Have Ford Questions? Ask a Mechanic for Answers ASAP
Hello and thank you for your question,The expert you requested is not online at the moment so I will help you, sorry for the delay.If you are not finding any external brake fluid leaks and have lost all the fluid it is possible the seal in the master cylinder blew and this would cause the fluid to be sucked into the vacuum booster and it could be sucked into the engine from there. Start first with making sure there are no external leaks and if none are found pop the master cylinder off of the booster and see if there are any signs of fluid on the back of it where it connects to the booster. If so then the master cylinder has failed. Post back if you need more help and or have more questions and we can work from there.