A steel brake pipe under the car "exploded" during the MOT test, I was told that the brake pedal was heavily loaded in a similar way to that in an emergency stop.  The garage will replace the pipes with copper.  I was also told that any corrosion of the pipes cannot be seen during the MOT test because there is a plastic cover over them.  Can anyone please confirm that there is a plastic cover over the brake pipes under the car, I've looked in Haynes but there are no pics.     Perhaps I