I have a break leak it would seem that is proving to be hard to find. The front reservoir is dry,(closest to the radiator) does anyone know if that is the front or rear brake section? looking at all the wheels I do not see any signs of a leak but it is leaking. I have not taken any wheels off yet though.. its 11 out today

Found the leak, it's in the main line for the rear breaks right where it goes through the frame and connects to the rubber line..Hopefully it is just loose and not rusted through

 

Does breaking a leak make it better or worse?

There are semi-separate portions of the reservoir. If you get the reservoir cleaned up, you may be able to see more fluid in the front or rear sections. The larger of the two sections will be for the front brakes; smaller for the rear.

The line to the rear follows the driver side frame rail from the firewall back to above the rear axle. You'll need to inspect it along the way back. This line likes to rot out anywhere from directly in line with the back of the front doors to back at the rear axle.

The fun part after you find the leak and make the necessary repairs is going to be bleeding the master cylinder. Once you get air in there, it can be a real pain to get it out.

You'll need to make up a short set of lines (can be rubber with the appropriate fitting to seal up to the outlets on the master cylinder) that will reach back up into the reservoir. Then you'll be able to pump the brakes until there are no more bubbles coming out of those lines in the reservoir.

After that, you'll need to bleed the lines & calipers (or cylinder depending on year).

 

On my '98 Blazer 4x4, the front reservoir is the rear brakes. Mine leaked just under the firewall, on driver's side. Line rotted on the frame rail. I replaced that full section with three separate pieces, from firewall to rear axle.

Also replaced the vertical pipe that goes from the ABS (?) and the horizontal line on the frame rail. Took a while to hand form the spring-coil section. Had to re-use the flare fitting at the ABS (and flare the pipe).

 

one way to tell, usually on older vehicles, is the one with the bigger brake line going to it is the back brakes but thats not always the case anymore

 

Thank you guys for the help, I got the truck fixed. Had to patch about a 6 inch section and gravity bled the system..