HYDRAULIC SYSTEM OVERHAUL Any components of the braking system which show signs of fluid leakage should be overhauled or replaced immediately. Only units which appear satisfactory after careful examination of the components should be reassembled using new seals. Any unit which has damaged bores or pistons must be discarded and replaced by a new unit. If in any doubt, replace the unit - your safety could depend on it!
When overhauling any components of the hydraulic system, this must be carried out under conditions of scrupulous cleanliness. This cannot be over-emphasised. Clean all dirt and grease from the exterior of components before removal or dismantling.
Wash all components in methylated spirit or clean brake fluid only. Do not use any mineral-based oils, such as petrol, paraffin or carbon tetrachloride. All internal passages should be blown out with compressed air.
Inspect the piston and cylinder bore surfaces carefully for any signs of scores, ridges or corrosion pits. The unit must be discarded if any of these conditions are present.
Only new seals should be used when reassembling. These are generally available in the form of a repair kit containing all the necessary parts required for overhaul of a particular unit.
All seals, even when new, should be inspected carefully before fitting. Discard any seal which does not appear perfect, no matter how minute the blemish may appear to be.