Sea star hydraulic fluid purge and fill

[usmarine1]

I just bought a boat and checked the fluid level on top of the steering column. The book says no more than 1/4" below the fill hole. Of course it is like an 1". The steering is great back and forth very smooth. My question is and I'm afraid I know the answer will I still have to purge the system being it's lower than it should be? Can I just "top it off" and pretend like I saw nothing? First time with hydraulic steering. Also is it necessary to do preventive maintenance annually or are they pretty much no fuss as long as it's clean, greased, and not low/leaking fluid and hoses are in good condition? Thanks for any advice.

[omc frank]

Got to the back grab the motor if you can move it more than 1" stoke of the rod you best bleed it (LOT OF AIR IN THERE)
May check with local dealer if they have a power purge machine we only charge 50 bucks plus fluid to bleed
they just pug machine in turn it on its done in a couple minutes no mess either.

[chysteve]

With that small amount low, I just fill mine, leave the cap off and turn the steering wheel a few times. Seems to bleed out the small amount of air in the line. Can't hurt to try rather than a full purge to start with.

[staylor]

usmarine- Are you measuring the level at the steering box- or at the end of a fill hose that comes out of the box and heads upward to a fitting on the console? If you're measuring at the box, just add fluid up to the 1/4 inch level. If you're measuring at the console fitting look down the fill port on the console and you'll see a section of the fitting that has a reduced diameter about 2 inches down- fill to this reduced diameter section such that when you jiggle the wheel back and forth oil does not rise above the reduced diameter section. Do not overfill the Seastar- it can get messy if you do- and don't ask me how I know this!

After filling to the proper level- whether at the box or at the dash fitting, cycle the wheel back and forth fully 2-3 times- turning a bit past the ends of travel to exercise the pressure relief valves- and get any air bubbles out that may be trapped in the valve. Lastly- work the lower unit back and forth by hand and check motion at the Seastar piston rod where it goes into the cylinder. My system has been bled several times and I'm currently at a little less than +/- 1/16 inch motion- anything under 3/16 inch is OK- but if your rig runs above 55 mph the steering may get a bit flaky with 3/16 inch since the play will allow chine walking to start on many vee hull rigs. If it's more than 3/16 you should probably purge the air from the system- a 2 person job- unless you have access to a power purging unit as omc frank posts.

There also should be a slack adjustment nut- a large diameter split plastic nut- on the motor's tilt tube. This usually has a small Allen head bolt across the split to lock the plastic nut in place. To adjust, loosen the Allen head bolt 1-2 turns until you can just turn the plastic nut, loosen the plastic nut 1/2 turn and while jiggling the cav plate back and forth hand tighten the plastic nut until all play is removed and the plastic nut gets hard to turn by hand. Do not over do this- if you tighten the plastic nut too tight it will get stuck between threads and will be loose again after the first fishing trip. Retighten the Allen head bolt to lock the plastic nut in place.

In most cases you will only have to add a very small amount of fluid at the beginning of each system.
Doug

[usmarine1]

Thanks everyone, it's been a bit since I've been able to get in the shop. Yes it's right at 3/16" of travel no more. I topped off the resivoir at the steering column and it seems fine still. I have read elsewhere 55-57 mph is top for this rig, but that remains to be seen lol. If I can find the slack adjustment I'll also tighten that per your instructions Doug. Hopefully this will keep me from having a bad time on the water or spending a small fortune replacing it.

[staylor]

If it's a standard Seastar system it's rated for up to 75 mph with the below restrictions:

CAUTION: Not recommended for use in installations where;
a) Chopper, cleaver or surface piercing propellers are used,
b) The engine is highly elevated on the transom,
c)Engine trim tabs have been removed,
d)The boat speed exceeds 75 mph (120 km/h), or
e)The power exceeds the maximum Coast Guard or M.O.T. recommendations for the boat.

I'm running at 62-63 mph with my current Starcraft with the engine raised up 3 holes(prop shaft centerline 5 inches below bottom of boat) and a flat Merc plate replacing the trim tab with no issues- but as I noted in a previous post my system is running with only +/- 1/16 inch motion at the cylinder when the cav plate is shoved back and forth.

The adjusting nut is shown as item 10 on page 18 of the installation manual at:
http://www.seastarsolutions.com/wp-c...3/296784AT.pdf

Doug