Thanks, you were right. I tried it this morning with a completely cool engine and it bleeds as advertised.
Joe
'84 533i 255k

I vent mine with the engine cool & off, just make sure the resevoir cap is off & is topped off, only have to do it once. If you still have trouble, check the small return hose from the top of the radiator for blockage.

gale
ex 83 528 179k
92 735i 148k

Trying to bleed the coolant system as per Bentley's. Watched for fluid from bleeder valve but fluid level does not go down in the overflow reservoir. Tried it with engine running but all I got was air hissing from valve - no fluid. Temp got too close to red so I shut it down.

By the way, all I had done was replace the heater control valve (lost some coolant). Car never overheated prior to this.

Any help greatly appreciated.