Are you getting errors about the ink absorber pad? Like "Ink Absorber is Full"
How old is your printer. The ink absorber pad doesn't wear out that easily.
I think you issue is related to the printhead nozzles that are getting clogged and you might need a Brother printer head cleaning kit
If still you want to replace the ink pad, then you have to get a Bother 'ink absorber box'.
You should be able to find them on eBay.