1999-2009 Honda S2000 Brake Caliper Problems and Replacement

By Core Brake Parts Tech Team — Circleville, OH warehouse

Most Honda S2000 caliper trouble comes down to three things: slide pins that have lost their grease, a rear caliper piston that was pushed back instead of screwed back during a pad job, and old brake fluid corroding the piston bore. A dragging or seized caliper shows up as a pull to one side, a hot or smelly wheel, and one pad worn far thinner than its partner. Fix the cause, not just the pads, and the S2000's brakes are simple to keep healthy.

How the S2000 Caliper Setup Works

From the factory the S2000 runs disc brakes at all four corners with single-piston floating calipers. A floating caliper has one piston on the inboard side; when you press the pedal the piston pushes the inner pad into the rotor, and the caliper body slides on two guide pins to pull the outer pad in from the other side. That sliding motion is the whole design, which is why the guide pins matter so much. If a pin seizes, the caliper cannot center itself and one pad does most of the work while the other drags or barely touches.

The rear calipers add a second job: the parking brake is built into them. Instead of a separate drum-in-hat parking brake, the rear piston is driven by a mechanical screw mechanism when you pull the handle. That is convenient, but it changes how you service the rear pads, which we cover below.

All of this runs on the fluid Honda specifies: Honda Heavy Duty Brake Fluid DOT 3. The owner's manual allows DOT 3 or DOT 4 from a sealed container only as a temporary measure and warns never to use DOT 5.

Symptoms of a Bad or Sticking Caliper

• Pull to one side under braking. One front caliper clamping harder than the other steers the car toward the stronger side.
• A hot wheel or burning smell after a drive. A caliper that will not release keeps the pad rubbing, and that wheel will run noticeably hotter than the others.
• Uneven pad wear. An inner pad worn to the backing plate while the outer pad looks fine points at a stuck guide pin. ADVICS lists brake noise and excessive pad wear as the classic signs of slide pin sticking.
• Blue or heat-checked rotor on one corner. Constant drag overheats the rotor on the affected wheel.
• Fluid on the inside of the wheel or a dropping reservoir. A leaking piston seal lets fluid out. Honda's manual says a level at or below MIN means the system should be checked for leaks or worn pads.
• Weak parking brake or a rear that drags after releasing it. On the S2000 this often traces to the rear caliper's built-in parking brake mechanism rather than a cable.

What Causes S2000 Caliper Problems

Dry or rusted guide pins

ADVICS, a major OE brake supplier, lists the root causes of slide pin sticking as the pin itself seizing, rust forming once the grease is used up, and heat breaking down the pin boot and sleeve. Once the boot tears, water gets in and the pin corrodes in its bore. On a car that often sits for a season, as many S2000s do, this is the most common caliper fault.

Old, wet brake fluid

Brake fluid absorbs moisture over time. That water corrodes the piston and bore from the inside and eventually makes the piston hang up. Honda tells owners to replace the fluid on the time interval in the maintenance schedule, and warns that non-Honda fluids can cause corrosion and shorten system life.

Rear piston forced back instead of screwed back

Because the rear piston carries the parking brake screw, you cannot simply push it back with a C-clamp like a front piston. It has to be rotated clockwise until it sits flush, with its cross-shaped groove lined up so the nub on the back of the inner pad drops into it. Forcing it straight back can damage the internal mechanism, and a misaligned pad can leave the parking brake weak or the rear dragging.

Torn piston boot

A split dust boot lets grit and water reach the piston. The piston scores, the seal leaks, and the caliper starts sticking. Once a piston is pitted, the caliper should be replaced rather than just resealed.

How to Diagnose Which Caliper Is at Fault

1. After a normal drive, carefully compare the heat of each wheel near the hub without touching the rotor. One wheel much hotter than the others is your suspect.
2. With the car safely supported and the parking brake released, spin each wheel by hand. Light pad contact is normal; a wheel that is hard to turn is dragging.
3. Pull the pads and compare inner and outer thickness. A big difference on one caliper points at the guide pins.
4. Remove the guide pins and check them. Rust, pitting, or a pin that will not slide freely means clean and relube or replace; a torn boot always gets replaced.
5. Inspect the piston boot and look for wet fluid around the piston. Any leak means a new or remanufactured caliper.
6. For the rear, confirm the parking brake lever returns fully and the wheel spins freely once the handle is released.

