Auto Pilot pump is shot...time to replace so is it time to replace the fluid?

[northshoreone]

I have ordered the replacement pump but would like everyone's thoughts about flushing out the old fluid and replacing it with new. The question is how to do it the best way to get the air out of a long run through both helms? The pump is mounted at the flybridge helm.
Thanks

 

[saltshaker]

I have ordered the replacement pump but would like everyone's thoughts about flushing out the old fluid and replacing it with new. The question is how to do it the best way to get the air out of a long run through both helms? The pump is mounted at the flybridge helm.
Thanks

Not sure if you need to drain the system but if you do the best way is to drain it from the resevoir then open the lowest supply line at the steering solenoid on the rudder table. If your boat is like mine, all you need to do is refill, start the engine with the power steering pump and turn the wheel back and forth a few times. System will bleed itself. Check and top off the fluid after the first start if needed.

 

[Boatsb]

Unless there is debris from the pump head it's not necessary to drain and refill. If there is debris you need to clean it out too.

 

[Fanfare]

There is a sintered metal filter in my fluid resevoir which filters all the fluid over time. Should be adequate for all normal usage.

I did change my fluid once many years ago following a steering emergency where I had to mix ATF fluid with hydraulic fluid. I seem to remember that I found literature saying either fluid would be OK, but I was not comfortable with the combination of both. Good mil spec hydraulic fluid was easier to turn.

Mine is the very first Hatteras to have Hynautic steering, installed on special order instead of Crowell. Other than replacing the shaft o-ring, which wears due to dirt and age, no problems in 50 years.