Had a leak from the brake fluid reservoir and also had soft squishy brakes (new to me D2 - 95K miles). Decided to solve the leak in hopes that solving the leak and bleeding brakes for air in the lines would solve my squishy/soft brake problem. Replaced the reservoir and seals with the kit from Atlantic British. Leak gone. Bled the brakes - almost no air to bleed out. Test brakes after all this and they are still squishy/soft - no change. When the car is off, brake is firm on press...when the car is on, brakes are squishy/soft. If I start car when foot on firm brake, the brake turns to soft/squishy when started. Ai tells me its the brake booster? I feel like I'm on the road to replacing the Master cylinder/brake booster/brake lines, etc. etc. Any help/Advice appreciated to reduce my pain and spend - thx!

 

Ideally you should use something like a Nanocom to bleed the ABS portion, but I think you can accomplish most of the bleed by jumpering the contacts at the ABS pump relay.

 

You can test booster, connect hand vacuum pump to booster and pump down. It should hold vacuum.