This is my first diesel pickup, and I am completely new to this type of braking system. I have about 120K miles on this puppy and I was going to change my brake fluid today. When I opened the hood and looked behind the master cylinder I do not have the pancake vacuum for the fluid. From the research I have done on this forum I believe this piece is called the hydrobooster (I think).

When I looked at the piece behind the master cylinder there seems to be a slow leak on this piece. There is fluid that has leaked out, and dirt and grime have attached itself to this piece. I am wondering what the part number would be to replace behind the master cylinder.

Also I always thought a diesel pickup used power steering fluid to stop b/c a diesel does not produce a vacuum. However, when I looked at the writing on the master cylinder it said to use only DOT 3 fluid. So I guess it is a completely separate system from the power steering, correct? Thanks for the help.