Troubleshoot stiff power steering

[Jokke]

After the winter the power steering on my 1984 18 foot Wellcraft with 1995 130hp Mercruiser 3.0 litre suddenly has become stiff especially turning to the right.

There’s enough fluid in the reservoir.
I’ve taken off the cable. I can easily move the cable back and forth inside the tube by hand. But the big nut broke off the cable tube when I took it off. I thought it should be able to stay static by me clamping it, while I turned the nut to get it off the steering actuator. Apparently not. So I need new cable.

Question is: since I didnt find any issues other than what I introduced myself what next steps do you suggest for troubleshooting?

 

[Jokke]

[No message]

 

[alldodge]

If the tube threads are intact with the nut breaking off, then a new cable can be reattached

Stiff steering is either the power steering pump and/or the steering ram.

The steering ram needs to have the flats on the tube face up and down (upper right)


If pressure from the pump is providing sufficient pressure then pump is good. Pressure should be 1150 - 1250 psi on high side, and 70 to 125 psi low side

 

[Jokke]

Here's a close-up photo of the part that is broken - leading me to think I need a new cable.

Guess I would need some kind of pressure meter to measure the pump pressure... Or is there a way to test if the pump is working that doesn't require a pressure meter?

 

[alldodge]

Looks like the ps tube was not damaged.
No way to test pump without gauge

Most cases it is the pump hat goes out. Would be good to know if the flats where straight up and down before the cable was removed, but then again it normally doesn't move once set.

Easy enough to replace cable and then see if the issue remains

 

[Jokke]

Thanks AllDodge.
The flats were straight up and down. At the very end of the cable that goes through the power steering tube there's a vertical pin hole (G, F, H on the diagram you provided). When the pin is in the flats will have to be straight up and down.

I finally got a replacement cable today. Will mount it tomorrow and report back.

 

[Jokke]

I have to take my words back AllDodge - the pin can be inserted while the flats can be in any position, as you said. My misunderstanding.
They are now in the right position and the new cable is in. The wheel turns super easy before attaching the cable to the power steering actuator. When I attach the cable and the power steering actuator the wheel does not feel any where near as easy to turn.

It's not possible for me to tell if there is still an issue. I guess I have to attach a water hose and fire up the engine to get oil pressure to see if that makes the wheel turn easily or not. Perhaps even have to take it for a real run to feel how the steering handles under pressure from the drive.

 

[alldodge]

Its normal for steering to be a bit harder once cable is attached, your now moving the drive and bending the bellows.

The flats being straight up is to align the ports inside the steering ram with the tube. You won't know the PS is working without the motor running

 

[Jokke]

Ok, so with motor running the power steering oil pump is definitely assisting. I can easily turn the wheel to left with a finger, to the right I need a full one hand grip to turn it easily.

Is it normal / expected to have such difference between how hard the steering is towards left and right?

I have yet to discover how hard or easy the steering will be when the boat is in use and the drive is under load from acceleration in water.

 

[alldodge]

Not being in the water, and not sure but I think your ram is the issue. It should be real easy both directions and not being in the water even more so. Its hard right so the valve in the ram would be my guess as the issue.

Might be the valve is gummed up

 

[Mad Props]

Have you tried disconnecting the steering ram from the tiller arm on the drive and then moving the drive back and forth by hand? Wondering if it could be the actual drive binding up on the steering pin or something... Maybe worth a check...