Hello everyone.
Another issue came up with my truck. Driving it this morning, got out about 4 miles from my home and my breaks completely went out. Driving home wasn't fun.
My break fluid reservoir went completely empty. So I drove my other vehicle up to the store and bought more break fluid. Got home, put it in. it stayed up for about 10 min. Came back outside to check on it.
It was all gone. but no drips anywhere on any of the tires. I have no idea where all the liquid went or is going. Any idea where to look to trouble shoot?.

Thanks for any help.

 

If you see no signs of leakage at the wheels or the lines in between , fluid is likely leaking out the back of the master cylinder into the booster and going into the engine's intake via the vacuum line.. You can unbolt the master cylinder with lines attached for a look. You are looking a new master cylinder and complete system bleeding if that's the case.

 

If you drive where salt is used in the winter to control icy conditions,, you might look under the middle of your truck on the driver's side where the brake lines run to the rear of the vehicle. They are steel lines and rust through and leak . Most times the fluid will run along the line before dripping on down to the ground. The plastic clamps that secure the lines to the frame are where salt hangs around and does the most damage.
If that is what you find , get back to us and we should be able to guide the best way to handle this.