Stiff steering

A Q I have owned my 2004 Vauxhall Astra 1.7 CDTI since it was three months old. It has now covered 128,000 miles and is very reliable and economical. However, I have a problem with the alternator/power steering. As the steering was excessively stiff, a new alternator was fitted in 2011, then again in 2016 due to the same problem.

Last May, there were three instances within 10 days when the steering would be very stiff on start-up. Each time, I was able to turn off the ignition, after which the problem would clear up. I understand how the electric pump helps the steering, but can you suggest anything I can do to stop the stiffness from recurring? John Whitlam

The first point to establish is whether the problem is related to the battery voltage or the steering gear. I would first check the battery voltage and the charge rate to ensure that the battery and charging system are in good order. It may be that the battery is no longer accepting or holding a charge, which would certainly affect the steering first thing after a start-up.

If you find no faults with the battery or charging system, it’s possible the power steering pump (electro-hydraulic supply unit) is failing. Check the condition of the electrical connections and also ensure that the fluid has not blackened as this would be an indication of impending failure. Any faults within the electro-hydraulic unit should be detectable using Tech 2 diagnostic equipment.