The brake pad warning lights came on in yellow.my mechanic replaced front pads rears didnt need doing.The yellow coloured warning light is off and has been replaced with a big red symbol and exclamation mark which beeps then goes off.I pressed the spanner button on the dash and it says brake fluids low and hydraulic fluids  but they aren't .any suggestions?

Welcome to the forum Rob :) 

youll find the members on here are a friendly and helpful bunch :) 

it sounds to me like a faulty sensor or a bad earth. Have you had a diagnostic check carried out on your a4? 

Cheers

steve 

Hello Rob,

Not sure if this may help, but I would first check the connections on the top of the brake master cylinder. These may have been disturbed/strained when the mechanic most likely would have taken the top off during the brake pad renewal. 

Kind regards, 

Gareth.