On my BMW 325i my power steering pump was replaced last year but I’m not sure if it was flushed properly .and I’m also not sure if the belt was put on correctly but would that cause my power steering system to fail a year later .
What part failed? The replacement pump or the rack?
Very hard to put the belt on wrong.
In my own limited diy’er power steering experience (hydraulic, no electric), as long as the PS fluid is at the correct level, PS systems usually work the air out by themselves just by the driver turning the steering wheel back and forth. If belt tension was way too tight, that could damage the bearings of the PS pump. But not something that would be likely to occur. More likely the replacement pump was faulty from the get-go. Ask your shop to use an oem replacement pump. Hold on to your wallet, but that money will be well spent.
If you’re car is an E46 they had an issue with the pas pumps, they may have replaced it with an LF 20 pump (written on the side on a white label) that’s the old design a replacement should be an LF 30 with new hoses