I posted this on bimmerforums and figured I might as well post it here. Updates will be in the BF post.
Hi, this is the third time I have done this on my cars. Well, two cars were done this way, and one was slightly different. This can be done on the ground on ramps (I have done it) but it is far easier to do this on a lift. Nobody wants to remove the subframe to repair the rear brake lines that go above the diff and subframe, and part of the gas tank. It probably cost about $50 in parts/fluid and took me about three hours with the car on the lift today. The hardest part is loosening the rear brake line from the proportioning valve below the brake booster, and the second hardest part is connecting the new line to the proportioning valve. But hey, atleast we DO NOT need to remove the subframe!
I left most of the old stuff in the car. I think I only removed the main rear line from the proportioning valve back to the tee junction. The brake tee junction was rusted and I couldn't remove the bolt but it really doesnt need to come out. Plus you can zip-tie the new brake tee junction part of the old main line going to the old tee junction. I also left the old inner lines and hoses in the car.
Parts I used:
About 7' of 1/4" nickle copper brake line because it is super easy to bend by hand and that makes it very easy to route around the gas tank.
One Inner rear brake hose 34321159878
One Outer rear brake hose 34321159881
One brake tee junction 34341111435 It is M10X1.0 used in VW, Audi, and some Japanese vehichles
8" brake line (I used AGS BLJ308)
I had the line and the junction, so I bought the soft hoses from Carquest. They can usually get stuff the next day if they don't have it on the shelf.
Carquest BRK SP8639
Carquest BRK SP6247
Also it is a good idea to have a couple spare bubble flare nuts just in case the originals can't be used. I had to reuse the rear one since I left it on the original junction tee.
This is what I used:
Luckily there is a case of these things.
Before doing this, I would sugggest making sure you can separate the old inner soft hoses from the old outer hard lines and nothing breaks. I reused the old hard lines (the ones on the trailing arms). And I would make sure you can get the old main line off the bottom of the proportioning valve (super hidden under the brake booster). I had to use vice-grips on this so it didnt move when I removed the flare nut of the old main line.
Here is what we are making:
Honestly, It is easier to put this together on the bench so you can tighten it up without anything in your way.
Once you make that, you can slide the passenger side line above the rear diff and put it in the bracket. You will need to bend the line slightly so it doesnt rub on the diff or subframe.
And here is the driver's side almost finished:
Now, I forgot to continue taking pictures while I completed this. So here is a picture of the last E30 I did:
The car is still on the lift so I will take pictures tomorrow to show the rest.
The routing of the main line is pretty straight forward. I started from the back and worked forward and zip tied the tee junction and line to something solid(ish). It just made sense to do it that way because I was working with a new 100' spool of this copper line and I didnt want to cut the wrong amount. Just take your time and have fun. You will have tons of fun getting this line connected to the proportioning valve below the brake booster. It probably took me half an hour. I thought I had it threading in but then I realized it was crooked. It is very hard to see and visibility is zero when your huge hand is in the way.
Hi, this is the third time I have done this on my cars. Well, two cars were done this way, and one was slightly different. This can be done on the ground on ramps (I have done it) but it is far easier to do this on a lift. Nobody wants to remove the subframe to repair the rear brake lines that go above the diff and subframe, and part of the gas tank. It probably cost about $50 in parts/fluid and took me about three hours with the car on the lift today. The hardest part is loosening the rear brake line from the proportioning valve below the brake booster, and the second hardest part is connecting the new line to the proportioning valve. But hey, atleast we DO NOT need to remove the subframe!
I left most of the old stuff in the car. I think I only removed the main rear line from the proportioning valve back to the tee junction. The brake tee junction was rusted and I couldn't remove the bolt but it really doesnt need to come out. Plus you can zip-tie the new brake tee junction part of the old main line going to the old tee junction. I also left the old inner lines and hoses in the car.
Parts I used:
About 7' of 1/4" nickle copper brake line because it is super easy to bend by hand and that makes it very easy to route around the gas tank.
One Inner rear brake hose 34321159878
One Outer rear brake hose 34321159881
One brake tee junction 34341111435 It is M10X1.0 used in VW, Audi, and some Japanese vehichles
8" brake line (I used AGS BLJ308)
I had the line and the junction, so I bought the soft hoses from Carquest. They can usually get stuff the next day if they don't have it on the shelf.
Carquest BRK SP8639
Carquest BRK SP6247
Also it is a good idea to have a couple spare bubble flare nuts just in case the originals can't be used. I had to reuse the rear one since I left it on the original junction tee.
This is what I used:
Luckily there is a case of these things.
Before doing this, I would sugggest making sure you can separate the old inner soft hoses from the old outer hard lines and nothing breaks. I reused the old hard lines (the ones on the trailing arms). And I would make sure you can get the old main line off the bottom of the proportioning valve (super hidden under the brake booster). I had to use vice-grips on this so it didnt move when I removed the flare nut of the old main line.
Here is what we are making:
Honestly, It is easier to put this together on the bench so you can tighten it up without anything in your way.
Once you make that, you can slide the passenger side line above the rear diff and put it in the bracket. You will need to bend the line slightly so it doesnt rub on the diff or subframe.
And here is the driver's side almost finished:
Now, I forgot to continue taking pictures while I completed this. So here is a picture of the last E30 I did:
The car is still on the lift so I will take pictures tomorrow to show the rest.
The routing of the main line is pretty straight forward. I started from the back and worked forward and zip tied the tee junction and line to something solid(ish). It just made sense to do it that way because I was working with a new 100' spool of this copper line and I didnt want to cut the wrong amount. Just take your time and have fun. You will have tons of fun getting this line connected to the proportioning valve below the brake booster. It probably took me half an hour. I thought I had it threading in but then I realized it was crooked. It is very hard to see and visibility is zero when your huge hand is in the way.
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