The Offshore Voyaging Reference Site

Autopilot Installation Problems and Lessons Learned

The Problem

During the winter of 1996/97 I was single handing in the Caribbean and our trusty old Neco autopilot bit the big one. Gear always dies when you need it most! I replaced it with a Simrad autopilot controlling the old Neco rotary drive. After a few hundred miles of sailing, the Neco drive died.

I returned to St. Maarten and decided to replace the drive with a Simrad hydraulic pump driving a huge Hynautics ram attached to the quadrant.

Since I knew little about hydraulics I contracted with the Simrad authorized dealer in St. Maarten, that I had bought everything from, to install the hydraulics. I also had a local welding shop modify the quadrant and build a mount for the ram.

All seemed to go well with the new set up and two weeks later I left for Bermuda single handed. But two days out I found that the hydraulic level was low, there was oil leaking from every joint and the pump was making a horrible grinding noise.

Despite the manual’s clear instruction that special thread sealer must be used, the dealer had used ordinary pipe dope. I topped up the hydraulic oil daily and kept my fingers crossed; the grinding had to wait too, since I had no spare pump. I made it to Bermuda and on to Maine (we have a vane gear, so I was not totally without backup).


Once I got to Maine, I contacted Simrad USA in California who could not have been more helpful. They sent me a replacement pump for free, rebuilt the old pump (then gave me a great price on it as a spare) and spent several hours on the phone walking me through the process of pulling the whole hydraulic system apart, cleaning out the metal fragments from the pump and assembling everything properly with the right thread sealant.

The Outcome

Since then the Simrad autopilot has steered us some 100,000 miles in winds up to 45 knots (after that we tend to heave to) with the only problem being a leaking seal in the ram, that I suspect was damaged by pump fragments, which did not fail for a further six months.

Lessons Learned

  1. Don’t mix new gear and old.
    Trying to reuse the Neco drive was dumb.
  2. Authorized dealers don’t necessarily know what they are doing.
  3. Don’t blindly trust the professionals.
    1. Unless you know the technicians who are working on your boat and have absolute faith in them, watch them like a hawk and read the instructions they will be using prior to the work starting. If I had done this I would have caught the pipe dope. (In my experience, I would have received an argument along the lines of “Oh, that’s just the instructions, we always do it this way”, but I would have stuck to my guns and got it done right or fired the guy and done it myself.)
  4. You can often do a better job than the ‘professionals’ by reading the instructions and being methodical.
    Remember that the pro goes home at night, you go to sea; who is going to take more care?
  5. Have a spare autopilot hydraulic pump.
    This is a very heavily loaded piece of gear. We also carry a spare ram, rudder feedback device and control head.
  6. If you get contamination in an hydraulic system, replace every single seal.
    If I had done that, I would not have been messing with the ram six months later in Ireland instead of going to the pub.
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Bill Spohn

Always good to do your homework before tackling installation project especially one as important as your AP. Most hydraulic high pressure flare fittings are of the JIC type (37° flare) which require a metal to metal contact to seal. A drop or 2 of thread sealer such as locktite is ok but not necessary- only on the outside thread. What find more important is to pay close atttention to properly match your fittings SAE, NPT, BSPP ,BSPT and dont reuse a fitting w/damaged threads. This is where most leaks and contamination arise. In many ways hiring a qualified professional can save time and potential problems unless your a DIYer that doesnt mind a learning curve.