2011-2015 Honda CR-Z Front vs Rear Brakes: What Wears First and What to Replace

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 2011-2015 Honda CR-Z the front brakes almost always wear out first. The fronts carry the thicker, ventilated rotors and twin-piston calipers because they do most of the stopping, while the rear solid discs do less work and usually last longer. Plan on front pads and rotors as the routine job, and inspect the rears every time the wheels come off rather than assuming they are fine.

How the CR-Z Brake System Is Laid Out

Honda built every CR-Z with four-wheel disc brakes, and the front and rear hardware is deliberately different. Here is what Honda's launch material lists for the car:

The system runs through a 4-channel ABS that modulates each wheel on its own, with Electronic Brake Distribution (EBD) that proportions brake power to the rear wheels based on vehicle weight distribution, plus brake assist for panic stops. A 9-inch power brake booster sits behind the master cylinder, and the stock wheels are 16-inch alloys on P195/55R16 tires. The fluid is Honda DOT 3; Honda's owner information warns that DOT 5 fluid is not compatible and can cause extensive damage.

The rotor diameters are nearly the same front and rear, so the difference is in the details: the front discs are thicker and ventilated, and the front calipers use two pistons instead of one. Honda explains that ventilated discs have fins cast between the two friction faces that pull air through the disc as it spins, which is how the front brakes shed the extra heat they generate.

Why the Front Brakes Wear First on a CR-Z

When you brake, the car's weight pitches forward onto the front tires. More weight on the front tires means they can use more braking force before they lock, so the system is designed to send most of the work there. EBD then trims rear braking to match how the car is loaded. The practical result: the front pads and rotors turn more of the car's speed into heat on every stop, so they wear faster.

The CR-Z adds one twist most cars do not have. Its Integrated Motor Assist (IMA) hybrid system uses the electric motor as a generator during braking. Honda describes the regenerative system as apportioning braking power in a linear fashion between the hydraulic brakes and the electric motor. Because the motor sits between the engine and transmission and drives the front wheels, some of the slowing that the front friction brakes would otherwise do is handled by the motor. That can stretch front pad life compared to a similar non-hybrid car, but it does not flip the pattern: the front friction brakes still do more of the hydraulic work than the rears.

A few habits change how fast either end wears:

• City driving and hard stops wear the fronts fastest, because hard stops push more weight forward and ask more from the friction brakes than gentle regenerative slowing can cover.
• Manual transmission cars with hill start assist briefly hold brake pressure at each wheel for about 1.5 seconds when you pull away on an incline. That is a small amount of pressure and not a wear concern on its own, but it is one more system that relies on healthy calipers at all four corners.
• Short trips and infrequent driving are hard on rear brakes. Lightly used rear calipers can corrode on their slide pins, which leads to rear pads that wear unevenly or drag even though they do little of the braking.

Symptoms: Which End Is Telling You Something

Most brake complaints on a CR-Z can be sorted to the front or rear with a little attention:

• High-pitched squeal - often a mechanical wear indicator touching the rotor. Wagner lists squeal as a sign of worn-out pads, glazing or irregularly worn discs.
• Grinding - Wagner ties grinding to pads worn out and in need of replacement. At that point the rotor is usually being damaged too, so expect to replace rotors along with pads.
• Pulsation in the pedal or steering wheel - pulsation you feel through the steering wheel usually points to the front rotors. Pulsation mostly in the pedal or seat with a steady wheel can point to the rears. Wagner connects pedal pulsation to irregularly worn discs.
• Pulling to one side - usually a front-axle problem: a sticking caliper, a contaminated pad or a pad worn completely on one side.
• Low fluid in the reservoir - Honda notes that a level at or below the MIN mark means the system should be inspected for leaks or worn pads. As pads wear, the caliper pistons move out and the fluid level drops. Do not just top it off; find out why.
• Brake warning light - on a CR-Z the brake system indicator can come on for low brake fluid. Power Stop explains that on vehicles with electronic wear sensors, a wire loop in the pad is exposed and breaks the circuit once the pad wears past its minimum.

The most reliable diagnosis is visual. Pull the wheels and look at the pad material on all four corners, including the inner pad, which is the one that often wears faster when a caliper slide is sticking. Measure rotor thickness with a micrometer and compare it to the minimum thickness cast into the rotor or listed in the factory service manual.

