What was found
(JRUR) A 1.5 INCH LONG CRACK WAS DISCOVERED IN THE FIREWALL FWD DOUBLER (PN 0753600-24). THE CRACK WAS LOCATED ON THE LOWER LT QUADRANT OF THE FWD FIREWALL DOUBLER. THE CRACKED LOCATION CAN BE FOUND BY LOCATING THE "BRACKET-PARKING BRAKE CONTROL" AFT OF THE FIREWALL (SEE IPC REV 19, CHAPTER 32-32-02, FIGURE 01, ITEM NR38, PN 0713070-20) . TRANSLATE THIS LOCATION TO THE FWD SIDE OF THE FIREWALL. THE CRACK WAS CENTERED AROUND THE TOP RIVET ATTACHING THE "BRACKET-PARKING BRAKE CONTROL" TO THE FIREWALL AND FIREWALL DOUBLER. WHEN THE PARKING BRAKE HANDLE IS PULLED, THIS AREA OF THE FIREWALL & FIREWALL DOUBLER FLEX A LITTLE. IT IS VERY PROBABLE THAT THIS FLEXING ACTION HAS CAUSED THIS CRACK IN THE FIREWALL DOUBLER. 2 SMALL DENTS CAN BE SEEN IN THE FIREWALL FROM THE "BRACKET-PARKING BRAKE CONTROL".