Hi guys. I was practicing my bubble flares today and they weren't coming out quite as well as I had imagined. I thought I cut the pipe even but when I flare it, there's a little extra material perpendicular to the pipe. The flare itself looks good. Should I just file this extra material off? I lined the pipe up with the template but it seems like there was too much material forced into the flare. The excess seems to be flattened out in between the flaring "bit" and the metal piece that holds the pipe. Any advice?

 

Is this for brake lines?

 

yup unfortunately. I did 2 practice ones so far and will probably do about 5 or 6 more before trying to do the real deal.

 

Before I learned the benefit of flare wrenches I messed up one of my lines. You are using a Double flare tool? I first used the basic flare tool and couldn't figure out why I kept leaking. Buddy of mine had the kit with the double flare tool and that was it.

 

yeah, I tried the flare wrench too. Whoever tightened this thing down previously must have been training for the world's strongest men tournament. I tried everything, flare wrenches, pipe wrenches, ect. It wouldn't budge so I had to saw it off. I was already replacing the master so it wasn't any big deal.

So you ended up getting things to not leak with a double flare tool? I was told that the bubble flare works slightly better with the gm fitting. I got a replacement fitting at the dealer.

 

I hope he means he started with a double flare tool and then decided
to use the proper bubble flare tool.

It will be interesting if he actually tried to use a single flare and then
switched to a double flare.

Slightly better with the GM fitting compared to which other fitting?
An SAE/inverted/double/Japanese style flare nut with the internal
chamfer like the one on the left?



.

 

Are you using an ISO bubble flare tool? I hope so.

http://www.etoolcart.com/browseprodu...-AST-7827.html

Some will tell you that you can use a double flare tool by only doing the first step of the flare process. This may or may not work. I have both type flare tools, and the bubble flare is quite a bit different than the single step double flare.

Also, it is VERY important that your brake line cut is level and 90* w/r/t the straight line part of the brake line. After I cut the brake line, I used a flat file and small straight edge to ensure the flare tool would engage the brake line hole evenly. With that said, even if your bubble flare is a little off, the compression fitting will "mold" the soft steel bubble to the shape of the MC inlet when you tighten the flare nut. But do not Hulk Hogan the fitting, as your MC is aluminum. When I installed mine, I tightened my flare nuts snuggly, waited a few days, then noticed a very slight amount of brake fluid just below the fitting. I tightened the flare nut a little more, and no more leaks after that.

 

I first used a flare tool and of course it didn't work. Then used friends double fare tool and has never leaked again. I didn't use the bubble flare tool as you guys are saying to use. I guess in the future if I ever have a leak I will redo it with the bubble flare. Till then.....

 

Look closely at the pic. Double flare and bubble flare seal on different parts of the tubing.

Double flare is basically a fancy version of the single flare. Bubble flare is completely different. Double flare just happens to be smooth enough to seal ok and work in place of a bubble flare, although it still shouldn't.

You'd have to look at the other side that it attaches to to see what I mean.

 

it's good to hear the discussion and find out that I'm not alone out there in doing brake repairs. I'm a little intimidated after my first two flares, but I think that additional prep in making sure the cut is square will help. Thanks for all the advice everyone.

 

I think I gave you this link before, but can't remember....here's a pic of the bubble flare I made on my '93 brake line...

http://forums.corvetteforum.com/show...ghlight=bubble

 

thanks for the help guys. My bubble flares are looking better but now I have another issue. There isn't enough room with the fitting on the line to flare the line. There is a 90* bend where the line comes up through the engine compartment and then about 3" of line where the fitting goes on and where the flare is. With the flare on the line, and the tool on the line, there is maybe about 75% of the tube exposed that is required to make the flare. I need about 1/8" more material to make the flare. I guess I'm dead in the water. Any suggestions?

BTW, I'm using the cheap $25 tool that everyone else is using. Do the higher dollar tools require less line? Am I going to have to replace the line completely and if so, how much work is that going to be? I can't seem to locate where the line ends or where there is a break in the line. I assume that it's all the way in the back of the car where the abs box is.

 

Yes, to your assumption about the brake line. It goes all the way to the rearward ABS unit. Replacing this entire line would probably be a MAJOR PITA. I did the same thing as you, trying to trace the brake line from the MC back in hopes that there was a break in it. Not to be. I even got a brake line diagram from a local GM parts house for verification. If I can find it, I will scan and post. Bottom line though, this is one continuos steel line from the MC to ABS box.

These lines are soft steel, and I would think that there is some kind of straightening tool to get rid of the 90* bend so you could do your flare, and then rebend it back to 90* once you've completed your flare. That is why I was real careful to cut off just the head of the old bubble, 'cuz I knew the tool required some bit of straight length, and I would only get one shot at it.

I would not think that bending the line twice(once to remove 90* bend, and the other to reform it) would comprimise the integrity of the steel.

I would suggest that you start a new thread and inquire about brake line bending tools.

Another, riskier option, would be to try to get a half way decent flare with the 75% line that you do have to work with. Try this out with some spare brake line and what you get?????? It may be enough to curl the end of the brake line to give you a working bubble flare.

 

Hey, I guess I was really bored, so I tried making a bubble flare with about 1/8" of missing brake line coming out of the clamp. I got excellent results and I even had an extra fitting lying around to see if it would seat properly...No problems. I think with 75% of required straight line coming out of your clamp, you will be fine. Here is a picture I just took of the bubble flare I got with approximately 75% line for flare. Make sure you sand the straight line where the clamp goes. This aids in keeping the brake line from slipping through as you tighten the 4.75mm flare adapter. Also, use a pair of pliers to tighten the 2 large wingnuts on the brake line clamp, You want this as tight as possible.

I say go for it !!

 

thanks mike. I'll give it a go

 

Holy crap Mike!!!!! I flared that sucker and it was by far the best looking flare of my life. I did about 6 practice flares earlier today and none of them look nearly as good as this one. Hopefully this works out! Thanks for the help!!!!!!

 

Awesome ! I bet you have no problems with leakage from this fitting....

Also, is your MC mounted to brake booster? If yes, loosen it so that when you thread the fittings, you don't cross thread them. I found it was easier to get the brake nuts threaded while I was holding the unmounted MC in my other hand. This gives you room to angle the MC instead of trying to bend the brake line. Be VERY carful, as these are easy to cross thread if you are not careful(fine ptch threads make it hard to visually verify that the nut is going on straight). Finger tighten until you are able to make about 4 or 5 revolutions of the fitting into the MC....

 

Well, I got it back together. I'm calling it a day and tommorrow I'll bleed the system and see if there are any leaks. My fingers are crossed.

thanks again to all that helped.