As with any poison, see if your dog will drink some milk, and please please please call your local vet and/or poison control!
Pray it wasn't a lot . But if he is not showing signs (sleeping a lot or vomiting ) chances r he didn't drink a lot.But I would encourage foods high in fat to decrease the absorption rate in his intestine and walk or run him to speed up the mobility in his intestine Foods like bacon with the grease , raw eggs in his food or even cooking oil, just add this to his food .Milk coats the stomach but will not stop absorption .Milk is good for corrosive types of poisons .But chances r if he didn't throw up he is most likely okay Watch for signs of kidney problems
Have this dog examined immediately. Brake fluid contains glycols, so it causes the same toxicosis as ethylene glycol ie anti-freeze. If seen right after ingestion there are some decontamination measures that can be done. The big concern is protecting against or if you wait long enough treating kidney failure. Do not wait for this to develop--the prognosis is better the earlier it is treated. If permanent damage is done your dog will be in chronic renal failure--this does not have a good prognosis in dogs.
I would get your dog to a vet ASAP .... There is no home remedies for poison they can do more then you can prob iv fluids and so for!!!
Take your dog to the vet... Or it will die from poison