Brake line routing diagram

[Joisey]

https://www.safercar.gov/staticfiles/safercar/pdf/EA11-001_closing_rpt.pdf   

 

I found this picture by accident after three hours of searching for a picture of the routing for the steel lines for my  2006 GMC Sierra 4wd.  Most other GM trucks would be the same or very similar.

 

I cannot find a way to post just the picture.  Open the link in Adobe Acrobat and go to page 14.  You can blow up the picture in Acrobat, around 300 % gives you a clear easy to read picture.  

 

lines run in order, from inside edge of frame (in plasic clips) or top edge of frame (in plastic clips) outward or downward.   If you run your lines in this order there is no crossing or bending of lines necessary.

 

Antilock brake ports:

 

1. top center port to right front brake

 

2. top left port to left front brake

 

3. top right port to rear brakes (actually, this line runs in it's own clip

 

4. bottom left port to master cylinder rear port

 

5. bottom right port to master cylinder front port

[no HD]

Thank you Joisey for posting this. I had the brake line rust through going to the right front last week. 99 Silverado 2500 (no HD), that I had bought in 2010. While replacing the line I noticed 3 other brake lines had already been replaced, which kind of surprised me a bit, seeing very little other rust under there.

It wasn't a fun job for sure, doing it on a creeper, with no lift. It was equipped with standard 1/4 inch tubing, but of course the flare nuts GM used are different from the flare nuts that come on the tubing that you find at the auto parts store. They did have the correct flare nuts in stock, I just had to cut the tubing to install them and re-flare them again. I had a double lip flaring tool.  I came straight out of the ABS controller with the new line  and ran it along the inside of the frame, ( it came from the factory coming out of the controller and going to the outside of the frame rail) and then pretty much routed it the rest of the way as it was from the factory.

I tried gravity bleeding the system first. When that didn't work, my wife helped me bleed them and now all is well.

I know I might have found the lines at the dealer with the correct flare nuts but I've found your usually better off in the long run not going there until your forced to.

[Joisey]

I'm glad that the diagram helped you.  I used the FineLines replacement lines the first time.  My original lines lasted 84K and I replaced them when they began to weep.  The FineLines lasted 36K and rusted thru.  My current set is made by Dorman and is stainless steel.  Fit is excellent, but I will never know how they last because the truck is going down the road.  Enough is enough.

 

Again, I am happy that the diagram helped you.

[Supreme Pizza]

 

 

     I usually just leave the old lines in place, and run the new lines along side them. You can spray the new lines with rust inhibitor once per year to keep them from rusting out. 

 

      To post the picture, try this: 

 

      Get the image on your screen, and then hold down "Control" and press "print screen" - which is located to the right of F12. Then open Microsoft paint, and select "Paste". Now just save the file to the desktop, and upload to the site. 

[Joisey]

I undercoated the first set of FineLine "lifetime" brake lines when I was sure there were no leaks.  Four years later they ruptured at the weld line.  One front driver's side and the main line feeding the rear brakes.  GM said there is no trouble with their brake lines, but on new trucks they are plastic coated, just like the two lines going to my rear wheel cylinders  on my 2006 Sierra.

 

I would have tried the 'print screen' idea, but alas, I have no MS paint.

[Supreme Pizza]

1 hour ago, Joisey said:

I would have tried the 'print screen' idea, but alas, I have no MS paint.

 

 

   Assuming that you have a smart phone, you could screenshot it and upload that way. Or take a picture of your desktop computer using the phone, and upload. 

 

 

[Supreme Pizza]

 

 

      If you right click on this image, you should be able to save it to your desktop. Then you should be able to upload it to the server. 

 

 

 

 

 

 

Edited July 15, 2018 by starman8tdc

[Jfayadjr]

Does anyone know the connector (nut) size that connects the brake line (right front) to the ABS module? 99 silverado 4wd

Edited September 23, 2019 by Jfayadjr

[davester]

I replaced almost all my lines with nylon-coated pre-bent steel lines from GM.  Still look good after 4 years and about 50k miles.  Only dumb thing about them is that GM didn't include the 2 lines going across the rear axle and they don't sell those lines separately anymore either...

[riverbanks]

It's a 5/16 to 1/4 reducer,brass,all parts stores have them,this way a 1/4 " line can be used with out touching the flare

[ChrisMatthews]

I have a 2006 GMC Sierra 4 x 4 Crew cab SLE. My lines are the tc04 727. They DO NOT go into the ports like everything I've seen says. The only diagram I gave found is from dealership or nemigaparts. It does not clearly show proper routing/port locations. I'm at my wits end here.

[ChrisMatthews]

I know from the only color code left my Rear Master cylinder line goes into the Top Middle port. I also know the line running to the rear (drums by the way) goes into the Top Right port. I am also fairly confident the Left front (Driver's side) line goes into the Top Left port. Other than that....HEEELLLLPPP!

Edited June 16, 2020 by ChrisMatthews
Addional info

[ChrisMatthews]

Going to drive around to look for another truck with intact lines.

[davester]

That would be your best bet.  When I did my lines years ago, I made sure to take pics of line routing (particularly along the frame rail from the front wheel to the abs controller, but also if it goes over/under various bits).

 

And be careful with the various clips holding the lines in place, as at least some of them are NLA new, and are very difficult to remove from another truck (say, in a junkyard) without also breaking them.

[ChrisMatthews]

Thanks Dave. Clips were pita, but patience and determination won in those. I took pictures, lots of them, trouble is the lines twist over the frame by the firewall. Also the pictures I took help quite a bit, however it only takes 1 out of the bunch to mess you up. I planned on paying close attention near the ebcm, but the lines snapped like dead branches. Looked at several trucks, all a bit different. I did gain perspective on the lines going through the clips though. Haven't yet determined if that helps me or not yet.