MGB GT

1965-1980 / Coupe / United Kingdom

All MGB GT problems All workshop problems

Critical Clutch

Clutch Hydraulic Failure

Symptoms

The clutch pedal drops to the floor with no resistance. No clutch disengagement -- the car won't go into gear with the engine running. Fluid visible on the carpet (master cylinder leak) or on the bellhousing (slave cylinder leak).

Cause

The clutch master cylinder and slave cylinder use rubber seals that harden and fail with age, identical to the brake system. The copper hydraulic line between them also corrodes, particularly at the flare fittings. Forum members report that aftermarket slave cylinders with a flexible hose (rather than rigid pipe runs) make bleeding significantly easier.

Fix

1 Replace the master cylinder ($40--80), slave cylinder ($30--60), and the connecting pipe. Bleed the system. Tip from experienced owners: when bleeding, remove the slave cylinder from its mount and hold it higher than the master cylinder -
2 air bubbles rise, making the bleed much quicker. Cost: $80--180 for all new components

Cost mentioned in fix

$40$30Cost: $80

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// More MGB GT problems

Other known issues

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.

Common Body and Structure

Boot Floor and Battery Box Corrosion

The boot floor softens and perforates, particularly around the battery box (in cars with the twin 6-volt battery setup in the boot). Acid weeps from the batteries and eats through the floor pan.

Minor Body and Structure

Rear Spring Hanger Corrosion

The mounting points for the leaf spring rear suspension corrode, crack, or tear away from the body.

All MGB GT problems