Just finished installing hydraulic steering with autopilot and wanted to share some useful information and photo gallery.

The players: Seastar 5271 helm, 5313 cylinder, Seastar nylon tubing w/fittings, Raymarine type 1 autopilot pump, S1G core pack (computer, compass, rudder ref TD), ST8200 AP control head, DSC VHF radio

Ordered the tubing and additional T fittings and 90* elbows. Needed extra fittings for the autopilot isolation valves and helm tubing layout. Also ordered the fill tube ($15) that has the fittings for the helm fill and fluid bottle. We were happy that the bottle fitting threads fit a plastic soda pop bottle.

Removed old helm and cable and sent it to forum member Clark Ogden of Lake of the Ozarks, Mo.

Applied Teflon pipe sealant to fittings and installed on helm pump. Had to cut a larger hole in the console so it would fit. Tightened helm into position. Secured steering wheel onto shaft. Nice fit.

The hydraulic cylinder base plate aligned with the vertical brace that the old steering cable was mounted to. Set cylinder to correct altitude, leveled, and clamped into position. Tested for tolerances as per instructions and made adjustments. Marked, center punched, and drilled four 5/16" holes. Secured with SS bolts and nyloks. Connected rod end to tiller.

Applied Teflon pipe sealant to fittings and installed on autopilot pump. Made adjustments to fitting orientation to match up with tubing layout. Mounted pump on a piece of 2 X 4 for clearance over the SB exhaust hose. Crimped butt connectors to motor leads, sealed with heat shrink, and pulled wires to helm.

The 50 feet of stiff nylon tubing had a bad case of "coil memory". To cure this, we had to stretch it out and use a heat gun to make it lay down. Also used the gun to custom fit the tubing at the helm pump elbows. Using a tubing cutter, three 14 foot lengths were made to go from helm to AP pump. Two pieces were cut to go from pump to cylinder as needed. Purged tubing with compressed air to exhaust any particulate and taped up ends. Laid into bilge, pushed into fittings and tightened nuts 1 1/2 turns. Put chafe guard around tubing where it was needed and cinched with nylon ties.

Went to the local aircraft supply store and got a gallon can (yes, it came in a metal can) of MIL SPEC H-5606 hydraulic fluid for $30. WM wanted $17 for a quart. Used a clean liter pop bottle that was filled via a clean funnel.

Followed the instructions for fill and purge and repeated for the AP pump.

Took a weekend over to Muskegon to do sea trials. Steering worked great and no leaks.

Cut the rudder reference transducer mounting plate from a piece of 1/8" aluminum, 12" X 4". Mounted the TD and tiller arm pivot. Pulled shielded cable to helm.

Installed the AP computer in the head below the electrical wiring access compartment. The perfect spot! Had to shorten the towel rod to accommodate.

Since the VHF radio has to be at least three feet from the AP controller, it was moved to the port side wall. Mounted bracket, drilled 3/4" hole for wires, fished a tape into bilge, pulled the cables (NMEA, power, RG58 coax) and terminated.

Cut a 2" hole below the tach and moved the oil pressure gauge. Cut a 3 1/2" hole where the oil pressure gauge was for the AP control head and installed.

Mounted the fluxgate electronic compass above the storage rack in the galley.

Went to the Raymarine web site to find out how to hook up the NMEA/SEATALK connections for the multifunction display, GPS, AP, and DSC radio. After many emails and delays, I called and talked to the customer support supervisor (Winston Savage) explaining that the manuals do not show how all the components get interfaced. He sent a final email that cleared up all my concerns. He also sent a PC-SeaTalk-NMEA interface box and a SeaTalk auxiliary junction box....for free Jeff.

Routed all cables and terminated, put labels on cables, and tied everything up.

Turned AP on and performed initial checks. Went through the dealer calibrations. Entered MMSI ID number into radio to enable Digital Selective Calling. Pulled boat out of garage to get a satelite fix. Checked MFD, radio, and AP for GPS signal. It's good to go.

UPDATE: Performed seatrials on 7/4/2008 in Mackinaw City. Autopilot would not autolearn. Talked to Raymarine tech. Had to move compass out of the electrical compartment.
UPDATE: 9/08 - Autopilot is now working fine.

Pictures here.

Thanks for the careful writeup. I bought a cylinder and pump as surplus a few years ago and I plan to put hydraulic steering in the flybridge when time permits. I steer from up there most of the time, anyway.

I don't need the autopilot, I already have one. If yours breaks, I can send her up to help out. You'll have to feed her and take her to school, tho.