I know there is a very bad result from losing a power steering pump or throwing a belt off the pump at high rpm.
Has anyone ever explored using a 12 volt hydraulic pump as either a main or as a back up if the other fails for steering???
This is just a thought for discussion....would it be safe???

Ive been tossing this idea around. It only works for twins, but why not run both pumps and figure out a way to hose it all together so if one does puke, the other is already working away.??? Although, Ive lost my pump before and didnt even notice it until I tried to dock.

I believe IMCO, WPM & Marine Machine have diagrams on how to plumb due pumps....but it is for only full hydraulic systems.....by your name I assume you are a 311 or 312 Formula? so that means you must be full hydraulic now with Latham???? I'm sure if you contacted Latham would supply you everything you need !! (just send the money !!)....but back to the 12 volt pump idea??? any thoughts???

It would use a lot of power. you would need a huge alternator. Those pumps use a lot of HP

They also have very little flow. Not nearly enough for the job.

Merc makes a priority valve kit to run both pumps- one is slave, one master. In case of pump failure, the spool in the valve shifts to pick up the other pump. Similar in princical to shuttle or priority valves we use in jet hydraulic systems. They offer the kit for both Saginaw and Brazil steering units.
A full helm to stern exrernal hydraulic steering system is not much safer than any other if driven by only a single pump and it fails. Any of the major external steering mfg's can help you set up a two pump system.
Having survived a pump failure at WOT (actually the engine driving the PS pump lunched), I highly recommend it in a twin install.

[ 01-15-2002: Message edited by: jafo ]

Maybe...DUAL 12 volt pumps (for flow) & install a small Honda generator for 12 volt power!! You could then use any surplus power to run the cabin air conditioner !!

93formula-
Send me pics when your done!

You got me thinking a bit about this. I posted a question to GVP on Boatered. He said this might be doable. Now this is internal not external steering.

I have twins with internal standard mercruiser power steering. I can add a second pump to the other engine, then either add a dual station helm like on cruisers or add a tie bar between the valves on the cylinders. But the dual station has 2 steering cables. Then add a second cylinder to the other outdrive and get rid of the tie bar between the tillers. Then add a tie bar too the outdrives. That way they would move together, and if I blew a pump, or lost a belt the tie bar would help transfer the load to the other outdrive. I'm almost there now, I have the tie bar, all I would need is a pump, oil cooler, cylinder and a dual helm type wheel. I wouldnt be using a second helm, but instead using a 2 cable helm.

Any thoughts. I need to replace the helm anyway because my old one is wore out, this may add some added insurance.

It would be very difficult to get two pumps to achieve exact pressure/flow outputs through two steering valve units with identical flow rates, let alone synchronizing two cables to work/rig exactly in unison. Helm steering cables usually don't fail, just wear, and a single Brazil or Saginaw valve served by a single cable is quite reliable.
Mercs priority system allows the second pump to `stand by', simply porting its flow to return unless called upon by a drop in pressure from the master pump (failed engine, pump, or drive belt).
It would be cheaper and more reliable to retain the internal tie-bar, add an external tie-bar (for safety's sake), add the extra pump and cooler, and connect both pumps to the priority valve kit.
The kit sells for less than $1K and is available from any Merc parts dealer.
The principal is the same for external steering but you'd be better off contacting your steering mfg. on exactly how to plumb it. It will still require two pumps.