MG Midget Brakes: Your Essential Rebuild Guide

For any classic car enthusiast, ensuring the safety and reliability of your beloved vehicle is paramount. The MG Midget, a quintessential British sports car, offers an exhilarating driving experience, but this can only be truly enjoyed when its braking system is in peak condition. Over decades, components wear, seals perish, and efficiency diminishes. A comprehensive brake rebuild isn't just about replacing worn parts; it's about restoring confidence and maintaining the authentic feel of your Midget.

Whether you're tackling a full restoration or simply addressing spongy pedals and reduced stopping power, understanding the intricate parts of your MG Midget's braking system is the first step. This guide will walk you through everything you need to know, detailing the components required for a thorough and effective brake system overhaul, ensuring your classic is as safe as it is stylish on the open road.

Understanding Your MG Midget's Braking System

The MG Midget's braking system evolved over its production run (1961-1979), primarily transitioning from front drum brakes to front disc brakes. Regardless of the year, the fundamental principle remains: hydraulic pressure generated by the master cylinder pushes fluid through lines and hoses to activate calipers (front disc) or wheel cylinders (rear drum), which then apply pressure to pads against rotors or shoes against drums. A full rebuild typically involves inspecting and replacing components in all these areas, ensuring a cohesive and responsive system.

The Heart of the System: Master Cylinders

The brake master cylinder is arguably the most critical component in your Midget's braking system, converting your pedal input into hydraulic pressure. Given its age, a failing master cylinder is a common culprit for a soft or spongy brake pedal. Midgets often feature a dual brake and clutch master cylinder, combining both functions into one unit.

Master Cylinder Variations by Year

• MG Midget Brake Master Cylinder 61-63: Designed for early cars with front drum brakes, this unit (Item #: L39121) is a dual brake and clutch master cylinder.
• MG Midget Brake Master Cylinder 63-66: For cars equipped with front disc brakes, this dual unit (Item #: GMC112) provides the necessary pressure.
• MG Midget Brake Master Cylinder 68-79: Later models utilise a different design (Item #: L4222-745).

Master Cylinder Rebuild Kits and Hardware

Sometimes, the cylinder housing itself is sound, but internal seals have failed. Rebuild kits offer a cost-effective solution:

• MG Midget Brake Master Cylinder Kit 63-66: Specifically for the 1098cc engine, 3/4 bore cylinders (Item #: LSSB717).
• MG Midget Brake Master Cylinder Kit 68-79: For original cylinders of this era (Item #: 24-04005).
• MG Midget Brake Master Cylinder Clevis Pin 68-79: Connects the brake pedal to the master cylinder pushrod (Item #: CLZ514).

Brake Pressure Valve Rebuild Kit

Found on 68-79 models, the brake pressure valve (also known as the brake shuttle valve) distributes pressure and houses a warning switch. A rebuild kit (Item #: BAU1704A) ensures this critical component functions correctly.

Table: MG Midget Master Cylinder Components

Front Brakes: Discs, Pads, and Calipers

From 1963 onwards, the MG Midget adopted front disc brakes, offering superior stopping power compared to the earlier drum setup. Rebuilding this system involves several key components.

Brake Pads and Hardware

Your Midget's front brake pads are the friction material that presses against the rotors. Regular inspection and replacement are crucial. You have options here:

• MG Midget Front Brake Pad Set 63-79: Standard replacement pads (Item #: D84). One set covers both sides.
• MG Midget Front Brake Pad Set, Ceramic 63-79: An upgrade (Item #: GDB332) offering potentially less brake dust and improved performance. One set covers both sides.
• MG Midget Front Pad Cotter Pin Set 63-79: Essential for securing the pads (Item #: GBK1010). Four pins per set.
• MG Midget Front Pad Retainer Clip 63-79: Two required per car (Item #: 17H7963) to hold the pads in place.

Brake Rotors (Discs)

The rotors provide the surface for the pads to grip. They can become warped or excessively worn over time, necessitating replacement.

• MG Midget Front Brake Rotor, Disc Wheel Cars 63-79: For cars with standard steel wheels (Item #: BTA383).
• MG Midget Front Brake Rotor, Wire Wheel Cars 63-79: Specifically designed for vehicles fitted with wire wheels (Item #: BTA469).

Brake Calipers and Components

The calipers house the pistons that push the pads onto the rotors. Calipers can seize, leak, or suffer from corrosion. You can replace entire calipers or rebuild your existing ones.

