`99 S10 Blazer noise
 

Not sure if this is the right area for this question. I have a `99 S10 Blazer with the 4.3 V6. There is a noise like a howling vacuum cleaner coming from the hose that runs from the manifold to the brake booster. I`m wondering if there is some kind of valve in that fitting or just what I will find when I pull this apart. Anyone ever experience this problem ? Thanks

Re: `99 S10 Blazer noise
 

sounds like a vacuum leak, hose or fitting is loose, cracked badly

Re: `99 S10 Blazer noise
 

I'd say the same. My 91 had a hose develop a hole on the underside that made a similar noise. The hose looked good from above but until I ran my fingers down the hose with the engine running I didn't know what the issue was. The hose simply had a 1/4 inch spot that rotted away.

Re: `99 S10 Blazer noise
 

Thanks guys. I`m going to check it out again tomorrow.