ABS Brake failure scare!

Was pulling out of my favorite fuel service station in my '95 Chevy Beretta this morning. It has a slight decline and a right turn to take the exit to the street. As I started the decline turning right, I applied brakes to keep down speed in the station lot. Pedal bottomed out, no brakes! Started manual pumping to slow down, no brakes, no compression resistance! Car starting to accelerate with gear shift in drive, and engine just idling as I head for the busy street. Threw the gear shift into neutral and steered the car onto the grass between the street and the sidewalk. That procedure put me on the grass with a slight incline, and the car stopped after about 15 feet of travel on the grass.

Placed gear shift in park, checked my pants for wetness and/or odor, found neither.

I tried brake pedal and found I now had compression. I placed transmission shifter (Automatic transmission) in low gear and inched forward then applied brakes, they worked.

Kept car in low gear and rode home, approximately 1/2 mile using back streets and 7mph, brakes continued to work okay. Got home and checked the master brake reservoir and it was full. No leaks visible anywhere near brake lines. Compression resistance exists with engine on or off when I press the brake pedal.

What in blazes happened and how do I fix it? Checked for recall on Chevy Beretta ABS brake systems and found none.

Bountyhunter <img src="/images/graemlins/tongue.gif" alt="" /> <img src="/images/graemlins/tongue.gif" alt="" /> <img src="/images/graemlins/tongue.gif" alt="" /> <img src="/images/graemlins/crazy.gif" alt="" /> <img src="/images/graemlins/crazy.gif" alt="" /> <img src="/images/graemlins/crazy.gif" alt="" />

Normally an ABS failure won't affect the brakes unless you have the old Bendix system 10 (Chrysler used it in the early 90's, I don't know what system GM used at that time). Maybe try your recall search without ABS in the search text. Is there any chance the engine could have stalled or tried to stall and maybe sputtered a bit and started running again? A stall could give the same symptoms as the vacuum pressure for the power brakes went away (most people have never driven a vehicle without power brakes and will confuse loss of power brakes for a complete loss of brakes, though your pumping should have done something)

Your description indicates that the parachute (cup) seals inside of the master cylinder are bypassing, which means no pedal pressure at all. In the early stages of failure it works for a while then doesn't. When you pumped the brakes did you push in or did you kick it, hammering the brakes usually makes the seal flare and grab when just pushing in on the pedal won't do anything, but this doesn't always work. As long as the rear seal is intact the master cylinder will not leak out of the back.

And yes i have had this happen to me before, it really wakes you up doesn't it. Now i can't say for sure that the ABS is not the culprit but i don't think it is. Normally when the ABS faults you still have pedal pressure and brakes just no ABS. If i remember correctly the ABS on your car should just limit the pressure going to the wheels, if it really acts up the car won't stop well but you will still have pedal pressure but this is very rare. HTH

Did you try the parking brake by any chance? I know I was always taught if the brakes fail try to down shift and apply the parking brake. Never had to try it, but I wondered if that was/is the best route.

My uncle uses a bretta, I'll have to ask him if he had any problems with the breaks like that. He recently upgraded to what he refers to as "his mid-life crsis" car, a 2003 mustang. Very tight.

I've not experienced brake failure in a car only in a truck. When I say truck I mean 18 Tonne truck. Lost air pressure to the brakes so slowed down using the engine, crashing down through the gears is a good way to bring your speed down. In the UK on some inclines there are gravel beds just for such an occurance, but the're not everywhere, so you have to bleed off the speed best way you can, as you did by brushing the verge. I've not heard of this type of failure on "modern" cars ('95 is still modern when your last but one car was a '67 mini). <img src="/images/graemlins/grin.gif" alt="" />
I think you did it right, but it sure shakes your confidence.