• MG Midget Caliper, Left/Right 63-79: Complete replacement units (Item #: 17H9438 for left, Item #: 17H9439 for right).
• MG Midget Caliper with Stainless Pistons, Left/Right 63-79: An excellent upgrade (Item #: 17H9438S for left, Item #: 17H9439S for right) as stainless steel pistons are far less prone to corrosion and sticking than standard steel ones, offering enhanced longevity and reliability.
• MG Midget Brake Caliper Rebuild Kit 63-79: Contains the necessary seals and dust boots to refurbish one caliper (Item #: LSSB2601).
• MG Midget Brake Caliper Channel Seal 63-79: If you've separated the caliper halves (generally not recommended unless absolutely necessary), this seal is required (Item #: 17H7679).
• MG Midget Brake Caliper Piston 63-79: Two are used per caliper (Item #: L114713).
• MG Midget Brake Caliper Banjo Bolt 63-79: Connects the brake hose to the caliper (Item #: 11D5264).
• MG Midget Brake Caliper Bleeder Screw 63-79: Essential for bleeding air from the system (Item #: 3H2428).
• MG Midget Brake Caliper Bolt Lockplate 63-79: Secures the caliper bolts, often plated in silver cadmium (Item #: BTC114).

Early Front Drum Brakes (61-63)

For the very early Midgets, the front brakes were drums, similar to the rear. If your Midget falls into this category, you'll need:

• MG Midget Front Brake Shoe Set 61-63: One set covers both sides (Item #: BS44).

Table: MG Midget Front Brake Components (Selected)

Rear Brakes: Shoes, Cylinders, and Drums

All MG Midgets used drum brakes on the rear axle throughout their production. These components are just as vital as the front brakes for balanced stopping.

Rear Brake Shoes

The friction material for the rear drums:

• MG Midget Rear Brake Shoe Set 61-62: For early Midgets up to chassis number 13554 (Item #: BS46). One set covers both sides.
• MG Midget Rear Brake Shoe Set 62-79: For later models (Item #: BS88). One set covers both sides.

Rear Wheel Cylinders

These hydraulic cylinders push the brake shoes against the drum.

• MG Midget Rear Wheel Cylinder 63-74: (Item #: DWC120).
• MG Midget Rear Wheel Cylinder 75-79: (Item #: DWC178).

Drums and Associated Hardware

The brake drums enclose the shoes and cylinders.

• MG Midget Rear Brake Drum 61-79: The main drum unit (Item #: 2A7168).
• MG Midget Rear Brake Adjuster 63-79: Consists of one wedge and two tappets. Two required per car (Item #: 17H7618K).
• MG Midget Rear Brake Shoe Spring Kit 61-62: For early Midgets up to chassis number 13554 (Item #: BSK1). Covers both sides.
• MG Midget Rear Brake Shoe Spring Kit 62-79: For later models (Item #: BSK2). Covers both sides.
• MG Midget Rear Brake Drum Screw 61-79: Four required to secure the drum (Item #: SF604051).
• MG Midget Drum Lockplate 62-79: For cars with wire wheels (Item #: BTA493).
• MG Midget Brake Drum Plug 61-79: Seals the access hole (Item #: 2A7228).
• MG Midget Rear Brake Boot 63-79: Located on the back of the backing plate for the emergency brake lever (Item #: 17H8057).

Table: MG Midget Rear Brake Components

Connecting the System: Hoses and Pipes

Brake hoses and pipes carry the hydraulic fluid throughout the system. Over time, rubber hoses can degrade and crack, leading to leaks or a spongy pedal. Metal pipes can corrode, especially in the damp UK climate.

Brake Hoses and Washer Sets

Flexible hoses connect the rigid brake pipes to the calipers or wheel cylinders.

• MG Midget Brake Hose Set 61-63: For cars with front drum brakes (Item #: SPRITEBRAKEHOSE).
• MG Midget Brake Hose Set 64-79: For cars with front disc brakes (Item #: MIDBRAKEHOSE).
• MG Midget Stainless Steel Brake Hose Set 64-79: An excellent upgrade (Item #: SBK102, made by Goodridge). These provide a firmer, more positive brake pedal feel due to less expansion under pressure, enhancing overall control and responsiveness.
• MG Midget Brake Hose Washer Set 61-63: (Item #: WASHER KIT 1).
• MG Midget Brake Hose Washer Set 64-79: (Item #: WASHER KIT 2).

