MG T-Series ArchiveMGT-SERIESMG T-Series

Engine & Mechanical

The T-Series Brakes: Drums, Adjustment and Common Faults

IntermediateThe T-Series braking system is simple, effective drum braking — and, kept in good order, perfectly adequate. But it is old technology that relies on regular adjustment and fresh fluid, and it has a handful of familiar faults. Here is how it works across the TC, TD and TF, and how to keep it safe.

The T-Series braking system is simple, effective drum braking — and, kept in good order, perfectly adequate for the performance. But it is old technology that relies on regular adjustment and fresh fluid, and it has a handful of familiar faults. Here is how the system works across the TC, TD and TF, and how to keep it safe.

The system

The post-war T-Types use hydraulically-operated drum brakes on all four wheels, with a master cylinder fed from a reservoir and a wheel cylinder expanding the shoes against the drum at each wheel. It is a straightforward single-circuit system — which means there is no back-up if it fails, so condition is everything.

Adjustment

Drum brakes need periodic manual adjustment as the shoes wear, to keep the pedal high and the braking even. The T-Series has adjusters at each backplate; set them by the book — jack the wheel, tighten the adjuster until the drum locks, then back it off until the drum just spins free. Even, correct adjustment all round is what gives a firm pedal and a straight stop.

Fluid and hydraulics

Brake fluid is hygroscopic — it absorbs water over time, which lowers its boiling point and corrodes the system from within. Renew it every couple of years. A spongy pedal usually means air in the system (bleed it) or a failing master or wheel cylinder; a pedal that slowly sinks to the floor means a leaking master cylinder. Seized or leaking wheel cylinders, perished flexible hoses and a tired master cylinder are all age-related jobs to do, not defer.

Common faults

  • Pulling to one side: often a seized wheel cylinder or adjuster on one side, a contaminated shoe, or a collapsed flexible hose acting as a one-way valve.
  • Oil or grease on the shoes: from a leaking hub seal or a weeping rear axle seal — cure the leak and fit clean shoes, do not just clean the old ones.
  • Grabbing or juddering: worn or contaminated shoes, or drums worn out of round.
  • Seized adjusters and a slack handbrake: free them off and lubricate; the handbrake works on the rear drums and goes slack if the mechanism is neglected.

Upgrades

Many owners fit the period-style front disc-brake conversion to the TD or TF for stronger, fade-free braking — a sensible, in-keeping upgrade if you drive the car hard or in modern traffic. That said, a well-maintained drum system stops these light cars perfectly well.

Always confirm adjustment figures and fluid specifications against the workshop manual for your model.

*Written for the T-Series Archive. Brake specifications vary by model — confirm against the workshop manual, and treat brakes as safety-critical.*