Double flaring help?

[panchovilla]

I have a 85' minitruck and I am trying to put a linelock and manual proportioning valve into my rear brakes. The rerouted brakelines ended up far to long, hence I cut them off at the appropriate lengths and had to reflare the ends. Also, the factory toyota brakeline threaded ends have a short section of no threads at the base of the end. This does not allow me to use them in the "universal" linelock for 3/16" brakelines, whereas a new end has threads all the way down to the base of the end. So after putting new ends that I bought at Napa, and doubleflaring the newly cut ends, my brakes leak tremendously at the linelock.
So I guess what I am looking for help with is:1)Is a stock toyota brakeline 3/16"?,2)I followed the directions to the double flaring tool that I bought at Napa to a T, is there some trick to flaring that I am not privy to?, 3)Or should I bite the bullet and buy new brakelines?

 

[KLF]

Toyota lines are actually 4.75 mm, but that is extremely close to 3/16", that should work fine.

Getting a double flare on these lines can be very tricky, unless you splurge for a really expensive flaring tool. This is the one I have, it is probably very similar to yours:

Amazon.com: Advanced Tool Design ATD-5464 Bubble Flaring Tool Kit (ISO): Automotive@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41y3z4shiqL.@@AMEPARAM@@41y3z4shiqL

Here's some tips on how *I* do double-flares, learned after many failures:

* Don't use a tubing cutter to cut the tubing. I know this sounds odd, but I read somewhere that the cutting action of these cutters will harden the steel tubing right at the cut and make it much more difficult to get an even flare. What I use is a Dremel tool with a cutoff wheel. Don't worry about getting the cut perfectly perpendicular now, just cut it as square as you can.

* Then I chuck the tube into the clamp part of the flaring tool, with maybe 1/32" or so of the tube sticking out past the flat. Use a nice sharp mill file to file the end of the tube off, down to flat with the clamp. This will make sure the end of the tube is perfectly square.

* Remove the tube from the clamp, then use a small smooth file to put a very slight bevel on the end of the tube, just enough to remove any burrs. Use the tang of a small file to remove the burrs inside the tube as well.

* Put the tube back into the clamp, at the stickout required by the tool. Clamp it down REALLY tight, then put it in a vise.

* Flare as normal.

Give it a try.

 

[Chop Shop]

What does the flare look like? Was it nasty looking when it came out?

You should be able to see if its gonna leak before even putting it on.

 

[2ndGenToyotaFan]

Dont' forget to put the threaded part on first!!!!!

 

[pappy]

When I made the lines for my FJ40 I didn't have any problem using a tubing cutter. For the inside burr I used a counter-sink bit by hand. For the lines I used 3/16" lines and the original Toyota fittings. No problems, no leaks. I also used the inexpensive tool KLF shows. It's not a great tool, but does get the job done.

 

[panchovilla]

KLF,
Thanks for the tips, your ideas all make great sense, I will let you know how it goes this weekend. The kit that I bought is very similar to yours. I was a little anxious to get my brakes done, thinking it was going to be braindead easy with the kit, WRONG! This time I will take my time.

 

[Bogo]

If I don't have access to my shop or am feeling lazy, I just coil up the excess tube in some spot that is out of the way and won't get caught on something. This is also much faster than putting a new end on. Often I'll buy two lines plus end to end splice that are in total 8+ inches longer than needed. I plan the join between the two to be where I will loop the excess. There are also end to end clamp on joints that don't need flairs, but I wouldn't use them on anything but new tubing. Also I think they are technically illegal now.

My flairing tool is an old ****py rusty POS I grabbed from grandpa's farm when he retired and said come and grab what you want. It has never failed me. I do use a tube cutter, but I cut the tube about 1/8" long, and grind off the end. I stick a bit of balsa or wad of paper into the tube to keep the metal shavings out, then use and air compressor to blow it out when the grinding is done. I use a bench grinder and just eyeball it flat. Then I lightly debur with a deburing tool for the inside and the grinder for the outside. The rest is crimping like normal.

The comment about tube cutters is correct, they WILL work harden the cut edge, and depending on the cutter they may also work harden the tube where the rollers of the cutter run. Hence the grinding it off after cutting.

Here's some tips on how *I* do double-flares, learned after many failures:

* Don't use a tubing cutter to cut the tubing. I know this sounds odd, but I read somewhere that the cutting action of these cutters will harden the steel tubing right at the cut and make it much more difficult to get an even flare. What I use is a Dremel tool with a cutoff wheel. Don't worry about getting the cut perfectly perpendicular now, just cut it as square as you can.

* Then I chuck the tube into the clamp part of the flaring tool, with maybe 1/32" or so of the tube sticking out past the flat. Use a nice sharp mill file to file the end of the tube off, down to flat with the clamp. This will make sure the end of the tube is perfectly square.

* Remove the tube from the clamp, then use a small smooth file to put a very slight bevel on the end of the tube, just enough to remove any burrs. Use the tang of a small file to remove the burrs inside the tube as well.

* Put the tube back into the clamp, at the stickout required by the tool. Clamp it down REALLY tight, then put it in a vise.

* Flare as normal.

Give it a try.

 

[panchovilla]

The problem has been alleviated. I reflared the brakelines using the filing technique mentioned here somewhere, looked much better. The actual problem, I found out, was a stripped adapter at the linelock. Thanks for the help.
After finishing the brake upgrade on the '85 I can say that the single best thing that you can do for your brakes is upgrading to a FJ80 master cylinder with manual rear proportioning valve. This upgrade will make your brakes more powerful than ever. I highly recomend it.