seafirst steering extremely hard to turn

[dalotrico]

Hello- recently put together my steering system on new boat which includes 2 Seafirst 50cc helm pumps, 1 3/4 bore / 13.8cu in Seafirst ram, msh-6 parker 3/8 hose with swaged on fittings filled and bled using aircraft (have a flyer friend) spec 5604 hydraulic fluid. Very smooth plumbing. 13.5″ steering wheel. Only 90 fitting is at cabin helm where there is a tee to the bridge helm. Not sure where I went wrong here. Steering is silky smooth when prop (26×26) is not turning. I can get full throw 90 degrees back and forth. 4 1/2 turns lock to lock.  With the prop in gear, I can get 10-15 degrees and then it’s very hard to turn. Thinking maybe the ram is too small for the helm pump size? Just a leverage issue?

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[Tony Athens]

stiff steering from prop trust / wash

How about too much rudder, not enough leverage on the steering wheel ( under  7″ radius),   probably need a larger displacement ram (more turns lock to lock) , plus what looks like a lot of turbulence between the tunnel and rudder shoe supports………………………..Where would you like to start?  If me, so you can see what is going on, it would be nice to measure the pressure in the system when it gets hard to turn–

Is it going into a turn, coming out of at turn,  or both? Important,  as “balance” affects that a lot.  Post an accurate drawing of your rudder

Once steering pressures rise above 500 PSI with a tiny steering wheel, things get stiff.

[Author]

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