Braking should be smooth and predictable at all times. Anything beyond this is unacceptable and hints at a problem in the braking system. Something is definitely wrong if you feel some slight to major vibrations when you apply pressure on the brake pedal.
ProTip: Brakes should bite smoothly and gradually. A pedal drop before braking, a spongy feel, or unpredictable braking force is also not normal.
A couple of things can make your car vibrate even when not braking. You will have to pay close attention and ensure that the shaking only happens when you brake otherwise, you will misdiagnose the problem.
If you are right, you will be dealing with brake shudder.
Stop. Check the Obvious
Even though shaking while braking logically hints at a problem with the braking system, it could hint at other different and frankly easy to fix problems. Here are some things to check on first:
- Damaged tires with worn tread or even bulges
- Unbalanced wheels
- Front end out of alignment
- A loose control arm or damaged steering knuckle
- A loose lug nut
How Does Brake Shudder (Judder) Feel Like?
While brake shudder also shakes the rest of the car, it is mostly felt on the steering wheel and the brake pedal when you apply brakes at speed. The vibration ranges from mild shudders to violent shaking.
In most cases, you can narrow down the culprit to the front axle or the rear axle, depending on where you feel the shudders the most. If the steering wheel shakes more, then it is your front axle. Rear axles send vibration feedback through the brake pedal as they’re not connected to the steering wheel.
What Makes Your Car Vibrate When Braking?
In most cases, the vibrations during braking are due to imperfections in your braking system. The most common issues that will manifest as brake judder include:
Warped Brake Rotors
Warped brake rotors (brake discs) are the most common cause of shaking as you brake.
The vibration could be due to uneven wear on the rotor’s surface, creating little hills and valleys. More often than not, it happens when your rotors warp due to repeated heating and cooling when under heavy use.
Warping is common in old rotors that have worn thin below the recommended operating thickness.
It is common in very old brake rotors or low-quality aftermarket rotors.
The uneven surface will ‘wobble’ as it spins. The wobble translates to vibrations as your brake pads skim over these imperfections when trying to stop or slow down the vehicle at high speeds.
How to Fixed Uneven Rotors
If the unevenness is due to brake pad damage or rust, it should go away as soon as you replace the pads and wait until they rub and smooth the rotor surface again.
In most cases, you will have to re-machine (skim) the rotor surfaces to get rid of the blemishes faster. Note that you can’t skim some OEM or aftermarket brake rotors. Even those that can be skimmed have a minimum width figure, and you should never skim or use them below this width.
If the rotors are warped or very thin, the ultimate solution would be getting replacement rotors.
Bad Brake Pads
Old or poor-quality brake pads might have trouble grabbing onto an otherwise perfect brake rotor.
Besides the vibration, you will also hear a squeaking sound or slight grinding when braking at low speed.
Brake pads will also cause vibration if contaminated with dirt or oil as they don’t have an even braking surface.
Poor quality brake pads might be cheap, but there’s no guaranteeing how well they will age. If they don’t wear unevenly, they will abrade your rotors or won’t provide enough consistent braking power.
Check this too: How Often Should You Change Brake Pads?
Stick with known-brand high-quality aftermarket brake pads or shop for OEM replacements. Only go for aftermarket if you are sure they are of better quality than what your OEM replacement offers.
Sticky Brake Calipers
Though uncommon, stuck brake calipers can also lead to brake vibrations. In this case, the callipers will be stuck such that they can’t evenly react to the hydraulic pressure from the master cylinder.
Consequently, they won’t press the brake pads against the rotors evenly, leading to uneven braking that can be picked up as vibrations if fast enough.
Problems With Your Suspension or Alignment
You can also get a shudder when you brake if your vehicle is out of alignment. Misaligned tires will put more strain on a suspension.
The extra stress either wears down crucial suspension components like tie rods, ball joints, and wheel bearings. This will either amplify any imperfections in the suspension components as you brake or completely wear them out, forcing them to shake and vibrate even under normal driving.
How to Fix Brake Shudder
If your vehicle’s shaking is due to damaged braking components or alignment issues, you should fix the damaged components to sort the problems. You can pinpoint the problem after a quick inspection (or after a mechanic looks at your car)
- If it’s the rotors, have them resurfaced or replaced. If you replace rotors, be sure to replace the brake pads too
- Replace the brake pads
- Have your wheels aligned
- Inspect the suspension and replace any damaged components like ball joints, bushings, and tie rods
How to Prevent Your Brakes From Shuddering
In most cases, your brakes will start shaking after years and years of use. How soon it starts depends on how you drive. Here are some pointers to avoid it – or prevent it from kicking in sooner.
- Inspect your brakes frequently and have the brake pads or rotors changed as soon as they show signs of wear
- Only install high-quality brake pads or stick to OEM pads. Don’t cheap out
- Avoid speeding and braking hard like speeding from traffic light to light. This overheats the rotors making them susceptible to warping. It also wears your pads faster
- Don’t ride brakes for long when going downhill. The extreme heat might be more than your rotors can take
- Know when to replace your brake rotors (when their width dips below manufacturer recommendation
- If you tow often, get a braked trailer or camper to take most of the pressure off your vehicle’s braking system
- Check your vehicle’s alignment and suspension frequently and capture deviations or damage in time
Bottom Line
If you are careful and inspect (or take your car for inspection) often, chances are you will never get the annoying brake shudder. You might not even encounter it if you drive new cars and sell out as soon as the mileage nears 30K.
After all, most brake pads, rotors, and suspension components will easily coast through 30K miles without needing replacement.
In an older car, have them inspected and serviced before they wear to prevent them from taking down other things in the process.
Also, drive carefully and avoid unnecessary braking as it will put extra strain on your brakes wearing and damaging them sooner than they should.