When I bought my car 18 months ago I negotiated a good price because the suspension pump was tad noisy. I finally got around to having one from a breakers put on, easy job, £70 part and £40 labour. When I picked it up afterwards the steering had a slight wobble at low speeds. I took the front wheel off today and found it binding, but not all round. When you take a wheel off the front you also release the disc. I little bit of crud had got behind the disc, only a tiny bit, but it prevented the wheel from sitting flat on the hub. So it confirms what we all know, always make sure the mating surfaces are clean, it's amazing how just a tiny bit of flaky rust can have such a bad affect on it. Wobble free now!