Brake Line Help

macky · December 4, 2007

Hi everyone!

This is my first post and I sure hope someone can help me. I have a 1999 GMC Sierra extended cab 4.8 engine. I had a brake line let go near what I guess is the BPMV ? it's the block where all the lines go for the ABS. Hear is where it gets bad I found the line I needed to change had to unscrew all the lines to get to the one that was broke I labeled all lines so I would know where they went and as I moved the broken line away three of the lines all broke up on the frame and now I can't tell what line goes where I have called all local dealers and everyone I know that works on trucks and nothing. The only thing I know for sure is that the line going to the back brakes is right now where do the other four lines go. Any help would be appreciated because even if I had another truck to look at the line are so screwed up you cant follow them back to the front of the truck to see what is what.

Thank you.

Macky

jnjspdshop · September 6, 2008

I am in the same boat with a customers 2000 Tahoe. Did you ever find a diagram or figure out which line goes where. I have check Alldata, Michell on Demand, and the GM dealer and no one seems to know

jnjspdshop · September 7, 2008

Well here is a diagram for everyone in the future that is looking for help on brake line porting routinghttp://jandjspeedshop.com/images/KelseyHayesBPMV.gif

dietz4ibanez · September 7, 2008

Is that from your work?

muddrum · October 13, 2008

Well here is a diagram for everyone in the future that is looking for help on brake line porting routinghttp://jandjspeedshop.com/images/KelseyHayesBPMV.gif

Thanks, just started to replace these same lines. Seems to be a common problem with these brake lines rusting out. Now if I can figure out how these plastic clips that support the brake lines come apart.

Edited October 13, 2008 by muddrum

KL Mallender · April 30, 2010

Hello all, just wanted to say Thank you for hosting this thread and replies along with the pictures, my nephew is elbow deep into replacing his rusted brake lines and lost track of proper line routing, I'm helping him finish what he started, he's learning the "It's not as easy as you think" quote pretty well right now, again Thanks.

Kevin.

TRAILCHARGER · July 25, 2010

I just broke two of these plastic brake/fuel line clips. Anybody know the part numbers for the clips or where I can get replacements?

Thank you

dadrummerray · July 20, 2011

Thank you J&J For posting this!!!!

Quadrasteer · October 19, 2011

I know that it's an old thread but I just wanted to clear something up just in case others are using this as a reference, like I did. On the ABS pump the 2 lower line ports for the master cylinder are labeled front input for the left hole and rear input for the right hole. This is correct BUT on the master the front line goes to the rear brakes and the rear line goes to the front brakes. It gave me a small problem and I had to switch 2 tubes at the pump. Not fun. I ordered a set of SS lines from ClassicTube and they fit great except the 2 on the rear axle were wrong for a '02 SD with 4ws, they now have the patterns (my old ones). They fit great and for some reason it was harder to get the old ones out than install the new ones. I taped up the ends of the new lines and plugged the ABS pump so no dirt got in when I used the air gun to clean the area. Then I sprayed the new lines with silicone and slid them in. Gas tank has to be dropped some and the job is a lot easier with the L/ wheel liner removed. Make sure that you remember where the lines and all the hold downs go and good luck! Thanks for posting the diagram and the pict. of the lines, I needed them.

Debo511 · October 19, 2011

Another description: 2000 Tahoe is the same.

When looking at the brake pipe port face of the BPMV, the ports are assigned as follows:

• Upper Left—Left Front Output

• Upper Middle—Right Front Output

• Upper Right—Rear Output

• Lower Left—Master Cylinder Secondary/Front Input

• Lower Right—Master Cylinder Primary/Front Input

Edited October 19, 2011 by debo511

Quadrasteer · October 20, 2011

Another description: 2000 Tahoe is the same.

