trim cylinder seals

[johnsw]

2004 150 carb 2 stroke (150TXRC)

Finally got to do my mechanical checkout today. End cap seals on both trim cylinders are dried out, and popping out of the end cap. Tilt cylinder seal doesn't look the best, so probably time to do all 3.

Looks like the trim cylinders shouldn't be a problem getting to, since there right there in the open. But can the seal for the tilt cylinder be done without removing the tilt unit from the bracket?

Also, I've read that end caps can be really tough to turn even with the correct spanner wrench. Any recommendations on how to deal with a real stubborn one?

Other than that, seems like tilt works just fine. No fluid leaks. Holds engine up and doesn't slip.

Is this one of those jobs that should be relatively simple, but can be such a pita that it may be worth taking it to a mechanic?

 

[DaleH]

1st block that OB securely so you don't lose an attached appendage ...

Most items subject to saltwater can be a beyatch to get apart. Apply PB blaster, rap the fastener to try to help loosen it, but sometimes it takes judicious applcation of a heat hammer (torch), which can be touchy in that area, with hydraulic fluids et al.

Worst thing on tilt cylinders is usually getting out the top pin. Once had to use torch and a sledge hammer.

But I must add ... I have yet to ever have to have replaced a trim/tilt seal on any OB yet.

 

[windknotnc]

The trim cylinder seals are pretty easy to replace.....My question is why are you thinking about compromising a system that is not leaking. The seals that are bulging are the dust seals and not the main seal. The risks of messing up a system that is functioning without a leak are high. Dale is correct about the hinge pin, it can be difficult. You also may not find the seal for the tilt piston. I don't think it is a user serviceable part. That is not to say you can't take it apart and get to it, you just cannot buy the seal. It comes as part of a kit. You may want to research this a little, but be prepared to have to purchase the kit.

 

[johnsw]

I took a look at the exploded diagram of the PTT. I'm kind of on the fence with replacing the trim seals. The dust seals probably just keep the environment out. But will I just be delaying the inevitable?

The tilt piston seal I can probably leave as-is. It has a small crack so it's dried out as well, but it's still in place. And since it looks like the unit needs to come off to do anything with it, I'm inclined to leave that one go.

Thanks

 

[WAJSKI]

I had twin volvo duo prop on my cat boat cylinder was leaking no replacement seal kit, new cyl $459. I took mine to a shop that dose hyd cylinder repair (2) $125 for the pair, the guy told me isn't a seal made he can't replace. I would leave them alone if they aren't leaking, as stated before the seals that are puckering out are the wipers

 

[johnsw]

Yeah, I can see why this is another one of those 'if it ain't broke, dont fix it' kind of moments. If the end cap gets trashed, then I'll be looking at a bigger repair trying to replace the whole darn thing.

But the way I'm seeing it, it's damed if I do and damed if I don't. The dust seal is first thing between gunk on the rod and the main fluid seal that lays beneath it. A good dust seal probably prolongs the life of the seal that's keeping the fluid in the cylinder, since as you say, it's wiping the rod as it passes. So if I don't fix it, then I'm guessing it could be a few more years before that seal starts leaking, and then I'll have little choice but to do something about it. And like my Parker, I ain't gettin' any younger to work on these kinds of things.

As-is, I'm probably good to go for this season for sure. How much longer after that could be a sticking point.

If the top seal is just to keep most contaminants away from the main seal, seems to me Yamaha could have done a better job at designing it to be more easily replaced without having to disassemble the cylinder. It's exposed to UV and salt water environment, so it would make sense it's likely to be the first seal to go. But hey, what do I know.

Thanks again

 

[windknotnc]

If the dust seals are really bothering you, they really are not hard to replace. You will need that spanner wrench and a clean place to work. You also do not have to remove the unit to replace them. It is serviceable on the boat. I know I stated earlier don't mess with it unless it is leaking, but if they are really bad and water is going to get into the housing you should do something to prevent corrosion and possible water intrusion. How about posting a picture of the dust seals so we can have a look at the condition. I know on an earlier Yamaha I purchased, the seals were really bad and the housing that held them in place was shot and I opted to buy a used unit and rebuild it. You don't want to do this.

 

[johnsw]

I won't be back to the boat for a few weeks, so can't do pics at the moment. If I had my camera, I'd have done it since my cell phone is so old that it doesn't have a camera. (I'm one of those, 'but it's a phone' kind of people.)

Best I can describe is they're bulging out about 1/2 way around the piston rod by about 1/16" - 1/8". Seals on both trim cylinders have popped. Leaving them as-is, they should still keep most of the outside world out.

I don't see replacing the seals in the cap as being the difficult part. But everything I've read cautions that getting the end caps to screw off is what takes the most effort, and is the most risk of doing big damage. That's my hesitation.

But I've already ordered the spanner, end cap seals and o-rings. Figure next time I'm at the boat, I'll give it a try with a long breaker bar on the wrench. If it doesn't budge before the end cap starts to show the wear, then I'll figure it's not meant to be and just leave them and hope for the best.

But if I can do it, I'll try to document and post photos.

 

[johnsw]

Just some additional info. Do with it what you may.......

As suggested in another post, I tried again to remove the trim cylinder end caps with large channel lock, but that didn't work. I then tried to spin the cap using heat, chisel and a hammer and that didn't work. Makes a nice, solid THUD when I gave it a whack. So I stopped before mangling the cap too much to make a bigger problem. I'm really late in splashing this year, so I'm going this season without the dust seals.

I saw a tilt assembly on eBay from an '04 (same year as mine) 115 Yamaha for $400. Checked the parts diagrams for both, 115 and 150, and they were the same unit so I bought it. My plan is to rebuild this one over the summer and then deal with mine in the fall. Worst case, I'd at least get some spare parts out of it. (I'm one of those "Better to have it and not need it, than need it and not have it" people. Within reason.)

So I set it up on the workbench and not surprising, the same issues I have with mine are duplicated on this one. But this one I'm better able to work with. After getting the manual relief valve unstuck, I then moved on to the trim end caps. Didn't budge with channel locks or a pipe wrench. So I took the lip dimensions from the replacement end cap I have and used my Dremel with a cut off wheel to take off most of the lip that contacts the top edge of the cylinder, piece by piece. I didn't cut deep enough to go completely through the lip of the cap. Just enough so that I could bend the edge up and down a few times to snap it off, leaving the cylinder edge that it mates to undamaged and untouched by the cut off wheel. Then a few whacks with a hammer and chisel against an exposed edge of the end cap that I deliberately left uncut, and off she spins.

This method worked for me to get the trim end caps off the unit. The problem doing the tilt rod end cap this way, is it doesn't look like that cap is sold seperately (unless I'm reading the parts diagram incorrectly). For that one, the tilt rod needs to be replaced as it looks like that end cap is part of the rod assembly. So not sure what I'll do with that, but I'll deal with it when I get to it.

I figure I'll rebuild this one with all new seals and o-rings and have a spare, just in case. I can either swap mine out in the fall and do another rebuild over the winter, or try removing the caps on mine while on the boat using the cut-and-whack method.

 

[windknotnc]

You should take those cylinders to any hydraulic shop and they can unscrew those caps in 30 seconds. They have the right tools and do this stuff every day. I had mine broken loose and they didn't charge me anything.

 

[johnsw]

You're probably correct. The caps are off the one I'm rebuilding, so not an issue with that uint. If I remove my original trim and decide to not service it on the boat, then this is definitely an option.