91 s10 brake problems

my problem is when i start, The brakes will not work also runs kind of rough untill it warms up about 2 min. After that they will work but know its taking longer and longer for the brakes to work :banghead:

thanks for any help

91 s10 blazer 4x4 4.3L TBI

Sounds like a vaccum leak to me that seals it's self a little when it's warm.

You'll have to spray some WD40 on the vaccum hoses while it's running (cold) and when it suddenly revs up you'll know that you sprayed the leak

My guess is that it's the somewhere along the thick hose going to the brake booster.

Also sounds as if it mite be flooding, ( or getting to much fuel ) then as it warms up starts to clear out, or now burning the unused fuel, you might want to check your sensors and see if there is a problem with any that involve cold start and fuel, which I believe there is, maybe somewhere near the themostat housing.

Flooding wouldn't cause the brakes to function improperly. As already stated, sounds like a vacuum leak around your brake booster (big black cylinder on the firewall, driver side).

also if no vaccum leaks listen for a hissing sound when depressing the brake pedal the booster might be going out on ya

i agree, sounds like a brake booster going out.