You can use the " insert constrant " for the two base trabalho.
then you can use the " insert constraint " for the base trabalho and the bomba codo.
You shut use the " mate constraint " for putting the pistons in site the holes of the bomba codo. ( use the centerlines )
The best way is to use the " insert constrant ", where the pistons meet each other (the holes)when you open constraints, it is the fourth counting from the left side.
There are many ways to do this, but this is one of them.
Now you can start with try and error. Have some fun.
But you draw the pistons not right, de flat sites with the hole, should be placed out of the center. because now it is not possible for real.