What causes the rear wheels to lock up?

Brake shoe contamination can be the cause of rear wheel lockup. If an axle seal or wheel cylinder leaks and contaminates the brake shoe(s) it changes the coefficient of friction. If it is mild contamination then the friction is increased while severe contamination will cause a reduction in friction (See Figure 61.9).

What happens if the rear wheel get locked?

“You do not want the rear wheel to lock first, ever, in a hard braking scenario. It will cause your vehicle to spin out of control. The car will most likely end up in an accident.

How can you regain control if your rear tire locks up?

To regain control of a locked rear wheel, the brake must be released. However, if you accidentally lock the rear brake on a good traction surface, you can keep it locked until you have completely stopped.

What would cause all 4 tires to lock up?

If the fluid is contaminated it will cause the rubber in the system to swell just as the other experts have mentioned. This would require replacement of all rubber components in the system if your fluid was contaminated. Another possible cause could be the hydraulic brake booster.

What happens when wheels lock up?

So when a wheel locks up the amount of braking force being applied goes down and the braking distance goes up. Anti-Lock Brakes keep lockup from happening. The next most important concept is that not all the wheels have the same amount of grip or the same amount of braking force for a bunch reasons.

What to do if tire locks up?

Pump the pedal to build up pressure. Slow your vehicle even more by applying the parking brake (if moving below 40 mph). Look for safe places where you can pull over that will slow the vehicle down, like gravel roads or flat, grassy fields.

What does it mean when your tires lock up?

Lock up essentially means that the braking force exceeds the frictional force that is keeping the tire in motion. It is usually caused braking while cornering due to the load transfer in the corner. The weight of the car is mostly onthe outside tires in the corner, so the frictional force on the inner tire is less.

Why does my tires lock up?

Tires can lock up during braking when a person attempts to stop suddenly on wet or slippery road or slams on the brakes instead of braking gradually. This causes an inability to steer or stop as quickly as possible, along with burning a flat spot on the tires from the friction of one patch of rubber hitting the road.

What can cause a rear wheel lockup problem?

Rear wheel lockup problems come in two broad categories. The first and most common are those caused by mechanical problems in the rear brakes. The second are those caused by hydraulic problems in the system.

Why does my drum brake lock up at the rear?

One of the most common causes of one or two wheel lockup on drum brake equipped vehicles is the service and/or parking brake adjustment. If either one or both of these adjustments are done incorrectly it can result in the rear brakes being very sensitive.

Can a out of round drum cause rear wheel lockup?

Brake drum condition should be factored in when determining the cause of rear wheel lockup. An out of round brake drum or drums that vary in diameter too much from side to side could cause a one wheel lockup condition (Figure 61.8). Measuring drum runout or out of roundness is not easy in the field.

What causes the rear passenger wheel to seize?

Either the caliper or parking brake can cause the wheel to seize. The dealer can loosen the bleeder screw, and if the wheel turns then the caliper is the problem. They can also check the parking brake. One member had a shop replace the rear rotors/brake pads (? IIRC) and the shop did not readjust the parking brake like they were supposed to.