# Brakes locking



## 03glgold (Jan 26, 2016)

So the other night I was driving back to Hays from the Wichita area and a deer ran out a little bit in front of me. I hit the brakes with medium force and they locked up briefly before I let off. Even though slowing down was important, I had to let off when I did because in the second or so that the brakes were applied the rear end started to come around. I have thought that the abs has felt a little bit off in the snow, but wasn't certain because I am not too accustomed to driving with abs. It took about a quarter to a third of the pedal force that it took to lock the brakes on my alero that didn't have abs. My question is if it is normal for it to be able to lock that heavily before abs kicks in. It never showed any abs lights. I waited to post until I got a chance to search and didn't find anything. It is something I can deal with, as I am used to no abs, it just caught me by surprise when they locked. I need to know if there is some sort of problem I need to be looking out for though.


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## Eddy Cruze (Jan 10, 2014)

You probably shouldn't have let off on the brake pedal, however there is always a chance your ABS is not working properly. Here is some good reading on ABS

https://en.wikipedia.org/wiki/Anti-lock_braking_system


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## obermd (Mar 3, 2012)

Which trim Cruze do you have? This sounds to me like the rear brakes aren't adjusted properly. Did you actually leave skid marks or was it just the rear end trying to come around on you?


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## NickD (Dec 10, 2011)

Had vehicles with ABS for over 35 years now, personally I do not like them, more problems than what they are worth, and if on glare ice, nothing works.

But even on older GM vehicles were far superior to these super cheap Bosch ABS brakes used on the Cruze. They would pulse at least one or two times per second and sounds like the front end is going to fall off. Where on the older much better ones, would pulse about ten times per second.

Nothing on the shop manual on this subject, and talking with several Chevy dealers, tell me this is normal, like a major clunk, wait a bit another clunk sound. The period they hold the faster spinning wheel locked is way in the hail too long.

Should be a recall on these, if they are normal, a very poor design. Driving on icy roads, very careful not to hit the brake pedal hard enough so the ABS will not engage, but no choice if some idiot or a deer pulls out in front of you.

And screw you A$$hole congress that made these law, and the idiots that designed them, don't stop the car any quicker, and if that locked wheel hits a solid surface will put Cruze into a skid.

Yet another problem with disc brakes are those cast iron pad holders with metal clips on them, a natural trap for road salt that forms rust expanding the clips that locks the pads in the stopped position. The pads stay in this locked position, do require frequent cleaning and sure help to put a heavy coating of anti-seize under those clips.

Toyota came out with these in the mid-80's, was a stupid ideal so they got away from these cast iron pad holders and clips, but some idiot at Chevy copied these. Not nearly the problem in salt free country.

With rear brake drums, the return springs are way too weak, so if the shoes are not perfectly free to move and self center, the rear adjusters will not work, in particular the anchors at the bottom, again another good cleaning and anti-seize helps, but still require constant maintenance.

I don't have this problem with the 2LT has four wheel disc brakes, so have that metal clip on cast iron problem with trapped rust locking the pads in the stopped position. But also problems with the ratcheting adjusters rusting up, again exposed to road salt. But constant maintenance helps to resolve these issues.

Even back then, Consumers Reports had a lot of complaints about Toyota's brakes, but they didn't know why.


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## NickD (Dec 10, 2011)

Here is the kind of ABS hydraulic unit GM was using for years.










Large heavy unit.

And had a large separate ABS control unit.











This is the hydraulic unit for the Cruze.










That fits on this piece of plastic hydraulic unit.










Entire assembly will fit you your jacket pocket, then they have the nerve to charge 600 bucks for this POS. That ABS pump is what you would expect to see on a toy car.

Can't for the life me how they got this approved.


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## spacedout (Dec 7, 2010)

First snow I get with a new car I take it out and test out how the ABS, traction control and stability control systems work. 

You should have stayed on the pedal with similar pressure, that locking you felt is normal just before the ABS engages. Typically this locking will only occur with tires that have a hard compound, poor tread design for the conditions, or a tire that has little tread left. You can also notice this initial locking more when there is snow/ice on the road. 

The stability control system would have kicked in if the rear end of the car were to come around enough when on the brakes hard. From my testing its less than 1ft out in the rear before the stabilitrac takes over.


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## 03glgold (Jan 26, 2016)

Eddy Cruze said:


> You probably shouldn't have let off on the brake pedal, however there is always a chance your ABS is not working properly. Here is some good reading on ABS
> 
> https://en.wikipedia.org/wiki/Anti-lock_braking_system


I normally would have held a bit longer, but I had to square the car up in case there was another deer behind it. I could have pulled it out of worse, but if I would have hit a deer with the car partially sideways it could have had some particularly bad results.



obermd said:


> Which trim Cruze do you have? This sounds to me like the rear brakes aren't adjusted properly. Did you actually leave skid marks or was it just the rear end trying to come around on you?


