What is your question?
Symptoms: hard idle, engine sometimes stops when returning to idle, revs when brake applied/released in idle, engine bogs down when returning to idle, hissing sound near break booster (cannot hear inside the cabin)
Brake booster check valve was bad, so it has been replaced. Hose does not seem to be leaking. Tried clamping down on brake booster hose, and the problem got worse (engine bogged down and stopped after gas applied), but engine no longer revved when applying/releasing the brake. Symptoms seem to indicate a big leak, so I tried to find it using water and a spray bottle. Did not find anything. I am afraid to use starter fluid due to inexperience and no fire extinguisher. No brake fluid leak. No/minimal issues braking.
I have a 1999 Chevy S10 pickup with the v6.
Had the fuel pump and filter replaced last year after I broke down. This vacuum leak has been present since before that time, but has gotten worse.
Any ideas on how I might go about definitively diagnosing the issue?
What makes this problem better or worse?
Used to be worse when engine is cold, now it is constant.
How long has your 1999 Chevrolet S10 had this problem?
At least 3 years, worsening.
