Hi,
my V 70 /1999 TDI 2.5brake pedal becomes hard whenI use brakes a lot intraffic jamDOWNHILL.

It happens only downhill. Nothing simmilar when car is horizontal or goes up.What is the problem?

Thank you in advance

 

Also harder engine noise appears when brake padal is pressed. Looks like engine is loaded more at 800-1000rpm

 

Wo w never heard of that before.