2013-2015 Acura ILX Front vs Rear Brakes: What Wears First and What to Replace

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 2013-2015 Acura ILX the front brakes wear out first, usually well before the rears. Acura's own figures put roughly 61 percent of the car's resting weight on the front axle, weight shifts even further forward when you stop, and the front rotors are larger, vented and do most of the work. The rears still wear, though, and they deserve a measurement every time the fronts are done.

How the ILX brake system is laid out

Every 2013-2015 ILX uses power-assisted four-wheel disc brakes with ABS, Electronic Brake Distribution (EBD) and Brake Assist, plus Vehicle Stability Assist with traction control. Front and rear both use floating single-piston cast-iron calipers. What changes between versions is the front rotor size, which is why you must know your engine before ordering parts.

The rear rotor is the same across the range. The front is not: a 2.4L rotor will not fit a 2.0L caliper bracket, and aftermarket catalogs do not always agree with Acura's published Hybrid size. Measure the old rotor's outside diameter or check the size on the listing before you order.

Why the fronts wear first on an ILX

Three things stack up against the front axle:

• Static weight. Acura lists a 2013 ILX 2.0L Base at 2,910 lb with 1,786 lb on the front and 1,124 lb on the rear. That is about 61 percent front before you even touch the pedal.
• Weight transfer. Under braking the nose dives and more load moves onto the front tires. The Motorist Assurance Program notes that about 70 percent of braking force on a typical car is handled by the front brakes.
• Hardware sized for the job. The front rotors are vented and 1.1 in thick; the rears are solid and about a third of that thickness. The system is deliberately biased forward, because a car that locks its rear wheels first becomes unstable.

EBD adjusts that split based on load, so the rears do real work, especially with passengers or cargo aboard. The usual pattern is several front pad sets for every rear set, but that is a pattern, not a rule. Inspect both ends rather than assuming.

Symptoms and how to tell which end is worn

• High-pitched squeal while driving that changes with the pedal: usually a pad wear indicator tab touching the rotor. Pull the wheel on the end you suspect and look at the pad through the caliper window.
• Steering-wheel shake when braking from highway speed: points to the front rotors (uneven thickness or deposits). A shake felt in the seat or body more than the wheel can be the rears.
• Grinding or metal-on-metal noise: the pad friction material is gone. Stop driving on it; the rotor is being cut and will need replacing.
• Brake fluid near MIN: the owner's manual says a level at or below the MIN mark calls for an inspection for leaks or worn brake pads. Fluid drops slowly as pads wear because the caliper pistons sit farther out.
• Pulling to one side: a sticking front caliper slide pin or piston, or uneven pad wear side to side.
• Rear pads worn much faster than expected: check for a dragging rear caliper or a parking brake that is not fully releasing.

The fix: what to replace, front and rear

Pads are always replaced as an axle set (both sides), never one wheel. Rotors should be replaced in pairs on the same axle as well.

Front brake job

Match the rotor to your engine using the table above. For the Hybrid, our front drilled and slotted rotor pair for the 2013-2015 ILX 1.5L is listed for that version; confirm the diameter against your old rotor before installing. For the 2.0L and 2.4L, browse brake rotors and filter by your exact trim. Most daily-driven ILX owners do best with ceramic brake pads, which run quiet and keep the alloy wheels cleaner.

Rear brake job

The rear rotor is thin and solid, so it has little material to spare. If the rear rotors are scored, lipped or below the minimum thickness stamped on the rotor, replace them rather than resurfacing. The rear caliper also carries the parking-brake function on this car, so follow the factory service manual for retracting the rear piston; do not force it with a clamp if the manual calls for rotating it back.

Replace at the same time

• New abutment clips and shims from a brake hardware kit. Worn clips cause noise and uneven pad wear.
• Clean and re-lubricate the caliper slide pins with a brake-specific grease.
• Brake fluid if it is due. The manual specifies Honda Heavy Duty Brake Fluid DOT 3.
• A caliper if a piston is seized or a slide is frozen. See replacement brake calipers.

How hard is the job?

A front or rear pad and rotor job on the ILX is a reasonable driveway project for someone with a floor jack, jack stands, a torque wrench and basic hand tools. The main traps are ordering the wrong front rotor size, not cleaning rust off the hub face (which causes pedal pulsation later), and skipping torque specs. Torque the caliper bracket bolts and lug nuts to the values in the factory service manual, then bed in the new pads with a series of moderate stops before normal driving. If the fluid is dark or the pedal feels soft afterward, bleed the system.

Frequently Asked Questions

Does the 2013-2015 Acura ILX have rear disc or drum brakes?

Every version has rear discs. Acura specifies a solid 10.2-inch rear rotor on the 2.0L, 2.4L and Hybrid.

Are front rotors the same on the ILX 2.0L and 2.4L?

No. The 2.0L uses an 11.1-inch vented front rotor and the 2.4L uses a larger 11.8-inch vented front rotor. They are not interchangeable.

Should I replace front and rear brakes at the same time?

Only if both are worn. Fronts normally wear first. Measure the rear pads when you do the fronts; if they are close to the wear limit, doing both saves a second teardown.

What brake fluid does the ILX use?

The owner's manual calls for Honda Heavy Duty Brake Fluid DOT 3, and keeps the level between the MIN and MAX marks on the reservoir.

Why do my ILX brakes squeal right after new pads?

Common causes are reused clips or missing shims, glazing from not bedding the pads, or a dry slide pin. Replacing the hardware and bedding the pads fixes most cases.

Sources

1. Honda News - 2013 Acura ILX Specifications - front and rear rotor sizes by engine, caliper type, ABS/EBD/Brake Assist, curb weight and front/rear weight distribution
2. Acura News - 2014 Acura ILX Specifications - confirms the same brake hardware and rotor sizes for 2014
3. AcurInfo - Acura ILX Owner's Manual, Brake/Clutch Fluid - DOT 3 fluid specification and MIN/MAX reservoir guidance
4. Motorist Assurance Program - Which Brakes Go Bad First - front brakes handle about 70 percent of braking force
5. Auto123 - 2013 Acura ILX Technical Specs - four-wheel disc brakes with four-wheel ABS