Oil Leak Where Actuator Mounts To Transom

[Stray Cat]

Tabman

I have a 2006 Sea Ray 300DA with the classic trim tab system. I believe the actuator used is A1101A.

A couple of weeks ago I cycle tested the both tabs to make sure the actuators were working properly prior to spring launch. I did not perform the 24 hr leak down test, I just tested 2 cylces of extend and retract.

Today while finishing up spring prep, I noted a film of oil leaked from the top of the actuator (where the 3 screws mount the top of the actuator to the transom) down the transom.

I presume if it was a leaky actuator, oil would be found on the actuator's rod end. Is it possible the pipe nipple could be leaking from the threads and running down the transom? How is the top of the actuator sealed against the hull?

Thanks for your support!

 

[fwebster]

There is about a 2" pipe nipple screwed into the back of the actuator, it passes thru the transom and is connected to the hydraulic tubing inside the boat. The actuator base is screwed to the transom usually with a bedding compound under it. Your leak is either a broken actuator base (unlikely) or at the threaded hole where the pipe nipple attaches.

 

[Tabman]

Frank is on target with his reply.

It is likely where the 3" pipe nipple screws into the upper hinge of the actuator. The pressure is forcing the fluid out past the sealant between the upper hinge and the transom.

Tightening the pipe nipple usually will not work as it can strip the threads or block the fluid hole.

Replacing the upper hinge and pipe nipple is the best fix. We can send you new ones, at no charge. But SeaRay uses some nonstandard actuators, so to get the correct upper hinge I need to know if there is about 1" of piston shaft still showing when the Tabs are all the way up, or if the lower hinge almost touches the cylinder body when they are retracted.

Let me know and send me your name and address in a PM and we can mail the parts to you.

Tom
Bennett Marine

 

[Stray Cat]

Frank / Tom, thanks for the explanations and diagram.

 

[Stray Cat]

Tom - I received the the parts, completed the repair, and it pressure tested ok. As I replaced the o-ring on the piston, I was curious how the rod is sealed on the water side of the actuator. Thanks again for the support!

 

[Tabman]

Jeff,

Good to hear the repairs worked!

The bottom of the cylinder body is open and water is allowed to enter it. This is a very important feature of our actuators. The piston O-ring makes the seal, not where the shaft exits the cylinder body. This way if a barnacle or other growth attaches to the shaft it will not cut the seal. This way the actuators can be left in the down position without worry.

Tom
Bennett Marine