brake booster question

[lmpbzkt492]

today i found a hissing noise coming from around the brake booster area and after some listening have concluded it is coming from the brake booster. if i pinch off the hose going to the booster the hissing goes away. does this mean my booster is bad or is it just the valve that comes off the booster that the hose connects to? Thanks

 

[lmpbzkt492]

any ideas??

 

[7-UP BILL]

Does your pedal feel any different? If it starts getting hard, it's most likely losing vacuum. If you pinch the line going to it and the hissing stops, the diaphram inside the booster is probably shot. What year is car? I have a booster in great shape if your interested. It's from a '90 and had 15k on it when I removed it.

 

[jrichker]

A small rubber hose used as a stethoscope to listen & locate the leak may be helpful. The rubber grommet that the brake booster mounts the vacuum check valve in is a known source of leaks. Use the rubber hose trick to see if the leak is in that area. If it is, the grommet is cheap, only $2-$3 to replace it.

 

[lmpbzkt492]

i guess i could start with the check valve first being that it is the cheapest. would any auto parts store carry that part? the thing that im the most mad about is that i just had the booster replaced a little over a year ago. but if i pinch the line and the hissing goes away im guessing it is most likely the booster and not the valve

 

[old_blue]

have you checked the hose for cracks?? that would be my first area as those are hardly ever replaced and are usually the culprit. you may be pinching it off right before the crack is.

 

[RYC CUKR]

Get a can of TB cleaner and lightly spray it around the booster, hoses and anywhere else you suspect the leak may be. If the engine idle increases when you spray a certain area that is where you leak is. This is how I check for leaks after doing an intake swap.

 

[Shakerhood]

I would check the Vacuum Tree and the Hose to the Booster