Bubble Flareing on the brake lines.

[fun car guy]

Okay, You guys have likely gotten tired of me belly aching about getting a good bubble flare on my '89 coupe's brakes.  After installing a replacement valve unit on the master, what should have been an easy finish I'm stuck.  Since the middle fitting for the back wheels had been there for years it would NOT budge so I had to cut the line directly under the fitting which created my problem. I know these lines are steel, quite possibly original so I need to flare the line.  I have a cheap Stinger set and, as we all know, the size is 4.75mm.  My problem is that the line insists on slipping rather than forming a flare.  I've tried filing the outside to thin the wall slightly and put some WD-40 on the die, tightening the tube securely in the clamp and, using the smallest die, I've been trying over and over to get it to flare but the line just keeps sliding down.  I've used pliers to tighten everything so the clamp is tight but w/o luck.  Should I get a more expensive tool set or am I doing something wrong?  I'll admit to being a bit impatient as once everything is back together, I'll be able to refill the reservoir, bleed the system and get back on the road.  Thanks

[Padgett]

I find a little heat (the bake fluid I use is good for 450F) and a little kabanging plus use of the proper flare nut wrench can do wonders. Like working out a dent just need to be patient.

 

ps a little knurling might help.

Edited July 13, 2022 by Padgett

[rogold]

Maybe wrap a little tinfoil around the line where the clamp goes?

 

[fun car guy]

Sorry but this stupid issue has cost me hours, almost all summer trying to make a bubble flare on the line for the rear wheels.  I bought the most recommended tool but it won't grip the tube, just lets it slip down trough the vice.  I've tried sandpaper and even grinding down the vice to be sure it would grip but no luck. It's gotten to the point where I'm beginning to feel I shouldn't even bought the car!  I'm not gonna spend 300.00 or more for some fancy tool I'll never need again just to make one freaking bubble flare so, what to do?  Is it possible I'm dealing with a stainless tube that's too hard?   Any more suggestions? 

This is the kit I bought.

 

[fun car guy]

Padgett suggests heating to remove any temper in the metal?

[fun car guy]

So now it's apparent that I'm dealing with stainless brake lines,  Following Padgett's advice, I used a propane torch and heated the end of the tubing red hot and did manage to get it to begin to flare but not completely so I heated it again, let it cool and tried it again but it wouldn't budge.  No matter as while trying to flare the tubing, I bent it a little and while trying to bend it back, it broke off at the end.  It looks like the tubing is very hard and brittle so even with heating, resists flaring.  I'm not giving up, just going to back up and hit it again but eventually I'm gonna run out of length.  This part of the job is snowballing!

[2seater]

Way back at the beginning, I think I remember you purchased an OTC Stinger flaring kit, which is what I have used, but the above photo does not look like the same kit. It is similar, to be sure, but not the same. I don't know if it would make a difference but???

Edited August 17, 2022 by 2seater

[fun car guy]

Nope, we have the same one but this tubing is really hard and now I see, also brittle.  Should I bust the piggy bank and buy the one from Eastwood for $300.00, even though I likely won't need it again? What was your experience using the Stinger tool? I understand they now make brake and gas lines that include copper in the steel, making them easer to work with.

[2seater]

I haven’t had any issues with the Stinger tool but I wasn’t doing anything in the brake master area. Is the tube one piece between the master and wherever it goes? No opportunity to replace it with a premade line?

 

This tool is probably similar to the Eastwood and is also ~$300, but it works effortlessly, plus it makes other styles including the fuel line connections at the engine on our cars. It is a loaner from a friend of mine but maybe something similar is available for rent or loan at a FLAPS?