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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?

  • 1
    Might be a brake light switch issue. – Max Goodridge Feb 10 '16 at 20:56
  • 2
    I'm wondering if there is an adjustment for the brake light switch, something where you can adjust the contact depth on the pedal? If pushed a little further away from the pedal, it will come on sooner. – Pᴀᴜʟsᴛᴇʀ2 Feb 10 '16 at 22:13
  • Why is this a safety issue? Does 8mm basically lock the wheels? If at 10mm you're slightly slowing down, whoopdie-doo. Vehicles slow down slightly all the time on the road without hitting their brakes. – Zach Mierzejewski Feb 11 '16 at 1:44
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    I understand what you are saying @George. I like to tap my brake sometimes on the freeway to flash my lights at tailgaters. I do this frequently to get them to back off. This problem would bother me. – Ppoggio Feb 11 '16 at 10:38
  • 1
    @ZachMierzejewski It's a safety issue. Grow up. – Ppoggio Feb 11 '16 at 10:39
4

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.

  • Sound advice here. – Zaid Feb 12 '16 at 13:56
  • I think adjusting the switch by shaving it up may not be a good solution, you may end up with permanently on brake lights. The real question is what is the correct tolerance for this switch. In my opinion, 5mm pressing of the pedal will not engage the brakes at significant force (at least no car I have driven was so sensitive) so there is no point for the light to come on. – Evren Yurtesen Mar 15 '17 at 9:57
2

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.

2

It definitely sounds like your brake light switch isn't activating when it should.

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:

    Brake pedal switch

    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.

0

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.

  • One issue you may cause is the brake lights flashing as you go over bumps... REALLY annoying for other road users so, in terms of the safety you mention, that should be a consideration... – Solar Mike Jan 19 at 9:59

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