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Mod | | | Forums66 Topics128,113 Posts1,056,279 Members48,439 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Feb 2006 Posts: 1,867 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 1,867 | Im finally getting the rear hubs all put back together on the COE and I started looking at flaring the brake lines between the wheel cylinders. Mind you, this setup has two wheel cylinders per side and has a 10" line that goes between them.
But instead of a standard 1/4" inverted flare nut which has 7/16-24 tpi, this has a 7/16-20 tpi, just like the banjo bolts. Where in the heck can I get new flare nuts that have this thread???
Thanks, Jeff | | | | | Joined: Mar 2007 Posts: 863 Shop Shark | | Shop Shark Joined: Mar 2007 Posts: 863 | | | | | | Joined: Jul 2007 Posts: 461 Shop Shark | | Shop Shark Joined: Jul 2007 Posts: 461 | The steel lines would have double flares. The nuts for double flaring might have different threads as well as a different angle. I've always used steel nuts for double flares on brake lines, and haven't compared single-flare hardware with double-flare types. I'm sure someone else can fill in some details on this.
Harvester | | | | | Joined: Feb 2006 Posts: 1,867 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 1,867 | | | | | | Joined: Feb 2006 Posts: 1,867 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 1,867 | I may have found a good replacement thanks to Tim at Fedhill Brakes He said the british flare fitting for 1/4" lines has the 7/16-20 pattern but he wasnt sure that it would thread deep enough to seat properly, or that the unthreaded portion at the tip would interfere. Thanks to Tims info, I think Ive found them locally and Ill know for sure come wednesday when my daily adventures take me by their shop. So until then Im still open to any ideas, and Ill make sure to post whether or not they work. Thanks, Jeff | | | | | Joined: Jul 2004 Posts: 2,987 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 2,987 | | | | | | Joined: Jan 2002 Posts: 59 Wrench Fetcher | | Wrench Fetcher Joined: Jan 2002 Posts: 59 | I had the same problem on my 64 C60. The line was rusted to the nuts and broke when loosened. I soaked the nuts in liquid wrench, stuck them in a vise drove out the broken line with a brass rod. Then put the nuts on a new piece of brake line double flared and bent it to shape. Not the easiest job but it worked great | | | | | Joined: Feb 2006 Posts: 1,867 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 1,867 | I stopped in at the hydraulic shop that usually carries everything you cant find elsewhere. They were able to scrounge up a few 1/4" flare nuts with the 7/16-20 tpi. Its a good thing I asked about the unthreaded end portion as several had no taper at all which had the owner scratching his head.
Now that Im home, Ive slipped them on a flared tube and they look like they will work out great. Its gonna be tight on room though as they are about 1/4" longer then the originals. Ill get some pics when Im all done.
Jeff | | | | | Joined: Sep 2006 Posts: 1,997 Big Bolt Forum Co-moderator | | Big Bolt Forum Co-moderator Joined: Sep 2006 Posts: 1,997 | Rusted nuts, check out the page below, I am wondering if those adapters are for using with the 7/16- 24 nuts. http://www.fmsiinc.com/brake-line-fittings.htm A day without laughter is a day wasted- Charlie Chaplin When wrestling a grizzly bear, you have to keep at it until the bear gets tired, not when you get tired. 1948 Chevy 2-Ton | | | | | Joined: Dec 2003 Posts: 1,144 'Bolter | | 'Bolter Joined: Dec 2003 Posts: 1,144 | ok on my 38 1.5 am i going to need these 7/16-20 flare nuts instead of standard. when I did it before i screwed them in but some didn't fit very well. will these be needed at all conections or just at the rear. | | | | | Joined: Feb 2006 Posts: 1,867 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 1,867 | Im not sure how the braking system is on a 38...
These tube nuts only go between two wheel cylinders on each side of the truck, only on later models. Typically the brake lines connect to a brass block that has a hole through it where a banjo bolt (hollow bolt) slides through and connects to the wheel cylinder. There are also copper washers that are on either side of the brass block and give a crush seal to the banjo bolt and wheel cylinder.
Does that sound right???
Jeff | | | | | Joined: Dec 2003 Posts: 1,144 'Bolter | | 'Bolter Joined: Dec 2003 Posts: 1,144 | Thanks the 38 only has one wheel cylinder per wheel on the rear it does have the banjo bolts,brass blocks and crush washers. I got away with half way doing things before and am trying to get things back together a bit more safely this time. I didn't have any lines leaking back then but some didn't thread in very far and seeing your post it caught my attention. | | |
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