I will be installing an auxiliary braking system in my 2016 F150 4x4 to tow it behind my motorhome. One of the systems i am looking at requires an actuator cable sleeve thru the firewall directly behind the lower part of the brake pedal arm. Does anyone know if the firewall is a single thickness or double wall metal in that area? I have pulled the carpet back and looked but there is sound insulator inside and heat/sound insulator outside that i havent removed. It looks like single wall nearby due to steering and brake booster mounting studs. But i suppose Ford could have added bushings between the layers at these points and it might be double wall.

 

Do you need access to the engine bay?

Do you have an e-parking brake or manual? If manual, follow the parking brake's cable to the back of the firewall. Pull the plug on it with some pliers and you get access to the engine bay.

 

The reason i was asking is one of the braking systems is a cable pull actuation of the brake arm where the cable must pass through a hole directly behind the brake arm. But im probably going with a different system so thanks for the tip. I may use it.