Workshop Basics

Overhall your clutch hydraulics.

Ahydraulic clutch is a common and effective system. It allows maximum flexibility for the car designer to position the clutch release lever and the clutch pedal wherever they fancy. It offers easy clutch actuation that requires little or no adjustment as the clutch wears.

There’s just one problem: the system deteriorates with age. The rubber seals degrade and leak or swell. Air can find its way in, giving an unpredictable pedal that doesn’t always disengage the clutch. The glycol brake fluid used in clutch systems is hygroscopic, so it absorbs moisture and can corrode the cylinders or seize the pistons over time.

Rubber flexi-hoses can collapse internally, creating a one-way valve effect and causing the pedal to return slowly or the clutch to remain disengaged completely. Plastic flexipipes harden and split. Steel rigid pipes rust through and leak. Cylinders can seize solid if the car’s left standing – particularly the slave cylinder, which has a hard and dirty life under the car.

Routine maintenance will normally avoid such traumas, or at least ward them off for a long period of time. Give the clutch system a thorough visual inspection at every service. Check pipes for corrosion, flexi-hoses for deterioration and cylinders for leaks, crustiness and smooth operation.

Also make sure the protective boots of the cylinders are doing their jobs properly. Make sure the fluid’s in good condition. Discolouration suggests contamination or dissolving seals. Replace glycol (DOT 4) fluid at least every few years.

No matter what you do, though, an occasional overhaul of your clutch hydraulics is inevitable. If a classic’s been standing for a long period or has had a less then attentive previous owner, it’ll definitely be due a birthday. This guide will see it restored to perfect condition and should prepare it for years of trouble-free service.