It is a 1LT so yes it has rear drums and I had thought about that with the rear trying to come around. While I didn't stop to look for marks, you could hear the squeal of the tires sliding across the pavement.



NickD said:


> Had vehicles with ABS for over 35 years now, personally I do not like them, more problems than what they are worth, and if on glare ice, nothing works.
> 
> But even on older GM vehicles were far superior to these super cheap Bosch ABS brakes used on the Cruze. They would pulse at least one or two times per second and sounds like the front end is going to fall off. Where on the older much better ones, would pulse about ten times per second.
> 
> ...


I hear you on hating abs. One of my dad's trucks is a 97' Chevy 3500 that you have to down shift almost to a stop in slippery conditions. Abs has been worked on and is better than it used to be, but it still has a tendency to kick out the brakes and never lock back in on occasion. In my Alero without abs I had a feel for maximum braking pressure before the lock and think that I could stop a lot faster that way as compared to ones I drove that had abs. If it was slick it wasn't very hard to pump the pedal.


spacedout said:


> First snow I get with a new car I take it out and test out how the ABS, traction control and stability control systems work.
> 
> You should have stayed on the pedal with similar pressure, that locking you felt is normal just before the ABS engages. Typically this locking will only occur with tires that have a hard compound, poor tread design for the conditions, or a tire that has little tread left. You can also notice this initial locking more when there is snow/ice on the road.
> 
> The stability control system would have kicked in if the rear end of the car were to come around enough when on the brakes hard. From my testing its less than 1ft out in the rear before the stabilitrac takes over.


It was dry pavement and the tires have almost full tread. It was about 2-2.5 ft out and nothing had kicked in. I had to abort before there were real problems. I was more willing to end up hitting a deer heading straight forward than sliding sideways.


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## 03glgold (Jan 26, 2016)

Thank you to all who have replied.


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## jblackburn (Apr 14, 2012)

I've driven cars with ABS that squeal the tires when coming to a hard stop, but my Cruze just makes a whole lot of chuttering from the ABS - never heard the tires squeal when stomping on the pedal.


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## jmlo96 (May 2, 2015)

Something to take into consideration that I have noticed mostly on Hondas is that if all 4 wheels lock at the same time (say on a slick road), I'm not so sure ABS would even come on. All ABS does is monitor the speeds of each individual wheel. So if you figure that all 4 wheels at the same time go down to zero, the computer has no idea that wheels are locked. Thus, no ABS would turn on.


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## jblackburn (Apr 14, 2012)

jmlo96 said:


> Something to take into consideration that I have noticed mostly on Hondas is that if all 4 wheels lock at the same time (say on a slick road), I'm not so sure ABS would even come on. All ABS does is monitor the speeds of each individual wheel. So if you figure that all 4 wheels at the same time go down to zero, the computer has no idea that wheels are locked. Thus, no ABS would turn on.


I've done this on icy roads. Fun times.


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## pandrad61 (Jul 8, 2015)

jmlo96 said:


> Something to take into consideration that I have noticed mostly on Hondas is that if all 4 wheels lock at the same time (say on a slick road), I'm not so sure ABS would even come on. All ABS does is monitor the speeds of each individual wheel. So if you figure that all 4 wheels at the same time go down to zero, the computer has no idea that wheels are locked. Thus, no ABS would turn on.


Im sorry but you are mistaken. the computer watches each wheel speed censor and coordinates it with the transmission rpms. if it reads one wheel is locked for x speed it acts accordingly. if they all 4 lock then it will relief pressure on all 4. ABS does not simply watch and do nothing " All ABS does is monitor the speeds of each individual wheel" it monitors and adjust for the locking of the wheel


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## jmlo96 (May 2, 2015)

I'm sorry but I have to politely disagree. Jblackburn and I have both just noted instances of wheels locking up with ABS brakes. The theory of monitoring the RPM's of the transmission makes some sense, except what if the car is in neutral? That would mean a part of the ABS system was disabled and I am sure that's not the case. Especially when you have a manual transmission, no computer is monitoring the transmission. Here is a reference to a Wikipedia article on ABS. Specifically the "Operation" section states how ABS works. https://en.wikipedia.org/wiki/Anti-lock_braking_system


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## pandrad61 (Jul 8, 2015)

> blackburn and I have both just noted instances of wheels locking up with ABS brakes


from what i understand about your statement your saying the abs simply just watches the wheels and does nothing, that in ice it simply lets all 4 lock and it just stays locked or did i miss understand? I can understand if it does it for a second then acts but to stay locked up untill a crash/ let off of the brake/ or a stop does not sound right at all. now if you say it locks initially then unlocks i agree because my jeep 2 channel abs does the same. locks then it kicks in



