Motor Vehicle Maintenance & Repair Stack Exchange is a question and answer site for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles. It only takes a minute to sign up.
Sign up to join this community
2003 Opel Agila
My brake lights do not light up until I have pushed the pedal down by about 1cm.
If I rest my foot on the brake pedal, with the brakes applied a little bit then the brake lights do not light up until I push down further.
This is obviously a safety issue.
What can I do to fix this?
Is it an easy fix?
EDIT: Is there a way to adjust and check the brake light switch?
Above the pedal should be a button, with 2 wires coming out of it. When your pedal is up, the button will be pressed all the way down, as you press the pedal, be button will release. At some point this button turns on your tail lights.
I know the one on my truck is adjustable (because I've had to adjust it). In this case, you remove the wires from the back and spin it to the proper location. You will want the sensor further from the pedal to have the lights come on earlier. Use a mirror or have a friend watch to ensure you have the proper adjustment and they do not stay on when you are not touching the pedal.
In the case the switch is not adjustable, you have 3 options. Replace the switch with a new one to see if it is any better. Modify the switch. This can be done in 2 ways - shave down the top of the button head so the plunger is further out, or open it up and clean/move/change the contacts. The third option is to modify the pedal or mounting. You may be able to bend the tab that hit the button's plunger, or the bracket the switch sits in.
I'm sure this is normal. There will be a little free play in the linkages to the master cylinder/ brake fluid compressing in the brake lines so the brakes will not be applying until you push the pedal further any way. It reduces the risk of your brake lights flickering while driving if pedal is bumped. But I am not a mechanic. I've driven truck for many years I do know what your talking about, I've noticed that myself, lights do not come on instantly.
It will be interesting to follow up. Good luck. In regards to the earlier answer. I would think you would need to bring the switch contact closer to the pedal to come on sooner.
In an adjustment to your brakes be sure to test your brakes many times before heading to the road. If the pedal bottoms out on the switch it may not allow the pedal to reach the vehicles stopping point.
I like the list of options presented by rpmerf in his answer. It's definitely something you can tackle if you have a couple of hours to spare.
Here's a hands-on approach to figure out what's going on:
Push the driver's seat back as far as it will go and put something like a tablecloth or newspaper in the footwell, since you will probably need to rest your head against it
Turn the key in the ignition to the 'On' state, so the car's electricals power up. There is no need to start the car for this.
In fact, the brake lights might be receiving power regardless of whether the car is on or off, so this step may not apply.
Use a torch (a head-mounted lamp works great here) to see the business end of the brake pedal. You should see the brake pedal switch as something that interacts with the brake pedal lever, which should look something like this:
The pop-button at the end is what controls whether the brake light switch is open or closed.
Once the brake light switch is located, you should be able to ascertain what is wrong with the switch:
Is it misaligned? If so, the way the switch is mounted may provide the ability to perform some adjustment by either lowering or raising the switch position. You may have to loosen a bolt or two to achieve this.
Is something sticking? Maybe the spring inside the switch is to blame. Maybe there is some crud that affects the switch's ability to pop out. Repair/replace as applicable.
I just had the same issue with the brake light not coming on until brake pedal is pressed some quarter way down. I often felt this was somewhat dangerous because even when I gently pressed the brakes no one behind me knew I was pressing it.
I decided to shave about a quarter of the part of the brake switch protruding out. Once done, gently pressing the brake pedal activated the brake light switch and turn on the brake lights.
It was a quick fix, and it worked.
