94 accord wagon

im not a frequent accord guy so bare with me, my friend called me saying his brakes went out, and..... they did. i checked it out and there is not brake fluid in it. the engine surges when its warm, im assuming due to empty brake booster or something related, the fluid all came out on the driver side of the engine bay. problem is i didnt get to see it spew out to see where it was coming from and when it did come out it was in a hurry so it didnt exactly look like one place leaking. i checked the brake lines outsie the bay and they r all fine. i looked over the lines from the abs module and they seemed fine, so did the booster lines. im goin to see if i can fill it with brake fluid and see where it comes from and hopefully pinpoint it but if i cant r there any things i should check? does this sound like anything familiar? any advice is appreciated.

 

Likely the brake master cylinder.

 

where exactly is that

 

It is the metal part that has all of the brake lines going into it plus the plastic reservoir that holds the brake fluid. #1 in the pic below.

 

Ok how do I prove that it is in fact this and not other things ? Just run fluid through it ?

 

Clean up all the old fluid.

Add brake fluid to the reservoir, then locate the leak.