bleeding the radiator after replacing water pump
bleeding the radiator after replacing water pump
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carl24

Original Poster:

28 posts

206 months

Thursday 20th August 2009
quotequote all
ive just replaced the water pump on my 523i e39 and want to know how to bleed the system properly?? any ideas?

eliot

11,995 posts

284 months

Thursday 20th August 2009
quotequote all
You should try to obtain the TIS CD, which has the instructions. Assuming a 1999 e39 523 M52, if not tell us the exact year.
It says:
To ensure the cooling system is properly vented, it is absolutely essential to follow the steps below:
1. Undo cap but do not remove from expansion tank. This prevent excessive discharge of coolant from the expansion tank.
2. Turn on ignition.
3. Set heating controller to max. temperature.
4. Set blower to low level. This opens the heating valves and sets the auxiliary water pump in operation.
5. Run engine and briefly press accelerator pedal three to four times (approx. 4500 to 5000 rpm) to flush engine cooling circuit.
6. In doing so, do not run engine for longer than approx. 30 seconds; otherwise coolant will heat up and expand.
7. If the coolant level in the expansion tank drops in the process, top up the expansion tank to the max. cold fill level.
8. Screw on cap tightly and allow engine to warm up until thermostat opens.
9. Check coolant level. Pay attention to differing expansion tank designs.


If you have a Transparent expansion tank:
Allow engine to cool down before checking coolant level. Coolant temperature must not exceed 30°C. If ambient temperature exceeds 30°C, allow engine to cool down at least to ambient temperature.
Check coolant level and if necessary top up coolant to max. cold fill level (see marking on expansion tank).
Note:
The tank mark indicates the fluid level at approx. 20°C. Use recommended coolant only.


If you have a Black expansion tank:
Allow engine to cool down before checking coolant level. Coolant temperature must not exceed 30°C. If ambient temperature
exceeds 30°C, allow engine to cool down at least to ambient temperature.
Check coolant level and if necessary top up coolant to max. cold fill level (the ball on the float needle is on the same level as the top edge of the expansion tank).
Note:
The tank mark indicates the fluid level at approx. 20°C. Use recommended coolant only.


On my E39 540, there is a little air bleed screw next to the filler cap on the expansion tank - I fill the tank right to the top, remove the air bleed set the aux pump on (as desc. above) and wait until it draws all the water round and no air bubbles come out of the bleed, then I start the car up and follow the procdure (rev it up a couple of times to get the the pump primed) and then let the car warm up slowy, adding coolant and squashing the top hose to encourage air bubbles out.

Edited by eliot on Thursday 20th August 21:33

carl24

Original Poster:

28 posts

206 months

Thursday 20th August 2009
quotequote all
its a 1996 p reg

phelix

4,683 posts

279 months

Friday 21st August 2009
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And if you can do the whole thing with the car on a hill or ramps nose-up that'll speed the process.