Brakes

:runaround:I have a 1989 Silverado with a 305 engine, 4WD, automatic trans. About a week ago I started to hear a "Hissing" sound everytime I pumped the brake pedal, the sound only happens when the truck is running and it became progressively harder to stop the truck. I changed the pads (they were very worn) thinking that was the problem. I finished the job and the truck stops better but it's still making the "Hissing" sound and still doesn't stop as it should, it stops better but something is still not right. It has plenty of DOT3 and I never compromised the system during the pad change and there is no fluid under it. does anyone have any ideas as to what the problem might be? Any help is greatly appreciated. Eric

:runaround:I have a 1989 Silverado with a 305 engine, 4WD, automatic trans. About a week ago I started to hear a "Hissing" sound everytime I pumped the brake pedal, the sound only happens when the truck is running and it became progressively harder to stop the truck. I changed the pads (they were very worn) thinking that was the problem. I finished the job and the truck stops better but it's still making the "Hissing" sound and still doesn't stop as it should, it stops better but something is still not right. It has plenty of DOT3 and I never compromised the system during the pad change and there is no fluid under it. does anyone have any ideas as to what the problem might be? Any help is greatly appreciated. Eric

a hard brake pedal with your hiss sound is most always the brake booster..this is the large metal object that the master cylinder is mounted on...vacuum goes to this and when the pedal connection seal cracks you get this noise with the hard pedal..usually 10-15yrs these fail.

Thanks, I appreciate your help, One last question, is it a hard fix or something a back yard machanic can handle?

Thanks, I appreciate your help, One last question, is it a hard fix or something a back yard machanic can handle?

with basic tools and a repair manual to guide you throw this , it is a 1hr job..the newer the vehicle and with more options it can be hard to get at some connections ..

Thanks again, I have the manuel and I have access to an Auto Hobby shop where I can get some help and some advice.