As I mentioned on an earlier post, the seals on the backstay cylinder were leaking. of course after I had mucked with it it was worse, so I knew I had to rebuild the thing.

After taking the cylinder off the backstay, you have to dismantle it by removing the end cap. this is held in place by a small allen screw. The larger one holds the seal cylinder in place and also must be removed.




There is a tool available for taking off the end caps, but unfortunately I don't have it. Considering this is the sole hydraulic on my boat, it's not an investment I would make. I don't like that it scratched the finish and in retrospect I could have wrapped it with duct tape first.



The end cap just screws off.




First thing is to dig out what's left of the dust gasket (not much).




Because the gasket had crapped out long ago, salt and rain water had puddled in the unit, causing corrosion. fortunately, this surface doesn't actually contact anything so no real harm done.





With the cap off you can see the sealing cylinder. It's held in place by the hose fitting and the large allen screw.




This cylinder holds the seals for the actuation rod.




You have to remove the hose fitting before you can pull out the piston.




The piston seal. There was about 1/4" of oil in the bottom of the cylinder which isn't much after twenty years. It appears to be in good condition but might as well replace all the rubber parts while I'm at it. I was able to source parts from Coast Industrial (Navtec would have been waaay more expensive). About twenty dollars to reseal the unit.




The hose fitting has to be sealed with teflon tape or a liquid equivalent before reinstalling.




Once reassembled you pump up the ass end of the cylinder with a bike pump.




Good to go. twenty bucks later and it should last another twenty years.



I also decided to fix the engine alarm system. Turns out there were problems (of course). First of all the low oil pressure fitting was all corroded up and there was no contact with the spade fittings. Like I say in my book, friction-fit spade fittings have no place on a boat. the wires should be soldered to the fitting. The other thing I discovered was that a PO had replaced the alarm but installed it without paying attention to polarity. It will not work wired backwards, which is why it didn't go off when the engine overheated. People who don't know what they are doing should not work on their boats; that mistake could have cost me an engine and I would have been talking to lawyers.

Update on my previous post. Success! The engine runs at a nice cool 170 degrees now, at least 20 degrees cooler than it has been. I think the problems have been building for awhile now.