Just guessing but it could be the combination valve. because it has the metering valve within it. The metering valve is supposed to hold off pressure going from the master cylinder to the front calipers until enough pressure builds up in the rear drums., so that your front brakes don't "operate" until the rear brakes have started to operate.

 

That does sound like the combination valve could be the culprit. If the ABS light is on, I'd also suspect a component fault (the light is on for a reason, a fault was detected. When the ABS light is on, correct me if I'm wrong, the ABS is non-functional. So when you're stopping, the rear wheels likely are locking up.

 

From the sounds of it I would say that you have an ABS failure that it causing one of the front tires to free-wheel while the other goes to full braking power.

What you have described as happening only happens when one side of an axle's brakes are working. Dirt racers remove the passenger side brake caliper to get the cars to rotate quicker into the corners, just like what you learned.

 

The problem is almost certainly your ABS system. The fact that the back end is swinging out means that the rear axle is over braked. If the front wheels were braking too much the vehicle would just understeer and go straight ahead. Most modern cars have no combo valve or proportioning valve anymore. Instead the abs has a function called Dynamic Rear Proportioning (DRP). This automatically limits the rear brake pressure based on the slip difference between the front and rear axles. A mechanical prop valve is typically optimized for the worst case which is a lightly loaded condition and you end up with longer stopping distances when the vehicle is loaded.

DRP can adjust for loading differences because the front/rear slip balance changes and can be detected by the system allowing for shorter stopping distances under loaded conditions. The fact that your ABS light is on means the DRP is probably not functioning properly. Most likely you have one or more bad wheel speed sensors. This would result in the behavior you describe and it will tend to be worse under slippery conditions. I would take it in and get the abs fixed as soon as possible.

 

Well I have the same problem as you with the sensor just my rear end doesn't kick out I've replaced Fuel Pump and 3 Left hub assembles and when I press the breaks in the snow my breaks lock up and my break pedal pushes back at you and my car makes a horrible sound?!? And I have no idea what's going and and local mechanics do not know what it is any ideas???

 

I would say your rear drums are out of adjustment, and you need to make sure your tires are all set to the proper PSI, then I would probably rotate the tires. you want the better ones in the back, believe it or not - actually to assist in keeping the ass from coming around. traction up front is only good to a point, the rear is too light on a FWD car, you need better tires in rear.

aside from that, if the ABS system is inoperative, which it is - because you have the ABS lamp illuminated, you need to fix that. what I think is happening, is that the rear end is locking up - probably because the drums are out of adjustment, and because of the ABS being inoperative.

We dont normally see any issues with the BPMV to cause this problem. the car does not have a dynamic rear proportioning valve. its not a ford.

Other problems you may have - worn suspension component - be it a broken rear spring, or something loose or worn out, or you could actually have a problem with the wheel cylinder. this can cause an issue because if one side applies differently from the other, it will make the rear of the car sway due to uneven braking. also you could have a brake lining that is saturated in brake fluid - like from a leaking wheel cylinder or other contaminant on the rear drum, so it can create an issue with coefficient of friction, which will create uneven braking in the rear.

and if all that check out, then I would check the hydraulic system for adequate flow to each wheel.

You may also have a broken brake line, and the system may have sealed off a section of the braking system, with the pressure differential valve. this probably is not the case, unless you have the red BRAKE warning light illuminated.

Hope this helps.

Edit - You do not have a sensor issue that is creating the rear to swing out. The wheel speed sensor signals become useless when the ABS lamp is on, since the ABS system is deactivated. However, your ABS light may be caused by a malfunctioning wheel speed sensor. but that is not the reason for the rear end coming around.

Also another possible issue is - we have seen alot of issues with the wheel speed sensor jumper harnesses that run from the main body harness and then go to each front wheel speed sensor. they typically corrode and with continuous vertical movement from the control arms and also lateral movement from the wheels turning direction - left to right - it is a common point to see a broken wire at these points. sometimes you cant catch it with an DVOM either because there may be a couple strands of wire still attached, but the integrity of the circuit is still jeopardized because of the lack of electrical flow. These will typically throw a C0035 or C0040 in the EBCM set for left front or right front wheel speed sensor circuit malfunction.

 

Hi, I need some help from the auto world. I own a 2002 Chevy Malibu LS. When I start the car and drive for 3 to 4 miles the ABS system began to engage on its own. All four wheels will lock up. I have to pull over shut the car off for twenty minutes before the brakes free up on its own.
Here are the things I’ve done so far:
1. Replace rotors, pads, calibers and brake lines
2. Replace the ABS module
3. Master Cylinder
4. Vacuum hose to the booster
5. Inspected all brake lines and bleed them
6. Inspected shoes and drums with proper adjustment
7. Removed the fuse for the ABS (50a) to see if this problem would stop "No"!
8. Drained the fluid from value on the module also check the brake lines for air.
9. ABS light is not on If the fuse is in.
10. I’m all out of ideas do you have any suggestions?

 

Hello!! I am having the same issue with my 2002 Malibu. My ABS light will come on while driving then when I shut the car off and turn it back on the ABS light is off. Also when I drive a few blocks down the road my ABS will engage usually while turning and the light does not come on. Please help. I have had the brakes bled and the hub bearing replaced 3 times.