05 Yamaha 150 leaking trim cylinders

T

Trophy20002

Member
Joined
Oct 24, 2023
Messages
21
Reaction score
19
Points
3
Age
47
Hello all, I realize this isn't a Yamaha forum, but most Gradys I see have them and I'm hoping there's someone more experienced with these systems. Both trim units were resealed just before I bought the boat. They're obviously new, however the one trim unit the two trim seals have oil constantly weeping, not a lot, but always wet. From the diagrams I have seen I would assume there wouldn't really be any or very little oil on the rod side of these cylinders, I may be wrong about that. That being said my question is, if the system had been over filled, could this be a cause? That outboard is slower trimming up than the port side as well. I will have to source the cylinder tool and pull it apart to check the internals.

TIA
 
S

seasick

Well-Known Member
Joined
Aug 19, 2008
Messages
9,145
Reaction score
1,312
Points
113
Location
NYC
Depending on your motor model, the trim caps may use either one or two seals per cylinder. On my older motor, the cylinders had two seals but more importantly one of them only works correctly if it is installed facing the correct direction. It has a lip and a groove that must face the right direction. The service manual shows which way but you van figure it out if you install it so that the oil inside the cylinder forces the seal to expand.
All that aside, if your rams have damage, either corrosion, pitting or scratches, new seals may not help. In those cases the rams have to be replaced.

Take a look at a youtube video on yhr Born Again Boating channel that was posted last week. It shows the whole process.

Also, it is just about impossible to overfill the unit. Under filling is easy but the design of the reservoir causes the fluid to overflow out of the fill hole when filling reaches the correct level (with rams extended of course)
 
  • Like
Reactions: PointedRose
You must log in or register to reply here.