2008-2015 Infiniti G37 Brake Caliper Problems and Replacement

By Core Brake Parts Tech Team — Circleville, OH warehouse

Most brake caliper trouble on a 2008-2015 Infiniti G37 comes down to one of three things: a piston or slide that sticks and drags, a seal that weeps fluid, or old, wet brake fluid that has corroded the caliper from the inside. The fix is usually a replacement or resealed caliper plus fresh pads and a full fluid flush - but first you need to know which of the two factory brake systems your G37 has, because the calipers, rotors and pads do not interchange.

Two Brake Systems: Standard vs Sport (Akebono)

The G37 was built with two brake packages. Cars without the Sport package use a smaller standard brake with smaller rotors. Cars with the Sport package got Akebono fixed calipers: 4-piston calipers in front and 2-piston calipers in the rear, clamping 14-inch front rotors and 13.8-inch rear rotors. Infiniti moved its sport package to Akebono brakes starting in 2008, and the same Akebono calipers are used on the Nissan 370Z, interchanging between the two cars with the same hardware.

This matters for every part you buy. A Sport caliper will not bolt onto a standard-brake car without the matching larger rotors, pads and lines, and the conversion needs modified dust shields and wheels with enough clearance for the bigger calipers. Pad listings follow the same split: for example, our Hawk HPS front pad set for the G37 Sport is for Akebono-equipped cars. Check your trim, and look through the wheel spokes, before ordering.

Symptoms of a Failing G37 Caliper

• Pulling to one side under braking. A caliper that grips harder or softer than its partner on the same axle pulls the car toward the stronger side.
• A burning smell or one very hot wheel after a drive. A dragging caliper keeps the pads in contact with the rotor. That wheel runs noticeably hotter and dustier than the others.
• Uneven pad wear. One pad worn far thinner than the other in the same caliper, or one side of the car wearing much faster, points to a stuck piston or (on standard brakes) a seized slide pin.
• Fluid on the inside of the wheel or tire. A leaking piston seal or bleeder leaves a wet, oily film. Brake fluid strips paint and a leak should never be ignored.
• Soft or sinking pedal, or a dropping fluid level. A leak lets fluid out and air in. If the reservoir keeps going down and worn pads do not explain it, find the leak before driving further.
• Clunk or rattle over bumps. Missing or worn pad pins, clips or abutment hardware let the pads move inside the caliper.

Diagnosing the Problem

Start simple. After a normal drive with no hard stops, carefully compare each wheel by holding your hand near the center of the wheel - do not touch the rotor. One wheel far hotter than its partner on the same axle is the classic sign of a dragging caliper.

Next, get the car safely on jack stands and spin each wheel by hand with the transmission in neutral. A light brush of pad contact is normal; a wheel that is hard to turn, or that stops the instant you let go, is not. Then pull the wheels and look at the pads. Compare the inner and outer pads on each caliper. On the Akebono Sport calipers, uneven wear across the pad usually means one or more pistons are sticking. Inspect the dust boots around each piston for tears, and look for wetness around the pistons, the bleeder and the hose fitting.

Finally, check the brake fluid. Dark, cloudy fluid has absorbed moisture, which is the root cause of a lot of internal caliper corrosion. If the fluid has not been changed on schedule, treat all the calipers as suspect even if only one is acting up.

Common Causes

Old brake fluid

Brake fluid absorbs moisture over time. INFINITI's maintenance guide for the 2012 G37 explains that water in the system can turn into a compressible gas and reduce braking efficiency, and it calls for replacing the fluid every 30,000 miles or 24 months under standard driving, or every 15,000 miles or 12 months under severe driving. That same moisture corrodes pistons and bores, which is what makes them stick.

Torn dust boots

Once a piston boot tears, road water and grit reach the piston surface. Rust builds on the exposed piston, it starts to drag, and eventually it seizes.

Worn seals

Piston seals harden with age and heat. A tired seal can weep fluid or fail to pull the piston back when you release the pedal, leaving the pads lightly clamped on the rotor.

Hardware wear

Pad pins, pin clips and abutment clips wear and corrode. Rusted hardware lets pads hang up in the caliper even when the pistons are fine.

The Fix: Reseal, Remanufactured, or New

You have three realistic options for a bad G37 caliper:

1. Reseal the caliper you have. Rebuild seal kits for the Akebono Sport calipers include the seals and rings to redo a pair of calipers. This is a good route when the pistons and bores are clean and only the seals are tired. It is not a good route if the pistons are pitted - a new seal on a rough piston will leak again.
2. Install a remanufactured caliper. Quality remanufactured units come with new pistons, seals, dust boots and bleeder screws and are pressure tested before shipping. Some remanufactured Sport calipers ship without mounting brackets, so you reuse your existing brackets.
3. Install a new caliper. OEM Akebono Sport calipers are sold for the G37 and 370Z, often as the caliper only with hardware sold separately.