I tried using the the handbreak from about 20 km/h in an empty parking lot (if you expect to use it in an emergency, you should try it first, shouldn´t you). It was a painfully long distance before the car stopped. Instead of the almost immediate stop with regular breaking it took about 15 m. The car was an old VW beetle. As the CG is pretty far aft, it stayed pretty stable. When I tried this with a more modern car, the rear brakes had the tendency to lock. That made the distance for stopping even longer. Most modern car have their CG to the front. That way the tend to understeer.
If you count on using that technique, you may wish to try it when you still have alternatives.

RayW:

I know the routine and regularly replace my own brakes. I have not done so on this junker as it is a throw away car that cost less than $300.00. This is the first ABS vehicle I have ever had. The pulsating has only rarely occured and only during wet weather, but it was nowhere near the pulsating speed I have heard ABS brakes are capable of.

I was pumping with no response in pressure as I rolled toward the exit. This has happened before in a different manner in that the brakes respond, but the car slips a little, while the brakes continue to hold.

This is the first time it has gone to the floor.

By the way, the ABS warning light has been on for almost a full year.

Bountyhunter <img src="/images/graemlins/crazy.gif" alt="" />

Paul810:

I am a big believer in parking brakes and use them regularly even on flat surfaces. Cars that are worth keeping for a while get new brakes when I buy them and parking brake cables are replaced and working. This one is a junker and most people do not use their parking brake, so this one has a frozen parking brake which I could not actuate.

Bountyhunter <img src="/images/graemlins/crazy.gif" alt="" />

Eugene:

I know about pressure and vacumn loss scenerios, but the engine was idling fine. I did the routine automatically with the pumping and only went after the transmission change when no effect was noticable.

Last time I had a complete brake failure even approaching this magnitude was in a 1965 Plymouth Valiant station wagon which at that time had only one line from the master cylinder supplying all four brakes. Developed a leak and lost all fluid and all brakes. I was lucky on that one also in that I was at stop light just starting to accelerate when I touched the brake for some reason and felt it go to the floor. That time I stopped with the parking brake which was hand operated. Drove home that time almost two miles with nothing but the hand brake.

Somebody up there is crazy about me or else they have been sleeping when it was time to collect me and take me home.

Bountyhunter <img src="/images/graemlins/crazy.gif" alt="" />

Bountyhunter, have you tried reading the codes to see if there is a code set for the ABS? On your car i think you can pull codes with a paper clip. Sorry i don't have my chevy shop manuals anymore so i don't have the information sitting in the garage anymore, don't know of any web sites right off hand. But that is where i would start.

And you are right ABS can be a pain, i wish it came with an off switch because there are times i want the dirt to push up in front of the tires.

RayW:

I have the code jumper key for GM's, but not the code manual.

Drove the car to buy lottery tickets yesterday, very slowly, and everything worked fine through multiple test stops. Did hard stops, slow stops, stops while turning, and stops while backing up straight and turning. No problems, power assist is online, and brake fluid is right up there.

Someone suggested collapsing seals in the master cylinder and I have a problem believing that, as once collapsed, they rarely come back for extended periods like the test stops I made yesterday.

Checked the master brake cylinder setup and the ABS is intregal with the master cylinder, so I imagine the replacement is going to be a nightmare if the master cylinder is the problem.

I want to check the computer code readout first, but even then, I find it hard to believe that an electronic sensor or control would cause the problem I had as electronic failures are supposed to default only to the extent of putting you in regular brake mode.

I'm going to talk to a Saturn service manager as I have found them to be more friendly to DIY's than regular Chevy dealers.

Bountyhunter <img src="/images/graemlins/crazy.gif" alt="" />

Bounty, you are right if the seals were worn it doesn't take many stops to repeat the problem of no brakes. Have you flushed the brake fluid lately, i'm really reaching, but if a particle of crud managed to get next to the seal you would have your problem. On some of the less properly maintained cars i have worked on an amazing amount of junk comes out of the lines when the fluid is flushed.

While we are on the subject, a dragging parking brake or a long downhill run with the brakes applied will cause the brakes to fail when the brake fluid starts to boil. And this didn't happen to your brakes Bountyhunter. If you find out what the problem is be sure you post it, i would like to know.