1989-2002 Nissan Skyline Brake Noise: Squeal, Grinding and Pulsation Causes

By Core Brake Parts Tech Team — Circleville, OH warehouse

Most brake noise on a 1989-2002 Nissan Skyline comes down to four things: worn pads riding on their wear indicators (a constant squeal), glazed pads or rotors (a squeal or groan under braking), pads worn to the backing plate (grinding), and rotor thickness variation (a pulsing pedal or shaking wheel). The fix depends on which noise you have, and on a Skyline of this age the first job is confirming which brakes are actually on the car, because many have been swapped over the last 25-plus years.

Know Which Brakes Your Skyline Has Before You Diagnose

The 1989-2002 run covers three Skyline generations, the R32, R33 and R34, and the brake hardware changed a lot between trims. On the GT-R alone, the standard R32 GT-R used Sumitomo/Nissan front calipers on a 296 x 32 mm front rotor, while the R32 V-spec and V-spec II, and every factory R33 and R34 GT-R, used Brembo brakes: a four-piston front caliper on a 324 x 30 mm rotor and a two-piston rear caliper on a 300 x 22 mm rotor. Non-GT-R Skylines use different, smaller brakes again.

Because these cars are old and often imported secondhand, there is no guarantee the brakes on yours match the table. Measure the rotor diameter and thickness, count the caliper pistons and trace the pad shape before you order anything. A pad or rotor that is close but not correct is itself a common source of noise.

Squeal: Wear Indicators, Cold Squeak and Hardware

Nissan's own brake noise bulletin (NTB13-033e, which covers all Nissan vehicles) sorts squeals into a few types, and the same logic applies to a Skyline:

• Squeak on the first few stops of a cold morning. Nissan treats this as normal. If it goes away once the brakes warm up, no repair is needed.
• A loud, continuous squeal with or without braking. This is the pad wear indicator touching the rotor. The pads are worn out and need replacing now.
• Squeal at normal operating temperature. Usually a pad compound or installation issue. Check that the correct pads are fitted, that the shims, springs and clips are present and installed the right way, and that the hardware is lubricated where the service manual calls for it, never on the friction surface.
• Rear squeal. Nissan notes rear squeal is usually caused by brake dust and dirt packed between the pads and rotors. Cleaning the brakes with proper brake-dust precautions often cures it.

Performance pads make more noise than a stock street compound, and a Skyline fitted with track pads will squeal more at low speed no matter how well it is assembled. Noise comes from the whole assembly vibrating together - caliper, pad, rotor, knuckle and hardware - so a change to any one part can move or cure it.

Groan and Grinding: Glazing and Metal-to-Metal Contact

A groan during the stop is usually glazing. Nissan's bulletin links it to heavy or frequent braking that leaves a glassy layer on the rotor face; its repair is new pads plus resurfaced rotors finished with sandpaper. Skylines that see spirited driving or track days are prime candidates. A light groan as you ease off the pedal right after stopping, which Nissan calls creep groan, is normal.

Grinding is different and is not something to live with. A harsh metallic grind usually means the pad friction material is gone and the steel backing plate is cutting into the rotor, or that a stone or debris is trapped between the pad and rotor. Pull the wheel and look. If the backing plate has contacted the rotor, the rotor is almost always scored beyond saving and both pads and brake rotors need replacing as an axle set.

A single clunk from the front suspension when you first touch the brakes is usually the pads shifting in the caliper in the direction of rotation. Nissan's fix is to confirm the pads and their hardware are installed correctly and fit snugly.

Pulsation and Judder: Rotor Thickness Variation, Not Warping

If the pedal pulses or the steering wheel shakes under braking, the rotor is almost certainly the cause, but not because it warped from heat. Both Nissan and Wagner explain that pulsation comes from disc thickness variation (DTV): the two faces of the rotor are no longer flat and parallel, so the pads move in and out as the thick and thin spots pass through the caliper, and that motion is pushed back through the pistons into the pedal.

DTV usually starts with lateral runout. When a rotor does not sit true on the hub, the pads brush one spot on each side of the rotor every revolution even with the brakes off, and over time that wears the rotor unevenly. Wagner notes most vehicles have lateral runout limits of two thousandths of an inch or less, and that the leading cause is rust on the hub mating face preventing the rotor from seating flat. Power Stop's guidance is that thickness measured at six or more points around the rotor should not vary by more than .001 inch, and variation larger than .006 inch indicates DTV.

