Re:changing The Main Thermostat On A 2.5

[Little&Large]

Hello all.
I have been looking for the thread on changing the above-can anyone direct me too it as I can't find it.
What is the secret to bleeding all the air out afterwards?
Many thanks
Regards Rob

[techmanagain]

There does not seem to be any thread or file for you to read, but the method is simple enough:-
Using an old LHM plastic bottle or similar, cut off the base, leaving about 10" (25cm) below the neck. Wrap insulation or masking tape round its neck until it is a watertight seal when inverted into the neck of the spherical overflow/filler tank. After having located ALL the bleed points in the piping and the bleed point at the RH side of the radiator, and with the radiator drain tap at the base of the LH side of the main radiator closed, pour the cooling liquid into the filling cylinder you have just made. I use a 50/50 mix of de-ionised water and antifreeze; the water's cheap enough at motor factors and reduces the corrosion factor somewhat, I believe.
As the liquid starts to bubble out of the bleed screws and when they are discharging clear, bubble-free liquid, close them one at a time as the water level rises in the system. Keep the filling cylinder full at all times. Start the engine and raise its speed to a steady 1500 rpm. Keep the engine at this speed for three cooling cycles (fans starting and stopping)., and keep the filling cylinder full at all times. Switch off the engine and wait for it to cool RIGHT DOWN. In some mysterious way (!) the water level in the filling cylinder will all have vanished, so remove the results of your earlier workmanship for a later date and top to the level in the overflow/filler tank to about 2-3 cm above the halfway point in the tank.
How much fluid will be needed? I usually make up 10 litres of mixture and if any more is needed, I use 100% antifreeze. Any surplus is used for topping up at any later date.
RH and LH of course refer to directions as seen from the driver's seat.
As a practical tip, I can rarely reach the point when the fans cut in and then out again, so I make sure the temp gauge on the dashboard reaches as high as it will go and keep the engine speed at 1500rpm until no more bubbles appear in the filling cylinder.