i drove my car on the highway with the emergency brake on--did i screw up my car?

[LTC8K6]

Really the only light that would come on if his master cylinder ran low or the ABS didn't pass the test the BCM puts it through upon startup.

Or the parking brake is on...

 

[pcgeek11]

This. It's quite elegant as it saves the need for a separate brake system as well. Also, it self-adjusts, unlike a separate parking brake mechanism which needs to be manually adjusted every few years.

The caveat is that it can only really be used on single-piston floating caliper disc brakes since multi-piston calipers would need each piston's mechanism to be carefully synchronized with each other piston's mechanism to avoid issues with the pads getting misaligned.

ZV

I have to disagree. Every car that I have owned has had a self adjustment star wheel in the rear drum brake mechanism. The only time that I have ever had to adjust the rear brake is when I replaced the shoes.

They work really well as long as you use the parking brake when you park or brake when in reverse.

 

[Wingznut]

Well at least it was only the emergency brake... Now if it was the parking brake on the other hand, then yes that would be bad. What kind of car has an emergency brake? Seems kinda nifty feature. Oh and no a Parking Brake is NOT an emergency brake.

^ Useless.

It's not useless because it's an incorrect description and people seemingly forget its intended purpose, that you're suppose to use it when you park! I've seen too many people who just use the parking pawl but do not use the parking brake! Maybe if people referred to its correct term, more people would use it...

The terms are interchangable. Don't believe me? Check out one of the many dictionaries.

dictionary.com reads:
emergency brake noun
1. Also called parking brake. a special brake used to prevent a motor vehicle from rolling after it has stopped or been parked.
2. any brake meant to stop a vehicle in an emergency.

Merriam-Webster reads:
emergency brake noun:
a special brake (such as a parking brake in an automobile) that can be used for stopping when the main brakes fail

And guess what... If you use either term with the overwhelming majority of human beings, they will know what you are talking about.

Get over it.

 

[Zenmervolt]

I have to disagree. Every car that I have owned has had a self adjustment star wheel in the rear drum brake mechanism. The only time that I have ever had to adjust the rear brake is when I replaced the shoes.

They work really well as long as you use the parking brake when you park or brake when in reverse.

The star wheel is for manual adjustment. It is absolutely not a self-adjuster.

Also, the "self-adjust when braking in reverse" only works when the rear service brake is a drum brake and the parking brake actuates the shoes of the service brake. The self-adjustment happens because the service brake self-adjusts when you brake in reverse and the parking brake is actuating the same shoes as the service brake. This only happens because the service brake and the parking brake actuate the same shoes.

If the service brake is a disc and the parking brake is a drum there is zero self-adjustment for the parking brake.

ZV

 

[Wingznut]

The star wheel is for manual adjustment. It is absolutely not a self-adjuster.

Actually, it can do both (depending on the design...) For instance, the Chevy setup pictured below. As the shoes expand, the adjuster pushes on the star wheel, and turns it a notch, if there is room. And since that wasn't altogether efficient, you could also pop out the little cover in the back and adjust the wheel manually.

 

[tortillasoup]

The terms are interchangable. Don't believe me? Check out one of the many dictionaries.

dictionary.com reads:
emergency brake noun
1. Also called parking brake. a special brake used to prevent a motor vehicle from rolling after it has stopped or been parked.
2. any brake meant to stop a vehicle in an emergency.

Merriam-Webster reads:
emergency brake noun:
a special brake (such as a parking brake in an automobile) that can be used for stopping when the main brakes fail

And guess what... If you use either term with the overwhelming majority of human beings, they will know what you are talking about.

Get over it.

Yes, you can see there are two definitions. Just because they list a definition to a word, it doesn't make it correct to use that term in a sentence. Calling a Parking Brake an Emergency Brake is very deceptive. To call a Parking Brake an Emergency Brake implies a lot of things that aren't true while at the same time ignoring its intended purpose. The people who author those dictionaries are only obligated to write in there what is used colloquially, in every day language. This is why dumb fucking words like "irregardless" have/will/are appearing in dictionaries now EVEN THOUGH IT'S WRONG.

Case in point:
http://www.merriam-webster.com/video/0037-irregardless.html

 

[Wingznut]

But it is also an emergency brake. It is a mechanical brake which can be used in the event of a hydraulic failure.

So, either term works to describe the mechanism.

 

[tortillasoup]

But it is also an emergency brake. It is a mechanical brake which can be used in the event of a hydraulic failure.

So, either term works to describe the mechanism.

Didn't this thread basically prove that this isn't always the case? Also the braking power of these brakes is a complete joke, especially like in the case of the Floor Mat Recall for Toyotas when you have a stuck accelerator. If you had a run away vehicle situation like going down a hill, your bakes failed and whatnot, if you tried using the parking braking, it likely wouldn't do shit.

 

[Zenmervolt]

Actually, it can do both (depending on the design...) For instance, the Chevy setup pictured below. As the shoes expand, the adjuster pushes on the star wheel, and turns it a notch, if there is room. And since that wasn't altogether efficient, you could also pop out the little cover in the back and adjust the wheel manually.

