I've looked through as many old messages as I could but my problem hasn't quite been addressed. I have a 1989 Audi 200 turbo, non quattro.It has 160,000 kms and was stored for 6 years. I bought it this past February and it was great as long as the weather was cold. Now that it's hot out the front driver's brake locks on when the car gets hot. Only that one brake. Basically, as long as the temperature stays at 90 celsius it's okay but if it gets up to 100 celsius the brake will engage. It will even engage while the car is sitting idling, if it gets warm enough. The rotor hasn't warped -yet. The brake fluid has been flushed twice, the hydraulic oil has been replaced once, the calipers have been cleaned twice, and the accumulator has been replaced. Nothing has helped. While the brake is engaged the brake pedal will either be stiff or go almost to the floor. And if I'm on the highway it will suddenly release and then slowly lock on again. Suggestions by several mechanics at this point is the ABS control unit. The idea is that it sits close behind the rad and is getting too hot. I should mention that the fan doesn't come on until the car is at 100 celsius and only stays on for about 15 seconds, not enough to cool the car down. Any ideas? Is it a brake problem or a cooling problem? Or both? And what would you suggest for a repair? The ABS unit is $2800 brand new but I've found a used one for $250. I'm hesitating to buy it, though, after spending over $600 for the accumulator and just wasting my money. This has been going on for the last few months and I even had to buy a beater car to have something to drive until someone figures out what's wrong with my Audi. Any help would be very much appreciated!