like a champ with the new engine. Water is in the 280 drive now. I ordered a tester. Is it best to pressure check from the top (Dip Stick) or bottom ? both times after replacing oil and running it. When I took the dip stick out it made a "POP" sound? Reason I ask about the bottom when I took the lower unit screw out there was no "O" ring or gasket around the screw. Just wondering if its sucking in water there ?

Thanks

Roger

[2850Bounty]

Drain the drive oil before doing a pressure leak-down test. The Vacuum leak-down test doesn't care.

Spin the prop shaft and rotate the eccentric piston while doing either test.

I use the dip stick port for the pump and gauge.... new O-ring at the drain plug.

You must replace the dip stick and drain plug O-rings with new becuase these are not to used a second time.

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[Guest]

2850Bounty wrote:
Drain the drive oil before doing a pressure leak-down test. The Vacuum leak-down test doesn't care.

Spin the prop shaft and rotate the eccentric piston while doing either test.

I use the dip stick port for the pump and gauge.... new O-ring at the drain plug.

You must replace the dip stick and drain plug O-rings with new becuase these are not to used a second time.

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So every time I check the outdrive oil (Top and Bottom) I should replace the O rings ? Anybody have a good source for O rings for the 280 ? I checked Volvo Penta web site. They wanted $46 to ship a $2 O ring to Alaska Gotta love people who think Alaska is a different country

[2850Bounty]

There are only a few of these standard O-rings (sold at hardaware stores) that will work. The drain and dip stick O-ring are one of these.

Try looking at the #2-110 in their O-ring supply. About 29 cents each.... buy several!

If you were to install a new one, and were to remove/replace the drain plug or the dip stick within a few days only, they can usually be re-used.

Any longer than that, I'd not re-use one. (the material takes a set)

Where is Alaska, anyway?

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