MGB GT

1965-1980 / Coupe / United Kingdom

All MGB GT problems All workshop problems

Critical Brakes

Seized Rear Brake Cylinders

Symptoms

One rear wheel locks or drags. The car pulls to one side under braking. A burning smell from one rear wheel after driving.

Cause

The rear wheel cylinders corrode internally. The pistons seize in the bore, either stuck extended (dragging brake) or stuck retracted (no braking on that wheel). Cars that sit for long periods are particularly susceptible.

Fix

Replace both rear wheel cylinders as a pair ($30--60 each).

Inspect the drums for scoring.

Cost: $100--250 for both sides including shoes if needed.

Cost mentioned in fix

$30Cost: $100

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// More MGB GT problems

Other known issues

Minor Brakes

Brake Master Cylinder Failure

A spongy brake pedal that sinks to the floor under sustained pressure. Brake fluid weeping from the master cylinder body or around the pushrod seal. Air in the system despite repeated bleeding.

Minor Brakes

Brake Servo Failure (Later Cars)

Hard brake pedal with dramatically reduced braking assistance. In the worst cases, reported by MGB Register members, fluid can leak internally into the servo canister -- the pedal feels normal until you press it, then all the fluid disappears into the servo and you have no brakes at all.

Minor Body and Structure

Sill Corrosion (Inner and Outer)

The outer sill skin bubbles, softens, and eventually perforates. In advanced cases, the outer sill crumbles when prodded. The inner sill -- the structural member -- rots from inside the box section and loses its load-bearing capacity.

Critical Body and Structure

Floor Pan Corrosion

Soft or perforated floor pans, particularly in the footwells and under the seats. Wet carpet is a telltale sign. In severe cases, you can see the road through the floor.

Minor Body and Structure

A-Post Corrosion

Rust at the base of the windscreen pillars where they meet the scuttle panel. This area can be invisible until advanced.

Minor Body and Structure

Door Skin Corrosion

Rust along the bottom edge of each door, working upward from the inside.

All MGB GT problems