Can anyone help this so callled mechanical engineer whos lost the plot!.

Power steering issue 2018 custom with 58K miles.

When fluid cold no issues.

When fluid hot 65deg C on hard lock splines wine and hard to steer. When moving stationary nearly imposible to turn and wines like ****.

Items checked.

Fluid bang on cold mark when cold and hot mark when hot. Crystal clear no contaminant, and no milky residue from perhaps a leaking low pressure pipe? Pipes and joints checked.

Alternater pulley and jockey wheel fine. Serp belt as new. Belt tensioner fine but worked it anyway. Worked steering till my arms ache (wheels off) splines wine on full lock held on.

No deterioration to steering rack as can see. I am trying to dismiss the pump since hydraulic fluid is fine and its only done 58k and not been abused works fine when cold no issues.

Thought fluid may have lost viscocity as monly wines when hot but its not over heating and clear, but going to change it monday anyway.?

Edited November 8, 2025Nov 8 by PaulHarr
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2 hours ago, PaulHarr said:

Can anyone help this so callled mechanical engineer whos lost the plot!.

Power steering issue 2018 custom with 58K miles.

When fluid cold no issues.

When fluid hot 65deg C on hard lock splines wine and hard to steer. When moving stationary nearly imposible to turn and wines like ****.

Items checked.

Fluid bang on cold mark when cold and hot mark when hot. Crystal clear no contaminant, and no milky residue from perhaps a leaking low pressure pipe? Pipes and joints checked.

Alternater pulley and jockey wheel fine. Serp belt as new. Belt tensioner fine but worked it anyway. Worked steering till my arms ache (wheels off) splines wine on full lock held on.

No deterioration to steering rack as can see. I am trying to dismiss the pump since hydraulic fluid is fine and its only done 58k and not been abused works fine when cold no issues.

Thought fluid may have lost viscocity as monly wines when hot but its not over heating and clear, but going to change it monday anyway.?

Have you checked the rubber pipe bits aren't collapsing when it's hot as given from what you've said that could be the only possibility given on full lock it would be pushing max pressure through it Elland if any of the rubber pipe sections are near a heated part it could be causing them to collapse due to the amount of pressure ?

As to milage l wouldn't go by that I'd just look at the fact ford have been doing all they can to make it harder to self repair if not aim to make replacement of the whole vehicle the only option..