I had to replace my master cylinder and booster about 2 weeks aftert I bought the truck and now my brake lights don't come on nor do my trailor brakes engage unless I push the pedal firmly. When I am just barely using brakes( very light pressure or tapping) to come to a slow stop the lights don't come on nor do my trailor brakes engage. Could this be a issue with rod length in booster or adjustment of brake switch? I'm going camping tomorrow afternoon w/ kids for spring break and would like to get this taken care of before I go. Thanks for any help.

 

Is this a symptom of some dreadful failure about to happen? I have been told it was normal on Fords but I would like confirmation since I'll be towing my vintage Airstream w/ the family quite often. Thanks.

 

Since the brake lights, and from what I've seen - most trailer brakes, are electrically operated, suggest that the replacement of the brake parts altered the pedal operation somehow.

The rod length of the booster could be a contributing factor. Does the brake pedal travel seem to have changed, in that it doesn't go as far down as it used to? If the brakes themselves seem to operate fine, may be easier to adjust the appropriate switches for the brake lights and trailer brakes than it would be to go back in and adjust the rod.

As far as the rear end whine - not normal, at least not on the older model years that I'm most familiar with. Suggest to get this checked out, particularly if the characteristic or loudness of the whine has changed recently.

 

Most likely it's the switch under brake pedal assembly that is either going bad or needs adjusted so that it closes when pushing on the pedal. It's located right under the pedal and when you push on it the bracket or arm assembly (what ever you call it) closes the switch and you have lights. I'm guessing you might be able to adjust yours because you say the lights do work when you push on it hard.

 

Most likely is a brake switch adjustment problem since problem started after the other repairs were made,as far as the rear end noise,i just had to replace my pinion bearings for whine noise,also replaced carrier & axle bearings while i was in the differential anyway,no noise now.

 

Thanks guys, I will be working on these things. I replaced the brake light switch and i still have the same problem, i also adjusted the rod in brake booster, no help. I'm at a loss.

 

Is the brake switch closing when you apply the brakes, and the lights are just not coming on?

 

It appears that I have to press the pedal about 2 inches before the switch closes and the light comes on. It's either like that or I adjust the switch to far and it's on all the time, doesn't seem to be an in between.

 

Sounds like the switch is bad. It should adjust better than that.

 

It's a new switch. I'm starting to think I have some other issue.