What a marvellous help, many thanks I will investigate further.
One further question however - how do I flush the system?
Hi,
Forgive me for possible overkill..but I have found it always best to give a complete explanation than a short and sweet one.
Automobile hydraulics (clutch and brake) use special fluids. The different types are designated as DOT 3, DOT 4, DOT 5 and DOT 5.1. DOT 5 is silicone based and the rest are borate ester based. (The higher the number the higher the boiling point.) DOT 5 is NOT compatible with the others and switching to and from DOT 5 can cause grave problems. Avoid DOT 5 like the plague. However, once used, you must continue to do so. You cannot safely switch back without changing every bit of rubber in the system.
All brake fluids are designed to resist the absorption of water. That ability fades over time. Brake fluids (in clutch or brakes)should be changed once every 2-3 years depending on how damp your climate is.
Flushing a hydraulic system is simply a term for recylcing out all the old fluid and putting in new. For the clutch, it is done by opening up the system at the clutch slave bleeding nipple and pumping the pedal until the fluid runs a very light amber.
I do mine by emptying the clutch reservoir with a large mechanic's syringe, I then refill the reservoir with fresh brake fluid. I then place a 7/16 spanner over the clutch slave nipple and loosen it a bit until I can open and close it with very little movement.
I then attach a flexible clear tube over the nipple and place the other end in a clear bottle (big jam jar will do) that is filled enough with brake fluid to submerge the end of the tube.
I then open the nipple so the fluid can flow and someone slowly pump the clutch pedal while making SURE the reservoir remains full by topping it up. (If you don't keep the end of the tube submerged OR the reservoir full you will be pumping air into the system.)
You will see the dirty fluid come out and (if your system had air) bubbles in the bottle. When the fluid runs clear and the bubble stop, tighten the nipple enough to close the system, remove the tube and tighten the nipple snuggly.
WATCHPOINT Though innocuous looking, hydraulic brake fluid of any type is the most dangerous fluid for health in the car. If some drops on the car paint, clean it off immediately..it strips paint with great glee. If some of it falls on you or your clothes, clean it off, it strips skin with equal glee.
Lorne
