How much brake line is needed to replace all the hard lines?

[Cyrix2k]

Story time: I was tuning the e30 today after the car's been sitting for about 18 months. I've put maybe 30 miles on the in last month or so and it seems to have been stopping fine - until today. I was doing an easy pull into boost while in 3rd, then went to stop hard to catch a small road for a U turn. Well, the car was stopping then the pedal dropped and the car was no longer stopping. I was just down the street from my house and the road was clear, so I was able to slow down enough to pull into someone's driveway just by downshifting and using the handbrake. It was still VERY scary, but luckily most of the speed was bled off by the hydraulic brakes and the handbrake works pretty well in this car. I drove the car down the street back to my house in a low gear and it wasn't a problem. Initially, I thought the problem was the master cylinder, but the reservoir was low & there was brake fluid coming out by the rear passenger side wheel. Uh oh. During the course of the motor swap I noted the brake lines by the driver's side wheel well looked pretty nasty, but I never looked at the rear. There was only a section that looked bad up front so I thought the other portions were fine - NOPE. So does anyone know how much tubing is needed to redo the whole brake system? How about just the rear brakes, including the feed line to the T from the master cylinder? This is a non-ABS car.

[jlevie]

The best thing to do is to get replacement lines from BMW. They'll come with the end fittings in place and all you need do is to bend them to match the originals.

[Cyrix2k]

The best thing to do is to get replacement lines from BMW. They'll come with the end fittings in place and all you need do is to bend them to match the originals.

I'd do that, except their tubing is more expensive than rolled tubing and harder to form than the Cunifer tubing which never rusts. I did some digging in the ETK and found this:

In millimeters
Rear
------
From master to pressure regulator - 360
(from Pressure Regulator) Main - 3120
Branch from Tee- 380
Branch from Tee- 283
Trailing Arm - 751
Trailing Arm- 751

Total Rear - 5645

Front
-------
Passenger - 1612
Driver - 360

Total Front - 1972

Grand Total - 7617

That puts the grand total at 24.9901575 feet (24 feet 11⅞ inches) according to google. The roll of tubing I ordered is 25 feet long, but the other lines on the car look ok. I think that will give me what I need to replace any rotted lines.

[jlevie]

I'm guessing that you have a bubble flare tool?

[Cyrix2k]

I bought this one

http://www.amazon.com/OTC-4504-Stinger-Bubble-Flaring/dp/B0015PMZMU/ref=sr_1_fkmr0_1?ie=UTF8&qid=1340217323&sr=8-1-fkmr0&keywords=OTC+stringer+bubble+flare

The prices on the BMW line are a good deal higher than what's listed in the ETK, so I was able to get the rolled line, tools, and the flare nuts for less than the buying line from BMW - and I would need a tubing bender to work with their line.

[yyi]

The best thing to do is to get replacement lines from BMW. They'll come with the end fittings in place and all you need do is to bend them to match the originals.

By getting them from BMW you mean #9-14 as shown in this diagram right?

http://www.realoem.com/bmw/showparts...53&hg=34&fg=15

[Cyrix2k]

Yes, but that's for the rear only. I pulled my lengths from the description. BTW, my tools & new cunifer line came in today. I'm glad I went this route over the BMW line; the cunifer is easy to work with, looks great, and will never rust. Once and done!!!

[yyi]

Congrats! glad it worked out for you.

I have a question about the fittings though. I understand you would have to flare the ends if you are not going with the oem lines. But what about the threaded fittings? Do you have to reuse old ones? If not, where and which did you get?

[Cyrix2k]

Congrats! glad it worked out for you.

I have a question about the fittings though. I understand you would have to flare the ends if you are not going with the oem lines. But what about the threaded fittings? Do you have to reuse old ones? If not, where and which did you get?

You can reuse them if they're in decent shape or buy new ones. I bought these

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dtools&field-keywords=SRRBR250

Still waiting on them :-/ It's the only thing I still need.

[yyi]

Cool, I've been wondering about the pitch and dia of the brake fittings, good to know. Also, did you get 3/16th lines? I've found some very unfortunate developments in my lines, so I may be taking the same route as you are very soon.

Keep us updated on the progress and how everything is coming together!

[Cyrix2k]

Cool, I've been wondering about the pitch and dia of the brake fittings, good to know. Also, did you get 3/16th lines? I've found some very unfortunate developments in my lines, so I may be taking the same route as you are very soon.

Keep us updated on the progress and how everything is coming together!

yes, I did. 3/16" and 4.75mm are considered interchangeable. I'll post an update when it's all done!

[Cyrix2k]

OMFG this is the job from hell. My lines, including the rubber lines, are original and rusted together. I have quality line wrenches and crows foot line wrenches and CANNOT get these lines apart without destroying them. This ordinarily wouldn't be a problem, but I was hoping to reuse the hard lines on the trailing arm, the rubber line if it wasn't old, and there are brackets between the rubber lines & hard lines that need to be saved - I'm getting ready to check if they're bolted or welded to the body. Anyway, access is terrible but manageable if the lines aren't rusted solid. Arghhhh. The aforementioned brackets are impossible to get to with the subframe in the car so if these don't come loose, the lines either need to be rerouted with new brackets put in OR the subframe needs to come out.

[Cyrix2k]

Update: I have brakes!!!! I replaced both rear lines but not the main feed line... I'll get to that, but it's in a good deal better shape than the two I replaced. Oh, and I left the rear seat intact. Running the new line was 10000000x easier than pulling the old line. It's actually fun :)

Tools. Note that nowhere near that much brake fluid is needed.

Is there any wonder I had problems?

A shot of one of the new lines. That cunifer tubing is AMAZING to work with. It bends easily by hand without kinking and also flares well. The fittings I ordered also fit perfectly although the spring clips for the soft lines are a bit loose. No biggy.

[yyi]

HA! My T-fitting looks EXACTLY the same, I almost feel like I have to redo the line all the way to the front.

Looking good, keep us updated with the progress!!

edit: Did you also get the brake lines from the same amazon vendor that you bought the bubble flare nut from?

[Cyrix2k]

They're made by the same company, SUR&R, but I bought them from different vendors as it was cheaper. I've been driving the car around without trouble. I'll replace the line going that goes from the front to the rear tee when it cools down.