Two other judder causes Nissan calls out apply directly to Skylines that sit for long periods:

• Storage rust. A car that sits develops rust on the part of the rotor the pads do not cover. The friction differs between rusted and clean areas, and Nissan notes this can cause judder even after the rust wears off.
• Lug nut over-torque. Over-tightening lug nuts, especially with an impact wrench, contributes to judder. Tighten them by hand to the factory service manual value in a star pattern.

The Fix: Parts, Installation and Bedding

Match the repair to the noise:

1. Wear-indicator squeal or grinding: new brake pads, and new rotors if they are scored or below minimum thickness.
2. Glazing groan: new pads and resurfaced or replaced rotors, then a proper bed-in.
3. Pulsation: replace or resurface the rotors, clean the hub face, and check runout with a dial indicator before driving.
4. Hardware squeal or clunk: new shims, clips and slides from a brake hardware kit, lubricated only where the manual specifies.

When fitting new rotors, Nissan's bulletin describes indexing: clean the hub, mount the rotor with the lug nuts snugged, measure runout with a dial indicator, and if it is over the limit, rotate the rotor one stud position and measure again until you find the position with the least runout. If it is still over the limit, the rotor needs to be machined on the car.

Bed the new pads in. Nissan's burnish is ten medium stops from about 30 mph taking 3-5 seconds each, with about a minute of driving between stops to cool. Wilwood's procedure for its pads and rotors starts with light on-and-off stops, then medium stops, and finishes with 8-10 hard stops from 55-65 mph down to 25 mph, followed by a cool-down drive without holding the car on the brake pedal. Do bedding only where you can do it safely and legally.

Upgrading the Skyline Rear Brakes

If you are replacing worn rear brakes anyway and want more capacity, Wilwood makes a rear big brake kit for the Skyline. We carry the Wilwood Superlite 4R rear big brake kit with 13.50 in slotted rotors and red calipers. It uses a forged four-piston Superlite caliper, and Wilwood states its Skyline kits work with the factory master cylinder, ABS and electronic controls. Check that your wheels clear a 13.50 in rotor and confirm your chassis before ordering. You can browse more options in our brake parts section.

Difficulty: pad and rotor replacement on a Skyline is a reasonable driveway job for someone with jack stands, a torque wrench and a dial indicator. Caliper rebuilds, big brake kit installs and anything involving brake lines should end with a full bleed, and if you are unsure, have a shop do it.

Frequently Asked Questions

Why do my Skyline brakes squeak only in the morning?

Nissan's brake bulletin treats a squeak on the first few cold stops as normal. If it disappears once the brakes warm up, nothing needs fixing.

Are my Skyline rotors warped if the pedal pulses?

Almost never in the literal sense. Pulsation comes from disc thickness variation, which usually starts with runout from a rusty or dirty hub face. New or resurfaced rotors plus a clean hub and a runout check fix it.

Why do my Brembo-equipped R33 or R34 GT-R brakes squeal after new pads?

Check that the anti-squeal shims were reused or replaced, that the pads fit snugly in the caliper, and that they were bedded in. Aggressive performance compounds also squeal more at low speed than a street pad.

Can I keep my factory master cylinder with a Wilwood rear kit?

Wilwood states its Skyline big brake kits are compatible with the factory master cylinder, ABS and electronic controls, so no master cylinder change is required for the kit itself.

Should I replace pads and rotors together on a Skyline?

If the noise is grinding, glazing or pulsation, yes. Fitting new pads to a scored, glazed or uneven rotor tends to bring the noise back quickly.

Sources

1. Nissan NTB13-033e, All Nissan Brake Noise/Judder/Pedal Feel (NHTSA) - noise types, glazing, storage rust, lug nut over-torque, rotor indexing and burnishing
2. Skyline GTR USA, R32/R33/R34 Brembo brakes - factory GT-R caliper, rotor and master cylinder specifications
3. Wagner, Brake Pedal Pulsation and Disc Thickness Variation - DTV mechanism, runout limits and hub rust
4. Power Stop, Measuring Disc Rotor Run-Outs - rotor thickness measurement and DTV thresholds
5. Wilwood, Brake Pad and Rotor Bedding Steps - bedding procedure
6. The Brake Report, Wilwood Big Brake Kits for Skyline R32 - Skyline kit calipers, rotor sizes and OE master cylinder/ABS compatibility