The air pressure in a dual air brake system should build from 85 to 100 psi within:

When inspecting a vehicle with a dual air brake system, you should wait for air pressure to build from 85 to 100 psi in both the primary and secondary systems. This should take about 45 seconds.

% of our users get this question wrong.

This questions is relatively Easy.

Wait, before you go

Ace Your Texas CDL Written Test with our Guaranteed Cheat Sheet