47201-12800 Brake Master Cylinder For Toyota Corolla 1.8L 4720112800

Product Function Description

The brake master cylinder is a critical component of your Toyota vehicle's braking system. This hydraulic device converts the mechanical force of the brake pedal into hydraulic pressure, distributing brake fluid through the brake lines to activate the brakes at each wheel. For Toyota Corolla (E100/E110), Geo/Chevrolet Prizm, and compatible models, a properly functioning brake master cylinder is essential for consistent braking performance, reliable stopping power, and safe vehicle operation. The part number 47201-12800 has been verified as the OE number for these applications  and is also compatible with certain Mitsubishi models .

DIY Diagnosis Guide

How to Tell If Your Brake Master Cylinder Needs Replacement:

Look for these common signs:

1. Spongy or sinking brake pedal – Pedal feels soft or slowly sinks to the floor under steady pressure

2. Brake fluid leaks – Visible fluid near the master cylinder or under the vehicle

3. Brake warning light – Warning light illuminated on the dashboard

4. Reduced braking performance – Longer stopping distances or less effective braking

5. Contaminated brake fluid – Fluid appears dark, cloudy, or contains particles

💡 Quick check: With the engine off, press the brake pedal firmly. If the pedal slowly sinks, the master cylinder internal seals may be failing. Check the fluid level in the reservoir and look for leaks around the master cylinder and brake booster.

 Product Attributes

Installation Guidelines

Tools typically required:

• Flare nut wrench (for brake lines)

• Socket wrench set (metric)

• Torque wrench

• Brake bleeding equipment

• Brake fluid (DOT 3 as specified)

• Safety gloves and eye protection

General installation reference (always follow vehicle-specific service manual):

Important:

• Do not reuse drained brake fluid. Always use fresh fluid.

• Use DOT 3 brake fluid as specified for this vehicle.

• Some aftermarket versions may be supplied without reservoir . Transfer the original reservoir or purchase separately.

• If you are unsure about any step, consult a qualified mechanic.

 Installation Tips & Common Mistakes

The Mistake When Replacing a Brake Master Cylinder:

❌ Wrong: Failing to bench-bleed the master cylinder before installation, or not bleeding the entire system afterward.

✅ Correct:

1. Always bench-bleed the new master cylinder before installation – This removes trapped air from the cylinder itself.

2. Use a flare nut wrench – Prevents rounding of brake line fittings.

3. Bleed the entire brake system after installation – Follow the correct bleeding sequence (typically furthest wheel first).

4. Use fresh DOT 3 brake fluid – Never reuse old fluid as it may contain moisture and contaminants.

5. Check if reservoir is included – Some aftermarket versions may not include the reservoir . Transfer the original reservoir if needed.

⚠️ Remember: If the master cylinder is installed without proper bleeding, the brake pedal will feel spongy or go to the floor. A properly bled system results in a firm, consistent pedal feel.

Features & Functional Notes

Performance Notes:

• The master cylinder is a critical safety component that directly affects stopping performance.

• A failing master cylinder can cause a spongy pedal, sinking pedal under steady pressure, or fluid loss with no visible external leaks.

• The brake pedal should feel firm and consistent after replacement.

Package Contents

1 x Brake Master Cylinder Assembly (includes reservoir on most variants) . Note: Mounting hardware and brake fluid are NOT included unless stated. Please confirm compatibility with your vehicle model, year, and ABS configuration before purchasing.

After Replacement Still Having Issues?

Replaced the master cylinder but still having brake issues? Check these:

1. Is there air in the brake system? – Bleed the entire system again in the correct sequence

2. Was the master cylinder bench-bled? – If not, air may be trapped inside the cylinder

3. Are the brake lines properly tightened? – Loose connections can allow air to enter

4. Is the brake booster working? – A failed booster can cause a hard pedal, not a spongy one

5. Are the brake hoses in good condition? – Swollen or damaged hoses can cause pedal issues

6. Is there a leak elsewhere in the system? – Check wheel cylinders and calipers for leaks

 Related Product Recommendations

Brake Calipers – Inspect the front calipers for leaks, sticking pistons, or damaged dust boots. A sticking caliper can cause pulling, uneven pad wear, and reduced fuel efficiency.

Brake Pads – Inspect brake pad thickness. If pads are worn thin, replace them. Contaminated pads from brake fluid leaks should always be replaced.

Brake Rotors / Discs – Inspect rotors for scoring, warping, or uneven wear. Replace if worn beyond specifications. Warped rotors can cause vibration during braking.

Brake Lines (Metal Pipes) – Inspect brake lines for corrosion or damage. Rusted lines can leak and cause brake failure. Particularly important on older Corolla/Prizm models.

Wheel Cylinders (Rear Drum) – For rear drum brake vehicles, inspect the wheel cylinders for leakage. Leaking cylinders can contaminate brake shoes and reduce braking effectiveness.