I've owned my 2007 GL450 for over 10 years and have put 225,000 miles on it. The steering became more difficult a couple of years ago and I was getting a clunking sound over bumps. It turned out to be the mounting point bushings for the rack to the sub frame. Long story short I had the rack along with the power steering pump replaced as it all was getting old. Generally, the steering feels good now except for when the vehicle is cold. When I start it cold, the steering is quite difficult. But I've found that if I turn the vehicle off and on again, it often steers with minimum effort and feels totally normal. Any ideas on the cause of this? Thanks.

Was the power steering fluid reservoir changed out with pump? Also are you running the correct fluid?

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Jim

The power steering pump reservoir was replaced and the correct fluid was used.