citroen berlingo 1.9D 2004 - jerking steering - kandkspares

i have a 2004 citroen berlingo multispace 1.9D and it has a very bad jerking movement in the steering as i turn into corners, i have changed the power sreering pump but no joy and the jerking is still there

citroen berlingo 1.9D 2004 - jerking steering - Peter.N.

Is it a belt driven pump? If so they are classic symptoms of the belt slipping.