2006-2009 Infiniti FX35 Brake Noise: Squeal, Grinding and Pulsation Causes

By Core Brake Parts Tech Team — Circleville, OH warehouse

Most brake noise on a 2006-2009 Infiniti FX35 comes from three things: a high-pitched squeal from pad vibration or a wear tab touching the rotor, a metal-on-metal grind from pads worn to the backing plate or a stone trapped behind the rotor, and a pedal or steering-wheel pulsation from uneven rotor thickness. Each one has a different fix, and only one of them is fixed by pads alone. Here is how to tell them apart and what to replace.

How the FX35 Brake System Is Laid Out

The FX35 uses disc brakes at all four corners: calipers clamp pads onto rotors that turn with the wheels. The parking brake is separate. Instead of clamping the rear pads, it uses a small pair of shoes that expand against a drum machined into the inside of each rear rotor hat. INFINITI lists genuine rear parking brake shoe sets for the FX35, and the part numbers change between the 2003-2008 trucks and the 2009-2012 trucks, so the 2009 model year does not share every brake part with 2006-2008. Always confirm fitment by year before ordering.

INFINITI's maintenance schedule calls for the pads and rotors to be inspected every 15,000 miles or 12 months in normal driving, and every 7,500 miles or 6 months in severe driving. The FX35 is a heavy crossover on large wheels, and a lot of them tow or live in stop-and-go traffic, which puts plenty of owners in the severe column.

Squeal: The Most Common Complaint

A squeal is vibration. Wagner's technical guidance puts it simply: vibration is the main source of noise in a brake system, and it usually comes from rust, loose or distorted parts, or a worn original part that no longer fits tightly. Ferodo classifies the familiar squeal as medium-frequency noise, roughly 300 to 5,000 Hz, and links it to sticky caliper pistons, rotors that are not flat, and badly installed shims.

Squeal that shows up only when you brake

• Missing or dry shims. Shims damp the vibration between the pad backing plate and the caliper. Pads that come with bonded shims only need a light coat of silicone brake lube on the back of the shim; pads without shims need the noise compound on the backing-plate contact areas.
• Dry or rusted slide points. If the pad ears are tight in the bracket, the pad cannot float and it chatters. Clean the abutments, replace worn anti-rattle clips, and lubricate metal-to-metal contact points with a high-temperature moly lube.
• Glazed pads or a rotor that was never bedded. New parts that were not burnished in can squeal until an even transfer layer forms.

Squeal that happens while driving, off the brake

A steady chirp or squeal that stops when you touch the pedal is the classic sign of a pad wear indicator. Many pads carry a small steel tab that starts rubbing the rotor when the lining gets thin, specifically so you hear it. Pull the wheel and look at the pads. If the lining is down near the tab, the noise is doing its job and the fix is new pads, not grease.

Grinding: Stop and Look Now

Grinding is the one noise not to put off. There are three usual causes on an FX35:

1. Pads worn through. Once the friction material is gone, the steel backing plate cuts the rotor. You will see deep grooves or a lip on the rotor face. At that point the rotors have to be replaced along with the pads, and the caliper piston should be inspected because it has been pushed far out of its bore.
2. A stone or rust flake between the rotor and the dust shield. This gives a scraping sound that comes and goes, often right after a gravel road. It can happen with good pads. Pull the wheel, remove the debris, and check that the shield is not bent into the rotor.
3. Rear parking brake shoes. Because the FX35 parking brake works inside the rear rotor hat, a broken shoe spring or shoes that drag can grind from the rear even when the pads are fine. If the noise is at the back and your pads look healthy, remove a rear rotor and inspect the shoes and hardware.

Ferodo describes low-frequency noise below 300 Hz, often called judder, as a sign of poor tolerances or disc damage, and recommends replacing the disc and cleaning all the assembly surfaces. A deep groan at low speed usually falls into that bucket.

Pulsation: Why the Pedal or Steering Wheel Shakes

Rotors on the FX35 rarely warp in the literal sense. What you feel is disc thickness variation. Wagner explains the chain: a rotor mounted with lateral runout wobbles, so each pad touches one spot of the rotor on every turn. Semi-metallic pads wear that spot thinner; ceramic pads leave deposits on it. Over a few thousand miles the rotor develops thick and thin areas, and each thick spot pushes the caliper pistons back as it passes. That is the pulse in the pedal. On the front axle you also feel it in the steering wheel.

