1991-1993 Mitsubishi 3000GT Front vs Rear Brakes: What Wears First and What to Replace

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 1991-1993 Mitsubishi 3000GT the front brakes almost always wear out first. The front rotors are larger and the front pads do most of the stopping, so plan on replacing front pads and rotors before the rears, and inspect the rears every time the fronts come off. Which parts fit depends heavily on whether you have a base, SL or VR-4, so confirm your trim before you order anything.

How the Brakes Are Laid Out on the 1991-1993 3000GT

Every first-generation 3000GT, from the base car to the twin-turbo VR-4, came with four-wheel disc brakes as standard equipment. Anti-lock brakes were standard on the SL and VR-4 and optional on the base coupe. That means there are no rear drums or shoes to deal with on any trim: you are servicing pads and rotors at all four corners.

The trims are not interchangeable at the brakes. The base and SL are front-wheel drive, while the VR-4 has permanent all-wheel drive, four-wheel steering, a twin-turbo V6 and a noticeably larger brake package. The VR-4 is also split by production date: some aftermarket kits list fitment for VR-4 cars built only through May 1993, so check the build date on the door jamb label before buying VR-4 parts for a late 1993 car.

Here is how the rotors compare, using the published specs for replacement rotors built to the factory dimensions:

The VR-4 front rotor is both larger in diameter and thicker than the base and SL front rotor, and both VR-4 rotors are vented. A rotor that fits one trim will not fit the other, which is the single most common ordering mistake on these cars.

Why the Front Brakes Wear First

When you brake, the weight of the car pitches forward onto the front tires. The front tires gain grip and the rears lose some, so the brake system is designed to send more of the clamping work to the front. The 3000GT is a heavy car for its size, with the coupe weighing roughly 3,100 to 3,400 pounds depending on trim and year, and in the front-drive base and SL cars the engine and transaxle sit over the front axle. All of that energy turns into heat in the front pads and rotors.

The practical result: on a typical daily-driven 3000GT you will replace front pads more often than rear pads, and front rotors tend to reach minimum thickness or develop runout (the pulsing you feel in the pedal) sooner. The rears are not maintenance-free, though. Rear pads can wear unevenly if a caliper slide pin or piston is sticking, and a car that sat for years often comes back with rusted rear rotor faces even when the pads look thick.

Symptoms and How to Tell Front From Rear

• Pulsing in the brake pedal or steering wheel: steering wheel shake under braking usually points to the front rotors. Pulsing felt only in the pedal or the seat can be the rears.
• Squeal or grinding: a high-pitched squeal is often the wear indicator touching the rotor. Grinding means metal on metal, and the rotor is usually ruined at that point.
• Pulling to one side: usually a front caliper that is sticking or a pad contaminated with fluid or grease.
• Brake warning light or a low fluid level: worn pads lower the reservoir level a little, but a sudden drop means a leak. Check the front hoses first on these cars (see the recall below).
• One rear wheel much hotter than the other after a drive: a dragging rear caliper or a parking brake adjustment problem.

The only way to know for sure is to pull the wheels. Measure rotor thickness with a micrometer at several points and compare it to the minimum thickness cast into the rotor. Check pad lining thickness at both ends of each pad, inner and outer. A big difference between inner and outer pads points to a caliper that is not sliding or releasing freely.

The Front Brake Hose Recall You Should Know About

NHTSA recall campaign 96V143 covers 3000GT cars built between August 1, 1990 and November 4, 1993. Under full-lock steering combined with full suspension travel, the front wheel-side brake hoses could crack and leak fluid. The recall notice states that the leak lights the brake warning lamp and reduces braking effectiveness. The remedy was for dealers to replace both front wheel-side hoses with revised hose assemblies.

On a car this old, you cannot assume the revised hoses are still on it, or that they are in good shape even if they are. Any time you do front brakes on a 1991-1993 3000GT, inspect the front hoses at full lock in both directions. Look for cracks, bulges, weeping at the crimps and rubbing marks. If they are cracked or of unknown age, replace both front hoses. Rubber hoses harden with age regardless of mileage. Replacement brake hoses and brake lines are a small cost next to a sudden loss of pressure.