Whichever you choose, replace calipers in pairs across an axle when the car has any age on it. A fresh caliper on one side and a tired original on the other can pull under braking. Browse replacement brake calipers by fitment, and confirm Sport vs standard before you order.

What to Replace at the Same Time

• Pads. A dragging caliper overheats and glazes its pads, and a leaking caliper can soak them in fluid - contaminated pads cannot be cleaned and must be replaced. For the front we carry the EBC Bluestuff NDX front pad set for the G37 3.7, and for the rear the EBC Bluestuff NDX rear brake pads. Confirm the listed fitment matches your brake package. More options are in our brake pads collection.
• Rotors. Heat from a dragging caliper often leaves the rotor with hard spots, bluing or thickness variation. Measure them against the minimum thickness stamped on the rotor, or replace them with new brake rotors sized for your brake package.
• Hardware. New pins, clips and abutment hardware cost little and keep the new parts from hanging up. See our brake hardware kits.
• Brake hoses. A hose that has collapsed internally can hold pressure on the caliper and mimic a stuck piston. If a new caliper still drags, check the hose. See our brake hoses.
• Brake fluid. Any caliper job opens the hydraulic system, so finish with a complete flush and bleed using the fluid type listed in your owner's manual and on the reservoir cap.

How Hard Is the Job?

Replacing a G37 caliper is a moderate job for someone with jack stands, a torque wrench and a helper for bleeding. Sport calipers are fixed calipers, and the pads are held in by pad pins and clips rather than sliding brackets. Standard brakes follow the familiar sliding-caliper layout. The hard parts are keeping the system clean and getting every bit of air out: bleed the whole system, not just the wheel you worked on, and a firm pedal is the only acceptable result.

Torque the caliper and bracket bolts to the values in the factory service manual - never guess on the bolts that hold the brakes to the car. Bed in new pads with a series of moderate stops before normal driving. Before any of this, run your VIN through INFINITI's recall lookup to confirm there is no open campaign that would cover the work.

Frequently Asked Questions

How do I know if my G37 has the Sport brakes?

Look through the wheel. Sport-package cars have large Akebono calipers with the name on them - 4-piston in front and 2-piston in the rear - and bigger rotors (14 inches front, 13.8 inches rear). Standard brakes are smaller and unbranded. Your window sticker or build sheet will also list the Sport package.

Can I put Akebono Sport calipers on a base G37?

Yes, it is a common upgrade, but it is more than calipers. You need the Sport rotors, matching pads and brake lines, the dust shields have to be modified, and your wheels must clear the larger calipers.

Are G37 and 370Z Akebono calipers the same?

Yes. The Sport Akebono calipers interchange between the Infiniti G37 and Nissan 370Z, and the hardware is the same.

Should I rebuild or replace a sticking caliper?

Rebuild if the pistons and bores are smooth and only the seals or boots are bad. Replace if the pistons are pitted or rusted, the bleeder is seized, or the caliper has been leaking for a while. Resealing a rough piston rarely lasts.

Do I need to replace both calipers?

Replacing them in pairs on the same axle is strongly recommended so braking force stays even side to side. On an older car, the other caliper has lived with the same fluid and weather and is usually not far behind.

How often should G37 brake fluid be changed?

INFINITI's 2012 G37 maintenance guide lists every 30,000 miles or 24 months for standard driving and every 15,000 miles or 12 months for severe driving. Fresh fluid is the cheapest caliper protection there is.

Sources

1. Akebono Sport brake kit fitment (G37/Q60) - 4-piston front and 2-piston rear Sport calipers, 14 in front and 13.8 in rear rotors, Sport-package factory fitment, dust shield and wheel clearance notes
2. OEM Infiniti G37 Sport caliper (Akebono) - 4-piston OEM Sport caliper, 370Z/G37 interchange, caliper sold without hardware
3. Akebono front caliper rebuild seal kit - seal and ring kits for resealing leaking Sport calipers
4. Power Stop Akebono Sport rear calipers - remanufactured Sport calipers ship without brackets, are pressure tested, and require Sport rotors, pads and lines
5. INFINITI 2012 G37 brake fluid maintenance guide - fluid replacement every 30,000 miles or 24 months (15,000 miles or 12 months severe) and why moisture hurts braking
6. INFINITI recall VIN lookup - owners check open recalls by VIN