> except what if the car is in neutral?


if your driving in neutral on icy roads you have more issues on hand then the abs. you never never free wheel when driving on less then optimal road surfaces, the new jeeps for example have a tranny speed and a t case senor and independent wheel senors. when in icy conditions with dad in a pick up when you put it to the floor the abs will simply not work right. it will pulse indefinably rather then locking up. when on super icy roads you want the wheels to lock up if you make them do so.

i may have misunderstood your comment, can you please clarify


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## jblackburn (Apr 14, 2012)

FWIW, my experience with it was from a 1998 Volvo, with a ABS system that was designed in 1993 or so. When sliding (sideways) on an icy road, all 4 wheels were locked at under 10 MPH. The car can sense, usually at higher speeds, if individual wheels are slipping, but if they're all sliding and locked, how is the car to know it isn't stopped? The rest of the time, the system worked great, snow or otherwise.

They're probably more sophisticated these days with yaw sensors and the like, but this wasn't. That said, the system worked tons better than that on a 2007 Honda.

BTW, watch videos of people sliding down icy hills with all 4 wheels locked. Should be some on Youtube.


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## ChevyGuy (Dec 13, 2014)

pandrad61 said:


> if they all 4 lock then it will relief pressure on all 4. ABS does not simply watch and do nothing


How would the ABS know the difference between all 4 locked and a stopped car? The car doesn't have eyeballs to see that's happening.

There may be something where it watches how fast the wheels stop. Probably works well for a lockup at 60 MPH. But I'm sure that still has limits - such as lockup at slow speed, or a slide that starts with slipping and progressing to lockup. Whatever, it's not foolproof.


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## obermd (Mar 3, 2012)

pandrad61 said:


> if your driving in neutral on icy roads you have more issues on hand then the abs. you never never free wheel when driving on less then optimal road surfaces, the new jeeps for example have a tranny speed and a t case senor and independent wheel senors. when in icy conditions with dad in a pick up when you put it to the floor the abs will simply not work right. it will pulse indefinably rather then locking up. when on super icy roads you want the wheels to lock up if you make them do so.
> 
> i may have misunderstood your comment, can you please clarify


Freewheeling is the last resort to recover from an all wheel slide. I have free wheeled out of slides on multiple occasions.


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## pandrad61 (Jul 8, 2015)

ChevyGuy said:


> How would the ABS know the difference between all 4 locked and a stopped car? The car doesn't have eyeballs to see that's happening.
> 
> There may be something where it watches how fast the wheels stop. Probably works well for a lockup at 60 MPH. But I'm sure that still has limits - such as lockup at slow speed, or a slide that starts with slipping and progressing to lockup. Whatever, it's not foolproof.


because the vehicle has the tranny speed sensor tied into the abs like the 4 wheel sensors. if the trans says, im doing 55mph but all 4 wheels say im locked up it acts accordingly.

now i do agree 100% that the system does have its flaws and is in the end a machine. im sure cheaper system dont detect as much. the new wranglers from what the jepe club tells me senses your in sand or slippery terrain and allows you to lock the wheels since sand you want to lock them up. the system is smart enough to detect it. this is also a 40k car vs the cruze econo box.


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## pandrad61 (Jul 8, 2015)

> Freewheeling is the last resort to recover from an all wheel slide. I have free wheeled out of slides on multiple occasions.


ive never heard of that but i didnt live in snow long enough to hear about super in depth ice driving recovery techniques


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## obermd (Mar 3, 2012)

pandrad61 said:


> ive never heard of that but i didnt live in snow long enough to hear about super in depth ice driving recovery techniques


It's actually a real simple concept. If you're sliding it's because there's insufficient friction between the tire and the ground (ice) to overcome the friction inherit in the transmission's connection to the drive wheel(s). Clutch in or throw the shifter to neutral eliminates the competing friction demands on the wheel so only the small amount of friction that exists between the sliding wheel and the ground will then become the dominate force impacting the wheel spin. 100% counter intuitive until you've experienced it though.


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## jblackburn (Apr 14, 2012)

^Same reason you don't try to decelerate significantly on slippery surfaces with gearing/engine braking like you would on a dry road. Your drive wheels aren't going to be spinning anymore.


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## pandrad61 (Jul 8, 2015)

Huh, you learn something new every day. ill keep that in mind when im up north for the next vacation.


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## ChevyGuy (Dec 13, 2014)

pandrad61 said:


> because the vehicle has the tranny speed sensor tied into the abs like the 4 wheel sensors. if the trans says, im doing 55mph but all 4 wheels say im locked up it acts accordingly.


