JHZR2,

The fuel pump is removable from the IP and is a replacement part. You don't have to replace the IP to replace the fuel pump. I don't know the cost of a fuel pump as I never replaced one. They seem very reliable.

I don't know the internal mechanizm of the original fuel pump but I don't think a slight pressure on it would hurt it. Can't say for sure though.

I knew a guy that had a bad pump on a MB DIesel and he replaced it with an electric pump and it worked OK.

P E H