Nifty! Hadn't come across something like that. The Euro cars I've seen with separate drum parking brakes are strictly manual adjustment, which can be a minor annoyance after a few years. Of course, cable stretch is a bigger issue and almost no-one ever bothers to adjust that.

ZV

 

[pcgeek11]

The star wheel is for manual adjustment. It is absolutely not a self-adjuster.

Also, the "self-adjust when braking in reverse" only works when the rear service brake is a drum brake and the parking brake actuates the shoes of the service brake. The self-adjustment happens because the service brake self-adjusts when you brake in reverse and the parking brake is actuating the same shoes as the service brake. This only happens because the service brake and the parking brake actuate the same shoes.

If the service brake is a disc and the parking brake is a drum there is zero self-adjustment for the parking brake.

ZV

Incorrect. The star wheel is part of the automatic adjustment along with the lever that actuates it.

http://auto.howstuffworks.com/auto-parts/brakes/brake-types/drum-brake2.htm

 

[Zenmervolt]

Incorrect. The star wheel is part of the automatic adjustment along with the lever that actuates it.

http://auto.howstuffworks.com/auto-parts/brakes/brake-types/drum-brake2.htm

I've never seen one of those on a separate, parking-brake-only drum. They've had the star wheel, but no lever. It's the lever that's the self-adjuster. The star wheel is simply a part that exists even in non-self-adjusting mechanisms (where it is used to make manual adjustments).

Also, you're just repeating what Wingznut already posted.

ZV

 

[Wingznut]

I've never seen one of those on a separate, parking-brake-only drum. They've had the star wheel, but no lever. It's the lever that's the self-adjuster. The star wheel is simply a part that exists even in non-self-adjusting mechanisms (where it is used to make manual adjustments).

Also, you're just repeating what Wingznut already posted.

ZV

Yeah, I've never seen that setup on a parking-brake-only drum, either. (I used to be a professional mechanic, too...)

I'm not even sure any car with made in the last decade or two still uses that system that I pictured.

 

[_Rick_]

Didn't this thread basically prove that this isn't always the case? Also the braking power of these brakes is a complete joke, especially like in the case of the Floor Mat Recall for Toyotas when you have a stuck accelerator. If you had a run away vehicle situation like going down a hill, your bakes failed and whatnot, if you tried using the parking braking, it likely wouldn't do shit.

The actuation is independent, the braking hardware (pads/calipers/disks/drums) itself may or may not be independent.
But the parking brake is usually actuated directly by the pulley, and not hydraulically, so yes, if hydraulics fail, you can use it as a backup.
Yet it only brakes the rear wheels which is usually not conducive to stopping from speed (even if it's linked to main calipers) and may introduce instability. Better than no brakes, still.
Also, many cars with auto boxes (which are essentially what makes a stuck accelerator/runaway engine really dangerous) have electrically actuated holding/parking brakes. Whether these will engage with a fully open throttle and above a certain speed isn't clear to me.

 

[pcgeek11]

I've never seen one of those on a separate, parking-brake-only drum. They've had the star wheel, but no lever. It's the lever that's the self-adjuster. The star wheel is simply a part that exists even in non-self-adjusting mechanisms (where it is used to make manual adjustments).

Also, you're just repeating what Wingznut already posted.

ZV

I'll just say that the automatic " star wheel / lever system " has been on every American / Japanese car / truck that I have ever worked on with rear drum brakes. I'm not saying I've seen it all, but I've been working on my own cars since I was 15 and I'm 59 now... Granted I haven't worked on many European Cars as I have never owned any ( I think they suck for the most part ). So I am not just repeating what wingnut said. It is also what I said earlier just not as much detail.

I also do not know about the stand alone drum parking brakes with disc brake rears so ...

My truck is a 2012 with drum brakes in the rear with automatic adjustment. It used to be the norm even in the early 1960s cars. So yes they do still use it.

 

[Zenmervolt]

I also do not know about the stand alone drum parking brakes with disc brake rears so ...

But those are what we're talking about. And only those.

My truck is a 2012 with drum brakes in the rear with automatic adjustment. It used to be the norm even in the early 1960s cars. So yes they do still use it.

And, had you read what I've written, you'd have noticed that I already said that drum brakes used as service brakes do have automatic adjusters. I explicitly said that only the separate parking-brake-only drum systems lacked automatic adjustment. So what you've just posted doesn't contradict a damn thing I said.

ZV

 

[pcgeek11]

But those are what we're talking about. And only those.



And, had you read what I've written, you'd have noticed that I already said that drum brakes used as service brakes do have automatic adjusters. I explicitly said that only the separate parking-brake-only drum systems lacked automatic adjustment. So what you've just posted doesn't contradict a damn thing I said.

ZV

Would you feel better if I said that you win?

 

[Zenmervolt]

Would you feel better if I said that you win?

