Brake Master leakage, a tale of woe

[Snotcycle]

Hey all, for about 4-5 months I have had a very mysterious brake fluid leak. Sometimes i would lose a whole reservoir of fluid overnight and come out to squishy brakes from air getting in the lines. Other times i would not lose any fluid for over a month. I have never found any puddles of fluid or leaked fluid on any part of the car, brakes, driveway, etc. This was a scooby-doo mystery type situation.

During my blacktop motor swap my car sat for a few months and naturally, i lost all the brake fluid. So 5 days ago i filled the fluid up and bled everything til it was legit. Then yesterday i go to drive the car an realize all my fluid is gone again, pedal is squishy but i have brakes if i push the pedal far enough. So i fill up the reservoir again and decide I'm only going for a short drive so i will do it without bleeding. After driving literally a quarter of a mile, my low brake fluid light comes on again, but brakes seem the same in feel so i just drive slowly and carefully. I filled up the fluid again today and while waiting for the car to warm up i pump the brakes to feel it out; this is when things got interesting. I push the pedal down and there is very little resistance til i get close to the floor, then there is a weird resistance and feel like when you are bleeding the brakes and pushing fluid down the lines. Instantly my idle drops to 400-500 RPM and i have to give it gas to keep the car running. As i sit there trying to figure out what just happened, white smoke begins pouring from the tail pipe smelling unlike anything i have ever smelled coming from a tailpipe (IE not coolant, oil, fuel, or burning engine). Aside from the smoke and the low, rough idle, everything seems OK. I drive a few blocks around the neighborhood to figure out if my engine is borked or whats going on until it hits me.

The fluid is leaking out of the master into the brake booster; and has now filled my booster enough to begin getting sucked up the vacuum line into the manifold!

I pull over and disconnect the booster and sure enough a steady stream of brake fluid is dripping out of the vacuum hose. Luckily I had a spare vacuum nipple cap with me. Restarted the car without issue, the smoking stopped almost immediately but the burning brake fluid smell remained to rest of the ride. Drove the 4 blocks home with no power brakes and now there my car sits.

My questions are as follows:
1) I need a new master cylinder, does it make sense to get anything after market or should i just get OEM?
2) Do i need to replace the booster as well?
3) Do you guys think there was any damage done to the engine or that my oil or other fluids could be contaminated from brake fluid being sucked in through the intake? (engine did not hydro-lock, appears to be running alright)
4) Anything else I need to worry about?

Car is an '85 GTS Coupe with a blacktop swap. brakes are stock except for drilled and slotted rotors and nicer pads.

Sorry for long post!

[mideng]

Get Aisin

I bought mine from torparts

[totta crolla]

Renew the Master cylinder and the booster.
The booster has a large rubber diaphragm that is likely to be affected by being soaked in brake fluid.
Oil and filter change just to be on the safe side.