I use a press about 15tons pressure on Front Wishbone Arm without sucess... Does brake fluid could be use?

 

Which arm, there are two, one straight the other curved.

They are aluminium forgings so some heat in the form of boiling water (couple of kettles), will expand the aluminium housing more than the steel outer of the bush. The coefficient of expansion of aluminium is double that of steel.

 

Heat makes the job a lot easier. I used a heat gun...carefully.

 

And freeze the bushings in the freezer before pressing.