The fix is new rotors (or resurfacing only if they stay above minimum thickness), a clean hub face, and lug nuts torqued to the value in the factory service manual in a star pattern. Skipping the hub cleaning is the main reason a new-rotor pulsation comes back within months.

The Fix, and What to Replace at the Same Time

For a squeal with healthy pads, a hardware service often cures it: clean and lube the slides, new clips, fresh shims. For worn pads, a pulsation, or any grinding, plan on pads and rotors together so the new pads bed onto a true surface. Our EBC Greenstuff 6000 front pad set DP61671 for the 2006-2009 FX35 3.5L is a direct front fit, and you can pair it with rotors from our brake rotor collection or browse all replacement brake pads.

While the wheels are off, also consider:

• A hardware kit. Clips and springs lose tension with heat; a brake hardware kit is cheap insurance against rattle and squeal.
• Caliper condition. A piston that is slow to retract or a seized slide pin causes uneven pad wear and heat. Replace a sticking unit from our brake caliper range.
• Rear parking brake shoes. On the rear axle, inspect the shoes and springs every time the rotors come off.
• Brake fluid. INFINITI notes that fluid absorbs moisture over time, which reduces braking efficiency and causes internal corrosion. Check the fluid type printed on the reservoir cap and change it as the schedule specifies.

How Hard Is the Job?

Front pads and rotors on the FX35 are a normal driveway job for someone with a floor jack, stands, a torque wrench and a caliper-piston tool. The rear axle takes a little more time because of the parking brake: the shoes sit inside the rotor hat, so back them off if the rotor will not slide off, and adjust them afterward so the parking brake holds properly. After any pad or rotor change, burnish the brakes. Wagner's procedure is 20 gradual stops from 50 mph down to 20 mph with light pressure and about 30 seconds between stops, and it prevents much of the squeal and uneven deposits people blame on the parts themselves.

NHTSA's recall database shows no service brake recalls for the 2006-2009 FX35 (the recalls on these years involve air bags, lighting, the fuel system and the steering column), so brake noise on these trucks is a wear and maintenance issue, not a known defect.

Frequently Asked Questions

Why do my FX35 brakes squeal after new pads?

Usually the pads were not burnished, the shims or backing plates were not lubricated, or the old clips and dry slide pins were reused. Clean and lube the contact points, fit new hardware, and run the bedding procedure before blaming the pads.

Is grinding from the rear always the pads?

No. On the FX35 the parking brake shoes live inside the rear rotor hat, so a broken spring or a dragging shoe can grind with good pads. Debris behind the dust shield is another common cause.

Can I just resurface my rotors to stop the pulsation?

Only if they stay above the minimum thickness stamped on the rotor after machining. If the hub face is rusty, clean it first or the pulsation returns. Many owners replace rotors because resurfaced rotors have less mass left to absorb heat.

Do 2009 FX35 brake parts match 2006-2008?

Not all of them. INFINITI lists different parking brake shoe part numbers for 2009-2012 than for 2003-2008. Some aftermarket pads cover 2006-2009, but always verify each part by year.

How often should FX35 brakes be inspected?

INFINITI's schedule says every 15,000 miles or 12 months in normal driving and every 7,500 miles or 6 months in severe service such as towing or heavy city driving.

Sources

1. INFINITI USA maintenance schedule, 2008 FX35 brake pads and rotors - pad and rotor inspection every 15,000 miles or 12 months, 7,500 miles or 6 months for severe driving
2. INFINITI USA maintenance schedule, 2008 FX35 brake fluid - brake fluid absorbs moisture and must be inspected and replaced as specified
3. Genuine INFINITI FX35 parking brake shoe catalog - rear parking brake shoe sets for the FX35, with different part numbers for 2003-2008 and 2009-2012
4. Wagner Brake - Brake System Noise Troubleshooting Tips - vibration as the source of squeal, hub rust, clips, guide pins, shim lubrication and the 20-stop burnish procedure
5. Wagner Brake - Brake Pedal Pulsation and Disc Thickness Variation - how lateral runout creates thickness variation and pulsation; hub rust as the main cause; runout of two thousandths of an inch or less on most vehicles
6. Power Stop - Pulsing or Vibrating Brake Pedal and DTV - thickness variation over .006 inch indicates rotor replacement; measure at six points with a micrometer
7. Ferodo - Brake Noise Technical Tips - low, medium and high frequency noise bands and their typical causes
8. NHTSA recall database, 2008 INFINITI FX35 - FX35 recalls for 2006-2009 cover air bags, lighting, fuel system and steering column, none for the service brakes