It's not about winning, it's about the amount of confusion and side-tracking caused because you weren't clear.

The conversation went like this:

Me: The parking brakes that use the service brake's pads are self-adjusting, but the ones that use a separate, parking brake only drum instead of the service brake's pads are not.

You: They are self-adjusting because they have a star wheel.

Me: The star wheel is not the self-adjuster.

Wingz: The self-adjuster actuates the star wheel, as on this example of a GM rear drum service brake.

Me: Nifty.

You: The self-adjuster actuates the star wheel.

Me: You're repeating what Wingz said.

You: No I'm not. Also, self-adjusters are on all service brakes. I don't know anything about the separate, parking brake only drums used when the rear service brake is a disc though.

Me: We've never been talking about anything other than the separate, parking brake only drums used when the rear service brake is a disc. Those brakes don't have self-adjusters.
----------------

Can you see why that might be annoying?

ZV

 

[MongGrel]

But it is also an emergency brake. It is a mechanical brake which can be used in the event of a hydraulic failure.

So, either term works to describe the mechanism.

Seriously, this one is just splitting hairs.

Like he said, what do you do if the hydraulics fail?

The redundant brake, I never use it when parking myself.

Why not just call it that the Redundancy Brake, kidding a bit.

 

[phucheneh]

Wow, you guys are arguing over some dumb shit.

'Parking brake!' 'Emergency brake!'

Both.

'E-brake in caliper!' 'E-brake in seperate drum!'

Both.

'Self-adjusts!' 'Does not self-adjust!'

...wait for it...

Both.

Although technically, I think ZV is right in that seperate drums on a rear disc car never have an auto-adjuster. Not that auto-adjusters ever work worth a damn on rear drum cars, anyway.

But it's a moot point, as the e-brake shoes practically don't wear at all if used for their intended purpose. I.e. holding the car still with static friction. And yes, I will cite that as the primary purpose while still calling it an 'e-brake' because it's the shortest way to say it and I frankly couldn't give two shits.

 

[tortillasoup]

Wow, you guys are arguing over some dumb shit.

'Parking brake!' 'Emergency brake!'

Both.

'E-brake in caliper!' 'E-brake in seperate drum!'

Both.

'Self-adjusts!' 'Does not self-adjust!'

...wait for it...

Both.

Although technically, I think ZV is right in that seperate drums on a rear disc car never have an auto-adjuster. Not that auto-adjusters ever work worth a damn on rear drum cars, anyway.

But it's a moot point, as the e-brake shoes practically don't wear at all if used for their intended purpose. I.e. holding the car still with static friction. And yes, I will cite that as the primary purpose while still calling it an 'e-brake' because it's the shortest way to say it and I frankly couldn't give two shits.

why not P-brake? same thing

 

[Zenmervolt]

Wow, you guys are arguing over some dumb shit.

Welcome to the internet. :biggrin:

But it's a moot point, as the e-brake shoes practically don't wear at all if used for their intended purpose.

They do seem to come out of adjustment over time though. When I replaced the rear rotors on my S70 the little drum parking brake had to be re-adjusted because apparently the inner diameter of the integrated drum was ever so slightly different on the new rotors. I had to do the same with my 951 a while back because the lever started being able to come up too far, which flipped the little ratchet mechanism and started making the lever refuse to release. (Yes, I took up the slack in the cable too, but the shoes were also out of adjustment.)

It really is amazing how many people don't bother to take care of their parking brake. Though, given that I've seen people using 12-volt batteries from uninterruptible power supplies (held down with a makeshift rope made of old socks) instead of car batteries I guess I shouldn't be surprised.

ZV

 

[Brianne Shomate]

So I'm worried myself about leaving my emergency brake on while driving. My excuse is way more heavy. My uncle more of a father figure passed away yesterday from stage four cancer. I went to the store to buy smokes. While I was there my husband on the phone started yelling at me at the top of his lungs so loud that I could barely hear what he was saying, then I yelled back in the mist of all of that and hurt my throat from yelling at him. Went into the store bought my smokes came back out. Lit up a smoke on the spot. Then drove away with the brake on. The light was on, on the dash but I was so pissed off I was only focused on the road and it being night time with tons of deer, that all kept me more occupied then paying attention to the light on my dash. I got back to the house after driving 13 miles and when I stopped to back up, I then noticed the brake was on. I quickly pulled the brake release. Then quickly backed into my driveway to notice one the smell, and two the smoke. I got underneath the truck to take a look. I didn't see any noticable damage but redacted it was hot. Did I fuck up my shit? It a 1998 Dodge Cummins. I just replaced the front brakes just a few days ago. If my husband didn't get me so worked up I probably would have noticed the brake on and turned it off. I'm thinking because it drove pretty easy that it wasn't in all the way. Like I said I didn't see any noticable damage, but the smoke and smell and heat was pretty clear so, did I just rub a little wear on my brakes?



No profanity in the Garage.


esquared
Anandtech Forum Director