Flaring brake lines-need advice

[madkaw]

I am installing all new brake lines in my car along with my wildwood set up from AZC. I bought a brake line kit off of ebay that had the proper ends for our cars, but I need to cut and flare some ends for my proportioning valve. I only have to make 2 ends, but I am having no luck. I am using the autozone(probably harbor frieght version) free tool and I can't seem to make a good looking flare. The instructions with the tool are vague at best.

The instructions say to chamfer the end after you cut the length, but it seems that my tubing cutter already does that. I imagine the chamfer is to allow the tool to seat squarely against the line so it squishes flat and square. Then you follow with the tool to make the 45 flare. The problem for me seems that the flare doesn't come out centered in the line , maybe because the it didn't get squished squarely on the first step. It also seems the instructions are vague about how much line sticks out of the tool clamping device before you get started. I would love to hear any advice on this if anyone wants to give some.

[blue72]

Double flare right? Okay, for anyone interested here are the steps:

 

1. Of course, cut the tube, and make it straight. Get rid of any burrs on the inside (I use a small circular file).

 

2. Put the tube you're working with in the correct sized hole on the flaring bar. Take the appropriate sized adapter and place it flat side down on the bar next to the end of the tube. The end of the tube should usually stick out to the first "step" in the adapter. Next, tighten the side nearest the tube first, then make sure the other end is really tight. The little teeth in the hole are what grip the tube and prevent it from slipping. Here are the tube end and adapter side by side, and me tightening the clamps on the bar with a screwdriver for leverage.

 

3. Place the stem of the adapter in the tube, and put the yoke assembly in the center of the adapter. Tighten that baby down until it squishes the end of the tube against the bar.

 

4. Remove the yoke and adapter. Put the yoke back on without the adapter, and tighten all the way down again making the tube end form a bell shape, a 45 degree flare. Don't go too crazy with the tightening or you might split your new flare.

 

Loosen up the yoke again. Ta-da! you've made an honest to goodness double flare. Now you can make all of your friends jealous.

I think the real trick is getting the wingnuts on the bar nice and tight. If not then the tube will slip. Old worn out flaring bars do the same thing.

[madkaw]

Basically I did the same thing as you. My biggest problem is getting the first adapter to sit square on the tube to get that an even squish. My brake tool instructions showed putting a chamfer on the end of the tube before using the adapter. I am assuming the chamfer is on the outside of the tube since the adapter is machined in an inverted 45 around the stem. The pipe cutter leaves a bit of an angle on the end but the adapter does not sit solidly on the end of the brake line. I have practiced about 30-40 times to make a good flare, but I am lucky to get 1 out of 25 that look symetrical. I might have to just take it down the road, I'm about done f---in with it.

[Dave]

With the double bar type with two wing nuts to tighten it the two bars must be made exactly parallel by hand before you tighten it. I do it by feel, there's a lot of slop. If these are not exactly parallel, when you attach the screw driven flaring tool it will cock to one side and the flare will be off-center. If the lines you bought are stainless steel the cutter will work harden it and it makes the job harder yet. A little WD 40 helps on the end of the tube.

 

You can see the off-center flare looking down the end of the tube.

[madkaw]

The instructions that came with the tool said to tighten the wing nut closest to the line first then tighten the other nut. Honestly, I don't know if I checked for them being parallel(exactly), this maybe where I am screwing up. Does your tool require a chamfer on the end of the cut? Is your adapter machined flat around the stem part, or does it have a taper? It is exceptionally hard to keep the adapter perfectly perpindicular to the line making the first flare. I was actually concerned that the stem part was not the exact diameter of the line-there seems to be too much slop which exacerbates the situation of keeping the press perpindicular. This really seems to be an art, now I know why other guys have posted of problems.

[blue72]

My instructions tell me to chamfer the end of the tube as well. I left it out because I haven't found it to be completely necessary. The piece of tubing I demonstrated with wasn't a completely square cut, and I passed over the end quickly with a wire wheel, nothing special at all.

 

If you look at the pictures for mine you can see that the adapter had a taper around the base off the stem, and that the stem doesn't fit snugly in the tube (very loose actually). The pointy end of the yoke helps center the adapter in the tube while you tighten it.

 

Oh, and like Dave mentioned, my instructions say a little brake fluid will help lubricate if need be.

[madkaw]

You can see the off-center flare looking down the end of the tube.

 

 

So are you saying that they do come out off centered sometimes?

[Dave]

So are you saying that they do come out off centered sometimes?

 

No, if everything is lined up and the tool works at it should the flare will be centered. My old flaring tool that that I used to use always needed to have both halves lined up and at times the brake line would slip into the tool as I did the first part of the double flair. Clamp the tool together with out the brake line and see if the 2 halves are tight, mine was bent and I filed both halves until they were straight. If you are still working with the loaner tool and don't want to take a file to it you can use a large C-clamp or bench vice to force both halves together. At first I could not get a flare that was centered or that would seal until I fixed the tool. To chamfer the inside I use a drill bit and just did it by hand, and hit the outside with a file. I have a Mastercool hydraulic flaring tool now, but honestly the old tool works as well but takes a little longer. Just be sure both halves are lined up, the bar halves mating surfaces are straight and the brake line is champfered in side and out and your flare will come out perfect. Even the cheap Harborfreight tool that everyone loves to hate works well if it is checked and fixed.