The Fix: Service, Replace, or Upgrade

Replacement calipers and guide-pin hardware are in our brake calipers and brake hardware kits collections. When a caliper is replaced, bleed the system with fresh fluid of the correct spec. If the car has had many years on the same fluid, flush all four corners.

Owners who track the car often go past stock parts. Brembo describes its GT | S kits as built for drivers who regularly hit the track, with race-style ventilated pistons, recessed dust seals and hard anodized calipers, and every GT kit pairs the calipers with larger discs, performance pads and braided stainless hoses. For 1999-2005 cars we carry the Brembo GT-S six-piston front big brake kit for the S2000. Before ordering any big brake kit, confirm your wheels clear the larger caliper.

What to Replace at the Same Time

• Pads on both sides of the axle. Never replace a single corner's pads.
• Rotors that are overheated, scored or below minimum thickness. A dragging caliper usually cooks its rotor. DBA's 4000 Series uses its Kangaroo Paw vane design and a heat treatment it calls Thermal Stability Profiling. For 2000-2005 cars we stock the DBA 4000 T3 slotted front rotor, the DBA 4000 T3 slotted rear rotor, and the DBA Street Series T2 front rotor. For all 1999-2009 cars there is the GiroDisc slotted front rotor set.
• Brake hoses on an older car. Rubber hoses age too, and a collapsed hose can mimic a sticking caliper by trapping pressure. The Russell stainless braided line kit for 2000-2006 S2000s replaces them and firms up the pedal.
• Brake fluid. Any time the system is opened, bleed it with fresh fluid.

How Hard Is the Job?

Front caliper replacement on the S2000 is a straightforward driveway job for someone with basic tools, a torque wrench and a way to bleed the brakes. The rear is a notch harder: release the parking brake before removing the caliper, rotate the piston clockwise to retract it rather than pressing it, align the piston groove with the pad nub, and check parking brake operation before driving. Torque all caliper and bracket bolts to the values in the factory service manual. If you have any doubt about the parking brake mechanism or bleeding, have a shop do it.

One more check on 2006-2007 cars: NHTSA campaign 13V246000 covered certain 2006-2007 S2000s built January 19 through November 13, 2006, whose brake booster may not hold vacuum, reducing brake assist. That is a booster issue, not a caliper one, but a hard pedal on those cars should be checked against the recall before chasing calipers.

Frequently Asked Questions

Why is only one of my S2000's inner pads worn out?

That almost always means that caliper's guide pins are sticking, so the caliper cannot slide to pull the outer pad in. Clean or replace the pins and boots when you replace the pads, and check the rotor for heat damage.

Can I push the rear caliper piston back with a C-clamp?

No. The rear piston houses the parking brake screw and must be rotated clockwise until it sits flush, with its cross-shaped groove aligned to the nub on the back of the inner pad.

What brake fluid does the S2000 use?

Honda specifies Honda Heavy Duty Brake Fluid DOT 3. DOT 3 or DOT 4 from a sealed container is acceptable only as a temporary measure, and DOT 5 should never be used.

Should I rebuild or replace a sticking caliper?

If only the guide pins are dry, servicing them fixes it. If the piston is pitted, leaking or seized, a replacement caliper is the reliable fix and saves time over a rebuild.

Is a big brake kit worth it on an S2000?

For street driving, healthy stock calipers with good pads, rotors and fresh fluid are enough. For regular track days, a kit like the Brembo GT-S adds heat capacity and pad area, but check wheel clearance first.

Was there a brake recall on the S2000?

Yes, for the booster rather than the calipers: NHTSA campaign 13V246000 covered some 2006-2007 models whose brake booster may not hold vacuum. A Honda dealer can check whether your VIN is included.

Sources

1. Honda S2000 Owner's Manual, Brake and Clutch Fluid - fluid spec, DOT 5 warning, low-level meaning, time-based replacement
2. NHTSA recall data, 2006 Honda S2000 - campaign 13V246000 brake booster vacuum recall
3. ADVICS: Troubleshooting Caliper Slide Pin Sticking - symptoms, causes and fix for sticking guide pins
4. HowTune: Change the Rear Brake Pads on a Honda S2000 - rear piston rotated clockwise, groove and pad nub alignment, release parking brake first
5. Brembo: Choosing the Right GT Kit - GT kit contents and GT-S caliper features
6. DBA 4000 Series Brake Rotors - Kangaroo Paw vanes, Thermal Stability Profiling, T3 slots