Brake lights insensitive

[DKheld]

Argh - sorry to hear about that.

Practically the same thing happened to mine years back. Pressure switch failed in the on position. Melted the two green brake wires together and blew the fuse. Had to run new wires.

Eric

[djberson]

I caught it in time.... before blown fuses occurred or worse. What I didn't realize was that brake fluid dribbled out (how?) as I was driving it with wires unplugged and I realized the repercussions of this as I was backing up into a parking space in front of the parts store. My foot went to the floor and I went to pull the e-brake and instead opened my hood. Then smacked good and hard into the brick building to the astonishment of those inside.

[simplyconnected]

Brake fluid was coming out? Is this the original switch or did the fluid come out of a switch you changed?

First, you said your brake lights were not coming on. Now, they're coming on by themselves and melting connectors that are loose! What's up with all that?

There must be more to this story. Did you replace the switch? Did you seal the threads? Did you bleed the system? Wires don't simply fall off of brake switches.

[djberson]

The entire brake booster / master cylinder was replaced recently with an overhauled original system because there was some slapped together unidentifiable setup in the car when I got it with homemade parts and a cheap looking plastic master cylinder. The switch was put back on the car afterward and to my knowledge was working fine for a while. Then a motorist told me that they were working erratically, and sure enough a wire was loose when I looked. It seemed to me that they were working again when I reattached the wire, but only with considerable foot pressure until I removed the MC cap pumped the brakes a few times and tightened it back up. It is possible I was mistaken that it required too much pressure. It is very hard to check brake lights by oneself... I relied on a reflection of the lights off the car parked behind me. Nonetheless they were working (again, to my knowledge) just fine for a while when I noticed them stuck "on" today. By the way, I replaced the switch finally and it seems to be working fine. I think the leakage might have been from the plastic part of the switch melting. I wish I had not thrown it away already. I am already pricing new bumpers

[simplyconnected]

A fellow motorist pulled up next to me and mentioned my brake lights on my '60 were not working too well. So I opened the hood and found the wire connectors were loose, so I tightened them up. But I now realize that it takes a lot of foot pressure to get the brake lights to light up. That is fine for hard braking but in stop and go traffic I am afraid they may not be indicating brakes to the people behind me. Is there any way to adjust this?

Well, that makes more sense...
You see, all we can go by is what you write (whether it is correct, 50%, or not right at all). Then more information trickles in but it's in bits and pieces. This kind of description is very hard to help with from our end. If you can't borrow a foot to help while you inspect, then you don't really know what's happening under the hood.

You need to hire a good mechanic that will troubleshoot the system, check for plumbing and electrical connections, and generally make sure the car is safe to drive. It only takes one yo-yo to screw up, but don't blame the car.

If a repair job cost me a new bumper, you can bet that I would not foot the bill. Sounds like it's not the car that needs repair, but poor workmanship that someone performed. Your car should be solid as the day is long. All of these issues can be easily fixed. Too bad nobody pointed them out to you. Instead, they hid the weenie.


- Dave

[djberson]

I am definitely not blaming the car, but I am also in this case not blaming the mechanic. The work that was done with the brakes was many weeks ago. I suppose the wire connection could have been more secure, but things happen. Everything was fine for a while, the switch apparently just went bad. I was posting developments in real time which took several days to unfold which is why the information seems to be trickling in. I have been driving the car to and from work every day, 1/2 hour each way through city and on highway, and unfortunately today's events occurred as a result of the switch simply going bad on me. I only wish I changed it out a few days ago when I originally had suspicions about its performance, instead of waiting for today's disaster. I am writing all of this not only because I am hoping for advice from others who may have had a similar experience, but also to leave a record on this site for others who may find themselves in a similar predicament in the future.

[simplyconnected]

Brake work (in particular) is the very highest importance of all car functions. Your life depends on it. Brake work should not be measured in weeks, but in years.

You may work on your own brake system but a real mechanic must be certified by your state, to work on anyone's brake system. Serious legal consequences face non-certified people.

From post #3, you reconnected your Stop Light wires, and said they were tight. Then you said the master cylinder was changed after you got the car, and the Stop Switch was "put back on the car afterward and to my knowledge was working fine for a while." The operative here is, "to my knowledge."

Evidently, things were not right, regardless of whether you knew it or not. Thank God nobody got hurt from this failed brake job because I think you just avoided court appearances and a judgment.

Brake pressure switches are designed to safely pass ten amps. They can withstand 20amps upon short circuit conditions. The bad ones last a minimum of two years, while good ones last fifty or more. Not three weeks.

Every time the Stop Switch is removed, air enters the system. I asked if you sealed the threads and bled the system. I assumed you did the work because you said you had no help. The next we heard, your car crashed for failed brakes.

Again, I suggest you quickly hire a certified brake mechanic to go through your brake system, both the mechanical and electrical portions. He will guarantee his work and wires won't fall off.

We have posts of disasters from the past. Wolfgang in Germany had his car slip into reverse while a mechanic was under the hood tuning it. The car came to rest after backing over a wall. Then Wolfgang found out, the transmission was never overhauled after he paid for a major.

These aren't 'fingers of blame' but in each case, the situation could have been avoided IF properly trained skilled mechanics were employed.
- Dave

[Howard Prout]

As a result of this thread I remembered to check the brake lights on my car today - it turns out they were not working. A quick check revealed that the circuit was fine but was not being energized. I installed a new brake light switch and all was well again. I keep a new brake light switch in the glove box because the diaphragms in them tend to break down when exposed to DOT 5 brake fluid and you never know when you might need a new one. The good news is that they are cheap and readily available.

[Tbird1044]

I'll probably get mixed feedback on this one, but have any of you tried silicone brake fluid? I flushed my system about 15 years ago and refilled with silicone fluid and haven't touched it since. Just a thought and see what you guys think.

[djberson]

I am not sure what the advantage of running DOT5 is, but if it is actually harmful to the brake light sending unit, well.... that is not a selling point!

[simplyconnected]

I'm not big on DOT-5 either. DOT-3 is the fluid. It was back in the day and it still is. If there were a better fluid, auto companies would offer it.

Water still gets into all brake systems. In a DOT-5 system the water pools in the lowest areas which are usually inside wheel cylinders. Since silicone does not mix with water, the fluid will not turn colors.

I find silicone tends to give a spongy pedal because it compresses. Silicone is also a lot more expensive to buy. - Dave