I need a diagram for the brake system on 1985 gmc truck 2x2.

SOURCE: GMC truck exhaust diagram

GUESSED AND IT WORKED!

SOURCE: where do i get a FREE diagram of a 1985 gmc

believe it or not a lot of local libarys carry tech manuals. no garrentee but worth a shot

Testimonial: "what a dummy, i forgot about the library.. thanks...."

SOURCE: 1999 gmc sierra brake line diagram

I would join autozone.com for free and they have most any diagram you will need for free for this vehicle

SOURCE: Need to see diagram on where brake line is located

give these websites a try www.alldatadiy.com and www.autozone.com if all fails stop by your local GM dealership in the parts department and they be able to print you off the pictures and diagrams you will need wish you the best of luck Michigan Man.

Testimonial: "Thanks Michigan Man I will follow your advice"

SOURCE: Where to find diagram to install whole rear brake lines

I don't know about a diagram. Just buy some 1/4 inch brake line and run it as close to the original as you can.