Tilt and trim seals, SX Yami
Last week I resealed my tilt and trim cylinders on my 18 year old 150SX motor. They started to leak at the end of last season (saw an oil sheen on the water at the dock)
Thank goodness for utube for guidance and to Sim Yamaha for parts list.
I won't go through the whole process but I will offer some tips and findings.
I purchased top quality spanner wrenches made for the cylinder caps on my motor. They were not cheap but worked very well. You need two different wrenches since the spacing and pin diameter are different on the tilt cylinder and the two trim cylinders. Use the safety stop to hold up the motor.Do nor drain the hydraulic fluid as some posts had suggested.
I did the trim cylinders first since they were easier to do and it actually made the whole job easier. I had to add a longer pipe to my breaker bar to free the cylinder cap but no hammering was needed, just a good pull.
Remove, reseal and replace one cylinder at a time. Why?? The pistons tend to stick and instead of needing a special piston shaft pulling tool, I used the tilt switch to force some fluid into the cylinder I was working on. That helped free up and move the piston. Make notes of which way the seals face. Installing the inner seal is easier (but still tricky) from the bottom side of the cap. Install the outer seal from the top side of the cap. When installing the repaired piston, using the switch again in the down mode helped pull the piston into the cylinder enough to allow the cap to seat in the threads.
Once both trim cylinders were done, it was time to do the tilt cylinder. Loosen and unscrew the cap using the proper spanner tool. Remove the circle clip from the upper pin, remove the fat pin and watch out for the plastic bushings. There are four of them.
Retract the shaft again using the tilt switch. Swing the entire trim/tilt unit away from the transom. If the piston assemble doesn't clear the motor, lift the motor higher. I was surprised how easy that was to do from the safety position.
Now remove the whole piston unit. ( there is a small gotcha which I will explain later)
Unlike the trim pistons that can be slid out of the caps, the tilt cylinder has a head that the pin goes through. To remove the piston shaft, you have to remove the lower piston. There is a big nut 15/16 inch I think.
The nut may be difficult to turn and clamping the head knuckle in a vise will be necessary.
Here is the tricky part and thanks to a post I read for this heads up.
Under the nut is a washer. Under the washer are five springs. Inside each spring is a metal plunger that has a lip that faces down looking from the underside. Underneath each plunger is a VERY SMALL BALL BEARING that acts as a check valve.
If you hold the assembly right side up or don't realize that the balls are there, you may lose them.
Once they piston parts are removed, the piston can be removed from the shaft and the seals and o-rings replaced. The process is the same as for the trim cylinders.
The gotcha I noted:After I finished the rebuild I still had one o-ring left over. What the heck!
Turns out that in the tilt cylinder there is a second piston called the free piston. It doesn't automatically come out when you pull the main piston. It took me a bit of time to figure this out but after looking at the parts diagram over and over, I went back to the boat, and while looking into the open tilt cylinder, I pressed the up switch. The fluid pushed that second 'Free' piston up and out and sure enough, it has an o-ring on it.
To reinstall the free piston and the main piston, I again used the pump in the down switch position while pressing on the piston. That pulled in the piston. I had to do the same a bit more aggressively to pull the main tilt piston in enough to catch the threads.
Reconnect the main axle pin remembering to grease and install the four bushings, pop on the c-clip and you are ready to bleed. Add fluid to the reservoir and use the up switch until the piston goes all the way or struggles to move. Add more fluid and cycle the tilt and trim all the way down and back up. Repeat as needed until the tilt works its full range and the reservoir doesn't take any more fluid. I used a plastic syringe to add the fluid.
So not counting the time taken to figure out where the last o-ring went, the job took 2-3 hours.( I slept on the issue of the extra o-ring
) Getting the hang of installing the lower seal took time and experimentation but as mentioned, install them from the underside of the caps and use something like a dowel to push them into place to avoid damaging the rubber.
I was lucky that all three caps came off without damage and without excessive force.
Total cost? About 90 bucks for the parts kit and $150 for the two spanner wrenches. Probably less expensive then having it done at a shop and having to trailer the boat to the shop. Besides, it was a challenge and turned out well.
Hope this helps somebody.
