Car sounds like its going to die when at stop...just started post repair (idle, brakes)

[agallan]

Hello, and thanks in advance for your help!
I recently had a mechanic replace my master cylinder because I had to put my brake pedal to the floor to brake. Everything seemed fine after he fixed it and the issue was resolved.
Within the next couple times I drove the car again, I had a NEW problem. First of all, the brakes got "soft" again (though not as bad as before...maybe some air got back in?). But more importantly the car sounds like it is going to die when at a stop. One time it did actually die at a stop sign, which is obviously a huge safety issue.. But most times it recovers after about 10 seconds of making the noise like it is about to turn off. Of note, car has always had a bit of a "tremble" to it when in park for the many years I've owned it, and has a bit of a fast idle. A bit of research makes me think maybe this is a vacuum leak. But why would this happen right after the MC was replaced? Do you think its related or unrelated. Car has about 105k miles. Thanks! - Alex

[Chris V]

Alex

I like to help you. I am sure all the people here would like to help you.

But it's impossible.

(((((((((((((((((((((((((WHAT YEAR, MAKE and MODEL?)))))))))))))))))))

And don't tell me the color of the car.

[agallan]

Well that was DUMB of me! Sorry, I promise I MEANT to put that in there.

2002 Ford Escort SE
105k miles

Would love your advice, thanks!

[Chris V]

The mechanic would have to remove your air intake pipe. Disconnect a few hose to get access to the mc.

A brake booster vacuum, alone would not cause the car to die or want to die.

I would take a closer look around your throttle body. Was the air intake pipe installed properly?

Look at all the side hose, any of them not installed properly?

[High_Plains_Retired]

Some of those brake booster vacuum lines are huge. That would be the first vacuum line I would check after a master cylinder R&R since it's right there near the MC.