Lower pressure for HP M377/M452/M477, duplex model

[cipinet]

Hi, guys!
I searched for lower pressure for those models but specifically for duplex fusser unit, until now what I found not work, just don't fix/smeared toner on paper when print.
From where to buy such part/item? Sorry but english is not may main language.

[Wild Bill]

I would ask in the the Printer /HP
Also, I would just replace the fuser as a whole OEM or refurbished

RM2-6460 M452 duplex / fuser assembly