What to Replace: Front Job, Rear Job or Both

Front brakes

The front job is the one you will do most often. Replace pads in axle sets (both sides together), and replace the rotors when they are below minimum thickness, scored or causing pulsation. Because the front discs start out only 0.4 inch thick, there is not much material to machine, so new rotors are often the better value. Browse brake pads and replacement brake rotors for the CR-Z.

Rear brakes

The rear solid discs start out at 0.35 inch, so they have less material to begin with even though they wear more slowly. When you are in there, check that the pads move freely in their brackets and that the caliper slides are lubricated. If one rear pad is worn much more than the other, suspect a seized slide pin or piston before you blame the pads. The parking brake works on the rear brakes, so confirm it holds after a rear job, and follow the factory service manual for retracting the rear caliper piston; do not force it with a clamp if it will not move straight back.

Doing both ends at once

If the fronts are due and the rears are more than halfway worn, doing all four corners together saves a second teardown. That is what a matched set like our 2011-2015 Honda CR-Z front and rear brake kit is for: the correct front and rear parts in one box. Add a brake hardware kit for fresh clips and shims so the new pads do not rattle or squeal.

What to Replace at the Same Time

• Hardware and slide pin lubrication - worn clips and dry slides cause the tapered pads and uneven wear Wagner describes.
• Brake fluid - flush with Honda DOT 3 at the interval in your maintenance schedule. Honda allows DOT 4 from a sealed container as a temporary substitute, but calls for a flush and refill with Honda DOT 3 as soon as possible.
• Calipers - replace a caliper if the piston is seized, the boot is torn or it leaks, and replace in pairs on the same axle so braking stays even side to side. See brake calipers.
• Hoses - cracked or swollen flexible lines should be replaced during the job. See brake hoses.

How Hard Is the Job?

Front pads and rotors on a CR-Z are a reasonable driveway job for someone with a floor jack, jack stands, a torque wrench and basic sockets. Caliper bracket bolts are often tight and may need a breaker bar; torque every fastener back to the value in the factory service manual. Rotors on many Hondas are held by small retaining screws that can seize, so have an impact driver ready.

The rears take a little more care because of the parking brake. The hybrid battery and its control unit live beneath the rear cargo area, but wheel-end brake work does not involve them; leave any orange high-voltage wiring alone. After any brake job, pump the pedal several times before moving the car so the pistons seat against the new pads, then bed the pads in with a series of moderate stops. For everything else on this car, start at all brake parts.

Frequently Asked Questions

Do CR-Z rear brakes ever wear out before the fronts?

It is uncommon, but it happens when a rear caliper slide or piston sticks and keeps the pad dragging on the rotor. If your rears are worn more than your fronts, inspect the rear calipers before installing new pads.

Does regenerative braking mean my CR-Z brakes last forever?

No. The IMA motor handles part of the slowing during braking, which helps pad life, but the hydraulic brakes still do the rest, including most of a hard stop. Pads and rotors still wear and need regular inspection.

Should I replace rotors every time I replace pads?

Replace them when they are below minimum thickness, scored, heat-spotted or causing pulsation. Because CR-Z rotors are fairly thin from the factory, many owners replace them with the pads rather than machining.

What brake fluid does a Honda CR-Z use?

Honda specifies its DOT 3 brake fluid. DOT 4 from a sealed container is acceptable only as a temporary substitute, and DOT 5 must never be used.

Is a front and rear kit worth it instead of buying parts separately?

If both axles are due or close to it, yes. A matched front and rear kit gives you the correct pads and rotors for both axles and lets you do the whole car in one session.

Sources

1. Honda News: 2011 CR-Z Chassis - rotor sizes and thickness, caliper piston counts, 4-channel ABS with EBD, brake assist, 9-inch booster, wheel and tire sizes, hill start assist
2. Honda News: 2011 CR-Z Powertrain - IMA regenerative braking shares braking power between the hydraulic brakes and the electric motor; battery location
3. Honda Information Center: Ventilated Front Disc Brakes - how the internal fins of a ventilated disc pull air through and shed heat
4. Honda Owner's Manual: Brake Fluid - Honda DOT 3 fluid, DOT 4 as temporary substitute, DOT 5 incompatibility, low reservoir level can mean worn pads
5. Wagner Brake: Disc Brake Trouble - squeal, grinding, pulling, pulsation and tapered-pad wear causes
6. Power Stop: Brake Warning Light and Pad Replacement - how electronic pad wear sensors trigger a warning