I changed over the Aternator with lots of swearing. started engine, all good

could hear a minor ringing sound so thought maybe i had tightened the alt belt a little to much. took the PSP off again to get to the adjusters and then replaced everything.

now the PSP is maiking this noise and the PSF in the bottle is very foamy.
have i trapped air in there? how do i get it out? help please. all was great till i decided to adjust it
