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Brake Hardline Advice


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Need some input here.

My car is a 7/72 build but still has the early braking layout.



So the left rear brake line is clogged.  Nothing comes out the bleeder screw.  I disconnected the rubber line from the hardline on the hub, still nothing.  I disconnected #15 from #18 above, and brake fluid came out.

I'm pretty handy with a wrench, and was using the right tools (10mm and 19mm flare nut wrenches + PB Blaster), but 49 years of never being disconnected must've taken its toll, and neither hardline would separate from the rubber lines near the brake drums.  Nuts rounded completely.

So I had to cut the hardlines next to the nuts (sorry for the terrible pic; I took it in the garage afterward):


Question:  Should I try to source replacement lines, or just buy parts and tools and bend new lines myself?  I have new rubber lines ready to go; just need to get the hardlines sorted.  Am I correct in assuming the lines are 3/16" with inverted flare 10mm x 1.0 fittings?  And I can buy a brake tubing bender and flare tool?

Thanks for any and all input.

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I'd say you'd be better off making them yourself as it's not too hard if you've got the right tools and some old lines to copy, which you do. You'll save some money doing it yourself, too. From my understanding, there are prefabricated kits though if you wanted to go that route. Also the lines are 3/16 with 10x1.00 fittings, but it's a double flare - I don't know if inverted flare and double flare are the same. You can get a flaring and bending tool at your local autoparts store, but get good tools as they'll make your job a lot easier. For a flaring tool, I highly highly recommend this: https://www.summitracing.com/parts/ttn-51535 I used one of those generic kits when I first did some brakelines and wound up making a bunch of crumby flares after hours of cussing and frustration. Got that tool and made perfect flares in no time, every time. Plus, you can flare lines while under the car if something goes awry! For the price, it's far and away the best tool you'll find. But don't just take my word for it: https://www.classiczcars.com/forums/topic/65362-brakeline-question/?&page=2#comments I got mine at an O' Reilly I think, but you could get it online if nothing else. 


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It depends on how much time and enthusiasm you have!

I bought all the bits and did my own in lockdown. I did every single line except for one and it cost me less than £100 including tools.

Copper (which is what was on the car) is an absolute no no as it “work hardens” and goes brittle / cracks over time. I believe it’s illegal to use on brake lines in many countries for that reason.

You can use stainless steel tubing which is really tough to bend but I went with cupronickel which is also tough to bend but easier and doesn’t have the above issues..

There are cheaper flaring tools but the one below gives the cleanest finish / flares.

AB Tools Brake Pipe Flaring Tool Professional In-situ 3/16" SAE Hand Held FL29 https://www.amazon.co.uk/dp/B01M4RC2YW/ref=cm_sw_r_cp_api_glt_fabc_1BN1QE78QNG5KNVBV53S?_encoding=UTF8&psc=1

Sealey CNP316 Brake Pipe Seamless Tube Cupro-Nickel 22 Gauge 3/16" x 25ft BS EN 12449 CW024A https://www.amazon.co.uk/dp/B01H0966GK/ref=cm_sw_r_cp_api_glt_fabc_0DVE4HSMJB88JKBNNCFZ?_encoding=UTF8&psc=1

Pearl PBU437 M10 Male Brake Pipe Union PP54 (50 Pieces) https://www.amazon.co.uk/dp/B006HFM5FK/ref=cm_sw_r_cp_api_glt_fabc_NQT8ZYZ3ZNMYFPK3GA5Z?_encoding=UTF8&psc=1

Pipe bender

Amazon prices are higher than other places but it gives you a sense of what you need.

I used the pipe bender and various sockets / tins of paint to get the radii I needed.

This is a very satisfying job to do.

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That hand flaring tool that Tweed linked to at summit is the best hand tool I’ve used. Works fantastic.

Use the copper nickel tubing you can bend 90% with your hands. I love buying it and nuts from thestopshop though amazon. 

Tubing prep is the secret. Internal deburr and external chamfering.  This https://www.eastwood.com/eastwood-tubing-deburring-tool.html?gclid=Cj0KCQjw-NaJBhDsARIsAAja6dMfxmxKJNlKjBV_RuyxduUX2yo3UbNMKMbgMFcZvW-Ir7V7sHT7Y_gaAjtFEALw_wcB&wickedid=345665394423&wickedsource=google&wv=3.1 

Works very well.

And blow the chips out of the tube before you use it!




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And then I found this!


Might be worth the money. $300 bucks. It’s the early set too.

And I’m loving what these guys are doing with reproduction body parts! Check them out!

Edited by zKars
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Thank you all for the GREAT input.  I think I'm going to try to tackle this myself.  I really appreciate the links to the tools in particular.

Re:the link to the full set for $300, I'd seen that (those guys are somewhat local to me and I follow them on Twitter), but I really don't have any inclination to re-run the whole braking system at this point.  Maybe 1.5 years ago when the engine and trans were out and I didn't have to work around them...

Will report back once I have some supplies.

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  • 7 months later...

Reporting back here.  Winter got caught up in some home improvement projects (our pantry looks fantastic now), but I'm back on the Z kick.

All the tools and supplies came:


And I practiced a bit before attempting to fabricate lines for the car:


I think they came out OK:


All new rubber lines as well, no leaks and we're back in business.

Still might buy the later S30 conversion kit, though, since early Z brake cylinders are NLA.


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I’m all for DIY but the Classic Tubes kit is quick and accurate. @Yarb says to avoid the stainless steel set as he had a lot of trouble with bleeding and leaks? I don’t think it’s a bad idea to avoid putting bling in places you can’t see. 

Just putting this out there for those who don’t want to buy tools and put effort in to building lines.

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