97 blazer braking problem----HELP

I have an 97 s-10 blazer LT. The brake pedal has been getting very firm recently and have check vacuum lines to no end. Today I was at stop light and car was wanting to die, had to put in neutral and limit brake pressure to get home. When brake pressure is applied car wants to idle rough and die, other than when brakes are pressed and at a stop, runs like a champ!!

--No Codes----


Vacuum gauge test seems fine, carb cleaner spray on vacuum lines and no abnormal idle or rev.

Anyone out there have any ideas.. Thanks

Check brake booster for losing vacuum.
MT

not sure how to check other than with vaccum gauge and carb cleaner for leaks. Is there any other way to do it or the right way to do so with vaccum gauge?

is there a check valve on this booster, napa says after 92 there isnt. If there is one how do i check that?

All vacuum brake booster have check valves.
Hinda hard to hook a vacuum gauge to the booster.
Listen for vacuum leaks.