Uhhhh, if all 4 wheels are locked up, how is the tranny speed sensor going to show anything other than stopped? Unless you've got a broken driveline, the output axle is stopped as well. If the speed sensor is still running, then at least one drive wheel still has to be turning.


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## 03glgold (Jan 26, 2016)

I have read through the comments and think that it could have had to do with the whole clutch depressed thing. I have always hit clutch pedal and brake pedal at about the same time. Every other time I have done it in this the abs has still activated though just felt weird which was explained by the different pulse rate from most. While I could see the clutch thing being a possibility, I would still think that the speedometer going from 70-0 should trip something with the computer. I was going 70 and when I had to let off because of the skid glanced down for lights and got to see the speedometer jump from 0-52 as soon as I released the pedal. I am not completely sure I understand the reason it could pick up with the same actions in snow, but I think that for now I will go with the possibility of a fluke and just be glad that in previous vehicles I spent a lot of time on gravel practicing skid recovery so I know what to do if stuff decides not to work right.


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## boneheaddoctor (Dec 10, 2014)

pandrad61 said:


> because the vehicle has the tranny speed sensor tied into the abs like the 4 wheel sensors.* if the trans says, im doing 55mph but all 4 wheels say im locked up it acts accordingly*.


I know that was said in error but.....

If that ever happens you have broken axles, differential or driveshaft. Otherwise your transmission would be showing 0mph when all four wheels were locked.


Edit...I see ChevyGuy beat me to it


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## BradSt (May 2, 2013)

I have felt the rear slide out a bit in a quick stop as well, but it won't come around...it just feels like it. The braking system is much more advanced than the early ABS systems, and to say that the older systems were better is laughable. The computer processing power required to do what the new Stabilitrac systems do, wasn't even available, in the earliest systems from the 90s.

Most modern stability control systems will detect that you are attempting a quick "panic" stop. When it senses this, it will actually apply the brakes to 100%, even if you're not calling for it. This will usually cause the tires to come close to locking (which causes the above sensation), which is where maximum braking effort takes place. Studies have shown that most drivers do not apply enough braking effort in these situations, and some accidents can be avoided by taking this action. Some GM owners manuals talk about this. Can't remember if the Cruze has this listed, but it does have the feature.

Also, if all 4 wheels lock at the same time, the system is smart enough to know that all 4 wheels are indeed skidding. Don't forget, the stability system also has yaw sensors, that are still reporting lateral G loads, which would be impossible if the vehicle were stopped. You can't fool the system. ABS and Stabilitrac deactivate around 5mph, so you can lock the wheels at speeds below this, however.

Also, it is almost impossible to lock all 4 tires at the same time, when using the same frame of reference the stability control system does...it reads in milliseconds...the small differences in lock times tell what is really happening


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## 03glgold (Jan 26, 2016)

The tires were definitely locked. Close to locked might give a very light sound, not the same heavy squeal. It was squealing quite a bit when it did it. It had come around far enough that I had to counter steer and at that point the system wasn't doing anything or the traction control/stability control low traction light would have been flashing and it did nothing. As I said before it might have been a fluke occurrence, but neither of the systems responded to the situation. If the system had been doing what it was supposed to and they were locking like that it would be a totally different problem. If you were to hold it long term you could end up with a flat spot (at least flatter spot) that could cause extra vibrations putting unnecessary wear on the bearings. Having said that it is better than the alternative issues people have had with the braking system on some of these cars where they hit the pedal and nothing to very little happens.


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## ChevyGuy (Dec 13, 2014)

BradSt said:


> Most modern stability control systems will detect that you are attempting a quick "panic" stop. When it senses this, it will actually apply the brakes to 100%, even if you're not calling for it. This will usually cause the tires to come close to locking (which causes the above sensation), which is where maximum braking effort takes place. Studies have shown that most drivers do not apply enough braking effort in these situations, and some accidents can be avoided by taking this action. Some GM owners manuals talk about this. Can't remember if the Cruze has this listed, but it does have the feature.


The 2013 owner's manual calls it "Brake Assist" (page 9-33).


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## pandrad61 (Jul 8, 2015)

> If that ever happens you have broken axles, differential or driveshaft. Otherwise your transmission would be showing 0mph when all four wheels were locked.


then how did non abs cars of the past that would very often lock up all 4 not have a broken drive line?

modern abs units get speed readings from trans, t case if applicable and 4 wheel and most new cars has an accelerometer and as *BradSt* said yaw meter. modern abs units know your car is moving and what its doing at all times. now this is where i can see abs having issues, when its black ice is present and no matter how much pressure the system bleeds off it will not have grip to stop locking. i could see the abs in that scenario default locking the wheels vs endless pulsing to no avail


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