I have a 2007 Suburban LT with a Reese Pilot brake controller (Time delayed controller). The suburban was factory wired for the controller. There are times when I apply the brakes and the trailer brakes do not activate. I almost have to tap the brake and keep pressure on it to get the trailer brakes to activate. As far as I can tell the controller is installed properly. The brake lights on the trailer come on even if the trailer brakes aren't activating and the trailer brakes work manually with the controller.
Any thoughts on this?

 

There will always be a delay in that type of brake controller. There should be a sinc switch or some kind of adjustment for the delay, that might be your problem. If not you might want to upgrade to a propotional controller. This type is easier on your braking system. I know I have been really happy with my Prodigy P3, a little overkill but nice.