Brake Pipe Sets and Unions

The rigid metal lines that run throughout the chassis.

• MG Midget Brake Pipe Set 68-74: (Item #: GL5066).
• MG Midget Brake Pipe Set 75-79: (Item #: GL5061).
• MG Midget 3 Way Union for Rear Brakes 61-79: A common junction point for the rear brake lines (Item #: 3H2424).

Table: MG Midget Brake Hoses and Pipes

Essential Ancillaries & Control

Beyond the core hydraulic components, several other parts play a crucial role in the overall brake system, from activating brake lights to facilitating parking.

Brake Light Switches

These switches illuminate your brake lights when the pedal is pressed.

• MG Midget Brake Light Switch 61-67: (Item #: 51600).
• MG Midget Brake Light Switch 68-79: (Item #: 35896).

Brake Pressure Fail Switches

These switches detect a pressure differential between the front and rear brake circuits, indicating a potential failure and illuminating a warning light on the dashboard.

• MG Midget Brake Pressure Fail Switch 68-75: Located in the brake pressure valve (Item #: 64677381).
• MG Midget Brake Pressure Fail Switch 76-79: Also in the brake pressure valve (Item #: AAU2454).

Handbrake and Pedal Components

• MG Midget Handbrake Switch 76-79: (Item #: AAU2492).
• MG Midget Brake Pedal Return Spring 67-79: Ensures the brake pedal returns to its resting position (Item #: BHH2387).
• MG Midget Pedal Box Top Cover Seal 68-79: (Item #: AHA8073).
• MG Midget Pedal Box to Firewall Seal 68-79: (Item #: AHA8072).
• MG Midget Emergency Brake Cable 61-76: For models up to chassis #182000 (Item #: 2A7308).

Table: MG Midget Ancillary Brake Components (Selected)

Frequently Asked Questions (FAQs)

Q: Why should I rebuild my MG Midget's brakes instead of just replacing the worst parts?

A: A full brake rebuild ensures that all related components are fresh and working in harmony. Replacing only one or two worn parts might address an immediate symptom, but other ageing components could soon fail, leading to further issues and potential safety risks. A comprehensive rebuild provides long-term reliability and consistent braking performance, crucial for a classic car.

Q: What's the difference between standard and ceramic brake pads?

A: Standard organic or semi-metallic pads are common and offer good general performance. Ceramic pads (like Item #: GDB332) typically produce less brake dust, offer quieter operation, and can provide a more consistent feel across a wider temperature range. They are often chosen for a cleaner look and improved stopping power without excessive wear on rotors, making them a popular upgrade for enthusiasts.

Q: Are stainless steel brake hoses worth the investment?

A: Absolutely. Standard rubber brake hoses can expand under high hydraulic pressure, leading to a slightly spongy pedal feel. Stainless steel braided hoses (like Item #: SBK102) resist this expansion, providing a firmer, more immediate, and consistent pedal feel. This translates to better brake modulation and a more positive response, significantly enhancing driving confidence.

Q: Should I opt for calipers with stainless steel pistons?

A: Yes, if your budget allows. Original steel caliper pistons are highly susceptible to corrosion, especially in the damp UK climate. This corrosion can cause pistons to stick, leading to uneven braking, dragging brakes, or even complete caliper seizure. Stainless steel pistons (like Item #: 17H9438S) are far more resistant to corrosion, offering significantly improved longevity and reliability, reducing the likelihood of future brake issues.

Q: How do I know which master cylinder or brake hose set is correct for my Midget?

A: The key is to know your MG Midget's year of manufacture and whether it has front drum or disc brakes. As seen in the tables above, different components are specific to certain year ranges and brake configurations. Always double-check your vehicle's specifications before ordering parts. If in doubt, consult your vehicle's documentation or a specialist MG Midget parts supplier.

Conclusion

Rebuilding the brakes on your MG Midget is a rewarding project that significantly contributes to the safety and enjoyment of your classic car. By systematically addressing each component, from the master cylinder to the smallest cotter pin, you ensure a reliable and responsive braking system. The investment in quality parts, such as ceramic pads or stainless steel hoses and pistons, not only enhances performance but also extends the life of your brake system, giving you peace of mind on every journey. Remember, good brakes are not just about stopping; they're about control, confidence, and preserving the true spirit of your MG Midget.

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