Seasick
Last week I resealed my tilt and trim cylinders on my 18 year old 150SX motor. They started to leak at the end of last season (saw an oil sheen on the water at the dock)
Thank goodness for utube for guidance and to Sim Yamaha for parts list.
I won't go through the whole process but I will offer some tips and findings.
I purchased top quality spanner wrenches made for the cylinder caps on my motor. They were not cheap but worked very well. You need two different wrenches since the spacing and pin diameter are different on the tilt cylinder and the two trim cylinders. Use the safety stop to hold up the motor.Do nor drain the hydraulic fluid as some posts had suggested.
I did the trim cylinders first since they were easier to do and it actually made the whole job easier. I had to add a longer pipe to my breaker bar to free the cylinder cap but no hammering was needed, just a good pull.
Remove, reseal and replace one cylinder at a time. Why?? The pistons tend to stick and instead of needing a special piston shaft pulling tool, I used the tilt switch to force some fluid into the cylinder I was working on. That helped free up and move the piston. Make notes of which way the seals face. Installing the inner seal is easier (but still tricky) from the bottom side of the cap. Install the outer seal from the top side of the cap. When installing the repaired piston, using the switch again in the down mode helped pull the piston into the cylinder enough to allow the cap to seat in the threads.
Once both trim cylinders were done, it was time to do the tilt cylinder. Loosen and unscrew the cap using the proper spanner tool. Remove the circle clip from the upper pin, remove the fat pin and watch out for the plastic bushings. There are four of them.
Retract the shaft again using the tilt switch. Swing the entire trim/tilt unit away from the transom. If the piston assemble doesn't clear the motor, lift the motor higher. I was surprised how easy that was to do from the safety position.
Now remove the whole piston unit. ( there is a small gotcha which I will explain later)
Unlike the trim pistons that can be slid out of the caps, the tilt cylinder has a head that the pin goes through. To remove the piston shaft, you have to remove the lower piston. There is a big nut 15/16 inch I think.
The nut may be difficult to turn and clamping the head knuckle in a vise will be necessary.
Here is the tricky part and thanks to a post I read for this heads up.
Under the nut is a washer. Under the washer are five springs. Inside each spring is a metal plunger that has a lip that faces down looking from the underside. Underneath each plunger is a VERY SMALL BALL BEARING that acts as a check valve.
If you hold the assembly right side up or don't realize that the balls are there, you may lose them.
Once they piston parts are removed, the piston can be removed from the shaft and the seals and o-rings replaced. The process is the same as for the trim cylinders.
The gotcha I noted:After I finished the rebuild I still had one o-ring left over. What the heck!
Turns out that in the tilt cylinder there is a second piston called the free piston. It doesn't automatically come out when you pull the main piston. It took me a bit of time to figure this out but after looking at the parts diagram over and over, I went back to the boat, and while looking into the open tilt cylinder, I pressed the up switch. The fluid pushed that second 'Free' piston up and out and sure enough, it has an o-ring on it.
To reinstall the free piston and the main piston, I again used the pump in the down switch position while pressing on the piston. That pulled in the piston. I had to do the same a bit more aggressively to pull the main tilt piston in enough to catch the threads.
Reconnect the main axle pin remembering to grease and install the four bushings, pop on the c-clip and you are ready to bleed. Add fluid to the reservoir and use the up switch until the piston goes all the way or struggles to move. Add more fluid and cycle the tilt and trim all the way down and back up. Repeat as needed until the tilt works its full range and the reservoir doesn't take any more fluid. I used a plastic syringe to add the fluid.
So not counting the time taken to figure out where the last o-ring went, the job took 2-3 hours.( I slept on the issue of the extra o-ring
) Getting the hang of installing the lower seal took time and experimentation but as mentioned, install them from the underside of the caps and use something like a dowel to push them into place to avoid damaging the rubber.I was lucky that all three caps came off without damage and without excessive force.
Total cost? About 90 bucks for the parts kit and $150 for the two spanner wrenches. Probably less expensive then having it done at a shop and having to trailer the boat to the shop. Besides, it was a challenge and turned out well.
Hope this helps somebody.
Seasick