Is your adapter machined flat around the stem part, or does it have a taper? [/Quote]

It has a taper that works best if the ID of the tube has a chamfer. My adapter is a very loose fit also. I don't know if the better hand flaring tools have a better fitting adapter but the loose one does get the job done.

[madkaw]

What determines the amount of sealing surface area? It seems that the flares I made had less sealing area then the lines I bought .

 

So you chamfered both ID and OD -hmmmm

 

When I get back in town I will try all this advice before I throw in the towel-thanks

[JMortensen]

Chamfer should be the INSIDE of the tube as Dave says, not the outside.

[madkaw]

Thanks Jon,

the instructions just had an arrow pointing towards the top of the tube and said chamfer. You couldn't determine if the arrow was pointing to the inside or outside.

[Dave]

What determines the amount of sealing surface area? It seems that the flares I made had less sealing area then the lines I bought.

If the flares you are making have less sealing area then one of two things are happening. The tube is slipping in the tool as you begin the flare with the adapter or the tube is not pushed far enough through the tool. Does your adapter have the step in it? and are you setting the tube even with the step like the picture shows.

[madkaw]

Yes the adapter has a step and the instructions showed having the top of the tube even with the first step. It also said to press the adapter down and stop just before it reaches the clamp. Another words, don't screw it down until it bottoms on the clamp.

What would be considered enough sealing area?

The lines I bought had probably 30% more then what I could fabricate. Sorry no pics-I'm out of town.

[Dave]

. It also said to press the adapter down and stop just before it reaches the clamp. Another words, don't screw it down until it bottoms on the clamp.

 

Just looked at mine and it says "Using swivel force adapter down until it rests flat against the flaring bar" and the picture shows it resting on the flaring bar. You will get more sealing surface by going that extra fraction.

 

The directions on mine say to "chamfer the outside and deburr the inside with the reamer blade" The reamer blade on my cutter does a poor job, that is why I used the dill bit. Some even use a 45 degree counter sink.

 

Where are you putting your proportioning valve? I have to do one for my 240Z but have not decided quite where.

[madkaw]

Dave,

I will take some pics Sunday, but I put the proportioning valve and the hydraulic brake along the console on the passenger side like Dave shows on his AZC site. It's a PITA to plumb and took me a long time to run it thru the body, that is why I am concerned about getting these flares correct since i have the lines bent already. I probably dumped a cup full of brake fluid on my floor with my first attempt bleeding my brakes since my flares sucked so bad. Of course I didn't notice right away where the fluid was going:oops:

[Dave]

Dave,

I will take some pics Sunday, I put the proportioning valve and the hydraulic brake along the console on the passenger side. I probably dumped a cup full of brake fluid on my floor with my first attempt bleeding my brakes since my flares sucked so bad. Of course I didn't notice right away where the fluid was going:oops:

When you cut the lines and flared them did you use a SAE nut for 3/16" tube? The brass fittings in the propotioning valve and ebrake valve are not for metric flare nuts they are SAE. The 10mm X 1.0 nut that fits the rest of the Z's braking system will bind up before it bottoms out on the fitting. You might want to look at the seat in the brass fittings that are screwed in the 2 valves. They are soft and may be damaged from the crooked flares. The fitting is a 1/8" male pipe thread by 3/16" SAE inverted flair and should be stocked just about everywhere.

 

Is the tubing your working with steel or is it stainless steel and did it come with the Japanese 10mm X 1.0 nuts? Did you reuse the tee in the back that splits the brake line?

[madkaw]

Dave,

I bought the brake line kit from ebay and they had the proper metric fittings. The lines are copper with a coating, they are very mallable.

The fitting I am putting on are standard to the proportioning valve-3-8/24 I believe, according to the instructions on the valve.I connected the proportioning valve to the hyrdaulic brake valve with 1/8 pipe. I could of bought an adapter fitting to go from my metric to the standard, but I didn't have the right length line anyway, so if I'm going to cut, I might as well put on the right fitting.

I left the tee because Dave didn't specify to remove it.

[Dave]

Dave,

I bought the brake line kit from ebay and they had the proper metric fittings. The lines are copper with a coating, the fitting I am putting on are standard to the proportioning valve-3-8/24 I believe.

 

You have the easiest line there is to work with and all the fittings are correct. It is just a matter of getting the flaring tool to work. Are you still working with the Autozone loaner tool? It just may be too trashed to work well. If your doing the flares in the car try to clamp the tool halves together with a large C-clamp.

I left the tee because Dave (AZC) didn't specify to remove it.[/Quote]

I asked about the tee because I need to find another one and have not found one other than on eBay for $35 (Ouch) I had a extra one here but it seems to have vanished. The 10mm X 1.00 flare nut is not easy to find either.

[madkaw]

The tool was brand new-never loaned out before. I think I will take the line out to try the flare-I need to get it right.

I will have a few extra of the metric fittings if you need one.

[Dave]

I will have a few extra of the metric fittings if you need one.

Thanks for the offer, I got lucky with the last trip to True Value hardware, I found they have AGS brand brake line in different lengths and their 8" Japanese line was $.99 each, so I bought a bunch of them.