Stop iOS 7 MKMapView from leaking memory

I had faced the same issue and (thanks to Stackoverflow) fixed it by changing MKMapType in viewWillDisappear and deallocating/setting its delegate to nil.As it still sends message to delegates.
This is documented in MKMapViewDelegate Protocol Reference:

Before releasing an MKMapView object for which you have set a
delegate, remember to set that object’s delegate property to nil. One
place you can do this is in the dealloc method where you dispose of
the map view

.

-(void)viewWillDisappear:(BOOL)animated{
  [super viewWillDisappear:animated];
  [self applyMapViewMemoryFix];

}

- (void)applyMapViewMemoryFix{

switch (self.mkMapView.mapType) {
    case MKMapTypeHybrid:
    {
        self.mkMapView.mapType = MKMapTypeStandard;
    }

        break;
    case MKMapTypeStandard:
    {
        self.mkMapView.mapType = MKMapTypeHybrid;
    }

        break;
    default:
        break;
}
self.mkMapView.showsUserLocation = NO;
self.mkMapView.delegate = nil;
[self.mkMapView removeFromSuperview];
self.mkMapView = nil;
}

hope this helps