For over a year I was driving this Civic with a slipping transmission.
Finally, a couple of weeks ago it gave up and wouldn't run at all. I went
back to where I had left it parked and was able to drive it slowly a mile
home. I knew I could drive it over to the nearest Lee Miles Transmission
shop, which I did a day after limping home with it. I was told it might run
about 1400 to fix the tranny. After I took it in and they had it apart it
turns out the price would be about 1700 to fix it. I waited almost two
weeks while I was told they had to send away for parts they couldn't get
locally. When I talked to the manager on the phone he told me the
transaxles were bad and he would replace them for 75 bucks each, which I
thought would relieve me of having to do it as I knew the boots were ripped.
I like this car, old as it is, so much that I was willing to spend money on
the tranny. It only has 90k miles on it.
Today I finally got the car back and paid the bill of $1,999.15 and drove it
home. They told me a couple of things I already knew, such as the exhaust
system leaked and the battery was oversize for the car. I had planned to
put in a new exhaust pipe after the tranny was fixed. They also told me the
brake booster didn't work. That became obvious as I drove it home with a
hard brake pedal. I popped the hood and looked to see if the vacuum hose
had merely come loose. I found a bolt stuck in the engine side vacuum hose
which I pulled out and connected the hose back to the booster. I drove away
and the booster still did not do its job but also I stalled and the engine
wouldn't run properly. I had to restart it several times to get around the
block.
My question is: what does my booster (which worked fine when I took the car
in) have to do with my transmission and what could they have done to damage
the booster while they had it in the shop? Why won't the engine run
properly without the booster vacuum hose being plugged?
If someone can tell me what might have been done to the engine I would
appreciate some input. Thanking you in advance for your help.

Derek