how can i fix my(rover 25) power stearing?

my car had a major power stearing leak.... i put the car in to a garage and was told that there was a loose bolt on a presurised pipe on the stearing rack..... the mechanic told me that it would be a few hours work because he had to drop most of the sub-frame out to tighten the bolt..although he only had the car for an hour....i'v had the car back for a week now and the same thing has happend again is it true that you need to drop the sub-frame out on the rover25 to get at the stearing rack???