When looking at the brake pipe port face of the BPMV, the ports are assigned as follows:

• Upper Left—Left Front Output

• Upper Middle—Right Front Output

• Upper Right—Rear Output

• Lower Left—Master Cylinder Secondary/Front Input

• Lower Right—Master Cylinder Primary/Front Input

The lower right port is labeled in the diagram as REAR input...not front

The whole point of my post was to point out that the lower left port that says front input is really the rear master cylinder line and that the right lower port that says rear input is really the front line on the master. The mechanics lable those two ports as right master and left master, in that order.

hikerfisher73 · October 23, 2011

A brake line let loose on my '99 last weekend, so I ordered the same SS kit from Classic Tube. It arrived on Thursday (they are fast!) and today I was outside looking at how I was going to get started. It doesn't look like the front passenger line is going to go in easy. In fact, it looks like I'm going to have to remove the radiator shroud and a bunch of hoses and cables to get it in, unless I cut it and add a splice. Any tips?

Patrick

Quadrasteer · October 26, 2011

A brake line let loose on my '99 last weekend, so I ordered the same SS kit from Classic Tube. It arrived on Thursday (they are fast!) and today I was outside looking at how I was going to get started. It doesn't look like the front passenger line is going to go in easy. In fact, it looks like I'm going to have to remove the radiator shroud and a bunch of hoses and cables to get it in, unless I cut it and add a splice. Any tips?
Patrick

Patrick, I'm not sure if your '99 is the same as my '02 but the F/R line was not as bad as it looked to change. You need to disconnect it from the ABS pump (I plugged all the ports because I made a lot of dust cleaning stuff with an air gun) snap it out of the hold downs (you might have to open 1 or 2 of them above the chassis by the pump, others pop right out) I think there were 13 of them. Take the left wheel liner and the front skid plate out to make it easier and disconnect it from the brake line at the wheel. When you're sure that it's all clear of any hold downs, you can pull it out from the bottom front, I did it a little at a time from each side. The rad shroud did NOT have to be removed. Like all the lines, I put black tape on the ends of the new lines and sprayed a little silicone on them. The new line went in much easier than I thought, the right side is very easy and the left needs to be aimed in the right place before you push it back in. The hardest part for me was getting all the lines to be in their original spots in the hold downs before the pump. You have to remember if the line goes above or below other lines or wiring harnesses, if you mess up then the other lines might not fit in their proper places. I took all the lines out at one time and it was hard to remember exactly where they went. The other problem area was above the gas tank, I had to lower it some and squeeze my hand in to get it loose and out (the back), luckly the new line slid in easily all the way foward.

Debo511 · October 26, 2011

Another description: 2000 Tahoe is the same.

When looking at the brake pipe port face of the BPMV, the ports are assigned as follows:

• Upper Left—Left Front Output

• Upper Middle—Right Front Output

• Upper Right—Rear Output

• Lower Left—Master Cylinder Secondary/Front Input

• Lower Right—Master Cylinder Primary/Front Input

The lower right port is labeled in the diagram as REAR input...not front

The whole point of my post was to point out that the lower left port that says front input is really the rear master cylinder line and that the right lower port that says rear input is really the front line on the master. The mechanics lable those two ports as right master and left master, in that order.

Primary will be for the front brakes and is the front portion of the master cylinder. Secondary is is for the rear brakes and is at the rear of the master cylinder.

Edited October 26, 2011 by debo511

Quadrasteer · October 26, 2011

Another description: 2000 Tahoe is the same.

When looking at the brake pipe port face of the BPMV, the ports are assigned as follows:

• Upper Left—Left Front Output

• Upper Middle—Right Front Output

• Upper Right—Rear Output

• Lower Left—Master Cylinder Secondary/Front Input

• Lower Right—Master Cylinder Primary/Front Input

The lower right port is labeled in the diagram as REAR input...not front

The whole point of my post was to point out that the lower left port that says front input is really the rear master cylinder line and that the right lower port that says rear input is really the front line on the master. The mechanics lable those two ports as right master and left master, in that order.

Primary will be for the front brakes and is the front portion of the master cylinder. Secondary is is for the rear brakes and is at the rear of the master cylinder.

"• Lower Left—Master Cylinder Secondary/Front Input

• Lower Right—Master Cylinder Primary/Front Input"

Your info has both inputs as "front", also the words Primary and Secondary might also be confusing, you would normally think of Primary as being the front and Secondary a being the rear. I like the way that the mechanics at my dealer label the 2 lower ports, the left one is "right master" and the right one is "left master". Less confusing that way.........