Power steering full power to right. No power to left

I had the front suspension out and replaced all rubber bushes,springs, shock absorbers and sub frame mounts. I left the power steering box on the subframe capping off fluid holes. I had trouble with the lower A frame shafts seized in the subframe and used heat and air hammer to drive them out. Reassembled everything using good used shafts and all new bushings and subframe mountings. Attached the power steering hoses and filled the reservoir with correct type F fluid. Immediately on starting car the power steering would go to full power to the right and no power steering to left. I took the car for a drive to see if it would settle down which it didn’t. I disconnected power steering hoses and blew compressed air through to inlet and out let ports. Topped up reservoir and tried it. Still the same. I’m wondering if anyone has experienced this before with the Burman steering box. I don’t know what it could be as I didn’t even have the box off the subframe. Any help would be greatly appreciated. Cheers. John.

Just a long shot, can the hoses be cross fitted?

Hey robin thanks for your reply. The hoses only go one way as the pressure hose fits on the front of the box with and pressure fitting and the return hose has just a hose clamp. Appreciate your help. John.

I’ve read the O/p’s reply to your post, but this would seem the most likely reason for the power to be applied incorrectly.

Power steering works by the power ram having two feeds into the cylinder, which due to one side being behind the piston, has the shaft, so a smaller cross sectional area of exposed piston.
The pinion valve uses a torque shaft to hold both sides pressurised so one side has half the pressure of the other.
As the pinion valve rotates it depletes the pressure one side of the piston, or the other, thus the power ram moves.
Typically the pinion valve has three seals and four grooves. The upper and lower seals are to stop external fluid leakage, the centre seal is there to create the pressurised feed.
Depending on whether the seal is in the upper, or lower groove is dictated by whether the car is Lhd, or Rhd.

Has the steering box had new rotary valve seals installed, if so, the centre seal needs moving to the other groove.

Hi diesel man thanks for your reply. The steering box has not had any work done on. I removed it still attached to subframe only removing the hoses and steering shaft coupling. It’s as though something inside has stuck and allowing fluid to flow only one side. Cheers.


I have just finished to rplace steering rotating valve seals in a 4.2 Mk10. I supose the rotating valve is similar. Refering to your problem, could be perhaps that one of this seals is broken or leaking and oil pressure escapes from pressure area on the valve to one of the piston faces?
Replace this seals in the 4.2, is not difficult but requires extreme care.

Jesus Sanz

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Thanks Jesus I suspect you are correct. I’m taking th steering box to a specialist next week. I’ll post the findings. Thanks for your comments.