What Causes the Feeling of Ineffective Braking When Reversing?
3 Answers
The feeling of ineffective braking when reversing may be caused by a malfunction in the car's braking system components, leading to a failure in the braking system. It could also be due to excessive wear on the car's brake pads or brake discs, resulting in a longer braking distance. Rust on car brake discs is a normal phenomenon. Light Rust: Light rust often occurs when the car is exposed to rain overnight or when it doesn't dry properly after washing. In such cases, continuous braking while driving can help remove the rust, as the friction between the brake disc and the brake caliper during braking will wear off the rust over multiple applications. Severe Rust: If the brake disc has severe rust, the entire surface may be covered with a thick layer of iron oxide. Stubborn rust can also accelerate the wear of brake pads, so it's necessary to take the car to a repair shop to have the brake discs polished.
I've been repairing cars for almost ten years, and soft brakes when reversing is a pretty common issue. The most likely culprit is a problem with the vacuum booster pump, which provides less assistance when reversing. If the brake fluid is deteriorated or has air in it, the pedal will also feel spongy. Also, check the brake discs and pads—especially if they're contaminated with oil, as that reduces friction. The scariest case I've seen was a customer with a slight brake fluid line leak; it was fine during normal driving, but when reversing, the system pressure changes exposed the issue. Another small detail: if the handbrake cable is stuck on an older car, it can create resistance when reversing. This isn’t something to take lightly—I’d advise against DIY fixes and recommend getting it on a lift for a pressure test right away.
Last week I almost hit a fire hydrant while reversing, and the car kept sliding even with the brakes fully pressed, which really gave me a scare. Later, the 4S shop inspection revealed that the brake discs had rusted and frosted over, and our residential underground garage is particularly prone to dampness. The mechanic taught me a little trick: after parking for a long time, first brake a few times while moving forward to warm up the brake discs before reversing. Now I’ve made it a habit, especially after rainy days, to lightly press the brakes twice before reversing. By the way, if you’ve just changed your tires, be extra careful. Once, I forgot to do brake maintenance after switching to wider tires, and the braking felt much weaker when reversing.
