E30 Rear Brake lines and T junction replacement without removing subframe DIY

[15Michaeljoseph]

Just to update, progress has been delayed due to crazy work schedule. Continuing application of pb blaster, and I bought a set of flare wrenches.
Do you think using copper nickel line for the section over the diff is a bad move? I wasn't sure if it'll flex and bend and over time end up breaking... Maybe I need to get the steel like you did?

--Mike

[barbierij]

I'm sure it's fine. I used it on two of my cars and I just zip tied it to something that didnt move. For extra protection, you can put some fuel line over the line to dampen vibrations where you have it zip tied. I was lucky enough that some of the original plastic mounts from the old line were usable.

[15Michaeljoseph]

Awesome. I'll go ahead and use that 8in copper. Nice idea with the fuel line too... I'll be sure to take pictures, hope to be tackling on Friday.

--Mike

[barbierij]

Good luck dude!

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[audiquattrot]

I remember having to do this on my first E30. Dropping that rear subframe was a b*tch just to get to this section

[15Michaeljoseph]

Alright. So I began the project today. I have been hitting the flare nuts with PB blaster on and off for about 2 weeks or so. Today I get under there with my 11mm flare wrench, and my backup for the soft line, to undo the trailing arm line on the passenger side. Even using the 11mm (10 was too small, 12 was too big) it rounded off. Now mind you, it didn't even look that rusty. Visegrips... Still no luck. And the nut is starting to look rhubarb. So I guess I'm going to just go ahead and measure what kind of line I'll need for the trailing arms. Grrrrr. Be back in the garage tomorrow.

--Mike

[barbierij]

Bummer that sucks. You can probably get away with making the control arm lines with the steel stuff by bending it around a Billy Buckner bat to match the old lines. Cut the old ones out flush to the fittings and add an inch to the new line on both ends.

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[15Michaeljoseph]

Got the new copper line for the trailing arm installed yesterday. Today, I installed the new rubber hoses to the calipers, and got that T fitting creation molded over the diff, with the two rubber lines attached to the fresh copper on the trailing arms. I ziptied the new T very close to the old one, and put a slice of rubber fuel line around the piece of old line I couldn't get out, so it doesn't make noise or anything. Ran my copper up front to the union under the door, going to flare that tomorrow and see what kind of shape its in. Have to secure that new copper section as well. My flares look okay for a novice using a rental tool. I just have to learn to be more patient. Here are the pics of the passenger trailing arm set up (I will take more pictures of all the work I did tomorrow first thing, while my hands are CLEAN.)


I'm excited to get it working and see how it feels. Hope my flares are good :'). Bleeding won't be too bad, I've got plenty of new DOT 4...

--Mike

[barbierij]

very good job!

[15Michaeljoseph]

Lunch break update.... tucked behind fuel filter in stock location.... Aaaannnnd.....

Connected to the not-so-old repair line.

Had mama come out and press the brake pedal for me to bleed... That joint in the final picture was leaking, but I tightened it up even more, and it stopped... It was fair flare, not perfect, but not bad or crooked, so I figured I'd have to tighten it up more.

So. Now I jut have to get the lines secured up to the car, put the cat back back on, get the wheels on, and bleed the fronts.



Oh and by the way


These are the soft lines I pulled from the car. The intact ones are from the rear calipers, the cut ones are from the diff area. They look okay, but they're all original, reading November and December of 1986 production dates... Whew. I kind of wish I bought the front soft lines now though... That way I wouldn't have to do even more bleeding at a later date. Oh well. High blood pressure can't always be a bad thing.



--Mike

[15Michaeljoseph]

So the brakes were bled, and I have been driving her each day. All I can say is wow. The old rusty brake lines were really the last 'necessary' repair that was detracting from my driving experience. The pedal is more firm then it was before, though not rock solid, but everything feels and looks good. Ideally, I'll be replacing the front soft hoses soon, and re-bleeding the system once more, not to mention the fact that I'll be installing new rotors and pads on all four corners when this set of pads are done, further improving the stopping power. This excites me.

Thank you, barbierij for the ingenuity and thorough DIY, with a (beginning) parts list and nice pictures for us 'visual learners'.
I hate to sound crazy or dramatic, but I am so much more confident in the car now, and I enjoy driving it so much more now. Plus, it's one less thing to worry about.

I highly recommend this 'mod-repair' for anyone who has questionable brake lines, and cannot or will not drop their subframe for one reason or another.

--Mike

[barbierij]

You're welcome! I'm glad it worked and you have that E30 braking power again!

[Coupenut]

Great post, this was a big help in replacing the lines on my iX. The only place that I deviated was at the front of the car disconnecting the hard line from the proportioning valve. Too much contorting and very limited visibility, so I pulled the MC and booster. Probably took less time and was far easier than trying to work around them.

[barbierij]

Great post, this was a big help in replacing the lines on my iX. The only place that I deviated was at the front of the car disconnecting the hard line from the proportioning valve. Too much contorting and very limited visibility, so I pulled the MC and booster. Probably took less time and was far easier than trying to work around them.

I'm glad it helped you! I might take your advice if I have to do this again.

[Grackle]

So do you guys do this just to replace the rubber lines above the diff? I got a full set of braided lines. I was able to easily change the front and rear caliper hoses, but I can't figure out how to get to the top metal lines. Fortunately mine have all easily come apart due to the car being in Texas it's entire life.