Seems to be a lot of confusion here, or they are just different among certain years and/or models:

These all say bottom left port on ABS (when looking from front to rear) should be rear M/C port, which is front brakes:
ABS Systems 101
http://www.justanswer.com/chevy/5hqb...line-goes.html
http://www.justanswer.com/chevy/3wjz...ake-lines.html

This one has different labels in the pic than he explains below it:
2003 checy avalanche...need brake line routing from master - Fixya

If the lower hole further from the frame rail should be the rear port on M/C which is front brakes, it is, so I'm lost as to what my problem can be...

 

When you were saying front/rear in the section I quoted, were you referring to those brake systems, or the ports on the M/C (which are obviously opposite)?

Thanks! Jeff

 

As I stated above in my quote is correct for a 1500 truck. Neither trucks have an external proportioning valve.

2 in from the MC and 3 out to the brake system.

 

I described it looking up from underneath the truck as the picture was shown.

 

This is as I described it. The red on the attached picture indicates a frame rail.

 

To update, I did neither. I pumped brake fluid in through the bleeders. I did each caliper until the level rose in the M/C. No air when I tried bleeding afterward, no ABS problems. Rock hard pedal. I am sold on the back-filling method.

 

Not having much luck getting these on the ABS unit I an get one one MC line but not the other. Tried about every combination I can think of over under but nothing I do alows me to start both lines. one just won't reach on a old 2000 body style LT Set. Wish I had just bought the OEM set now, as they would have been on the truck and back on the road. Thought while I put the fule line set on I would take the time to change them as the body was up alredy. What a bad call it has been so far. Just thought I would let all know. Either way I go the line either mc1 or mc 2 doesn't seem to mater comes up about 1/4 inch short. Line set was from Rock auto. 2 days and still at it. off and on. 1/4 inch of extra tube would have went a long way on the front MC line at the ABS unit.

 

2000 express 1500, do you know the size of the fittings that go on the lines, I need the 2 going into my abs from master, then each line running to the front rubber caliper hoses(each side)? Thanks