What to Replace, and What to Replace Together

Front brake job

• Pads and rotors as a set. On a car this age, most front rotors are near or below minimum thickness by the time the pads are done. New rotors with new brake pads give the pads a flat, clean surface to bed into and cure most pedal pulsation.
• Hardware. Anti-rattle clips and shims lose tension and corrode. A brake hardware kit is cheap insurance against noise and uneven wear.
• Front hoses if they show any of the damage described above.
• Calipers only if a piston is seized, a boot is torn or the caliper is leaking. A sticking caliper will wear out new pads quickly. Rebuilt brake calipers are the fix when a rebuild at home is not practical.

Rear brake job

• Inspect every time the fronts are done. Replace the rear pads when they approach the wear limit rather than waiting for noise.
• Rotors if they are worn, scored or rust-pitted. Check a VR-4 rear rotor against the 18.4 mm minimum published for replacement rotors, or against the value cast into the rotor on any trim.
• Check the parking brake for correct adjustment and free cable movement after the rear job.

Brake fluid

Old fluid absorbs moisture, which lowers its boiling point and corrodes the ABS unit and calipers from the inside. Flush the system with the fluid type printed on the master cylinder reservoir cap whenever you replace calipers or hoses, and bleed in the order given in the factory service manual, especially on ABS-equipped SL and VR-4 cars.

Doing Both Axles at Once

If both ends are due, or you are bringing a stored 3000GT back to the road, doing all four corners at once saves labor and gives you matched friction front and rear. Our 1991-1993 Mitsubishi 3000GT front and rear brake kit covers both axles in one order; confirm its trim fitment matches your car before you buy. You can also browse individual brake rotors and ceramic brake pads if only one axle needs work.

Difficulty: a front or rear pad and rotor job on a 3000GT is a moderate driveway job with basic hand tools, a torque wrench, a caliper piston tool and jack stands. Torque the caliper bolts and lug nuts to the values in the factory service manual. Hose replacement and a full fluid flush are also doable at home, but ABS-equipped cars take more care during bleeding. Always bed in new pads before normal driving.

Frequently Asked Questions

Do the front brakes on a 3000GT really wear faster than the rears?

Yes. Weight shifts forward under braking and the front rotors are larger, so the front pads do most of the work and usually wear out first. Still inspect the rears at every front brake job.

Will VR-4 brake parts fit my base or SL 3000GT?

No. The VR-4 front rotor is larger and thicker than the 276 mm base and SL front rotor, so the parts are trim specific. Always order by exact trim.

Does my 1991-1993 3000GT have rear drum brakes?

No. Four-wheel disc brakes were standard on every 3000GT trim, so every corner uses pads and rotors.

How do I know if my car was part of the front brake hose recall?

Recall 96V143 covers 3000GT cars built from August 1, 1990 through November 4, 1993. Check the build date on the door jamb label and look up your VIN on the NHTSA recall site. Either way, inspect the front hoses on a car this old.

Should I replace rotors every time I replace pads?

Replace them whenever they are below the minimum thickness cast on the rotor, warped, heavily scored or rust-pitted. On most 1991-1993 cars that is the case, so pads and rotors together is the usual job.

Sources

1. Consumer Guide: 1991-99 Mitsubishi 3000GT - four-wheel discs standard, ABS by trim, VR-4 AWD and four-wheel steering, curb weight range, front brake hose recall
2. NHTSA campaign 96V143 (Justia recall database) - hose defect, production dates, consequence and remedy
3. DBA 4000 T3 front rotor for 3000GT - base and SL front rotor 276 mm, 24 mm thick, 22.4 mm minimum
4. Centric rear rotor for 1991-1993 3000GT VR-4 - vented 284 mm rear rotor, 20 mm thick, 18.4 mm minimum
5. Power Stop Z23 kit for 1991-5/1993 3000GT VR-4 - VR-4 front rotor 11.7 in by 1.2 in, vented rear 11.2 in, production-date split