please help, brake prlblem and orange triangle light

[gavinbing]

Hi there

please help

i have just bought this car a week ago

it has had a new servo before i bought it

when i bought it, the car was fine for a day and now when i put my foot on the brake i get a loud hissing noise and whistling until i accelerate and then it goes away

i have also just got the orange triangle on in the middle of the dash with engine system fix next service on it

this light only comes on occasionaly can anybody helop with the bakres or the light and could they be connected any help would be grateful

thanks