Back up braking less when car not recently used
Have a '07 Honda Civic purchased in spring that has reduced braking on backing out of inclined driveway when car has been parked overnight; no problem noticed when car has been driven, and the car is put in reverse. Has only occurred in past several thousand miles. Told by local Honda dealer that has seen one other Honda. Told it may relate to breaking system not having enough vacuum, and that I should allow care to idle longer after starting. Don't know if this makes that much difference. Any thoughts or ideas?