Which Brake Flare Type?

[ede smith]

2001 Buick Cenrtury

Wanting to buy a brake flaring tool to replace my lines but I am getting conflicting information. A prior post here says it's a DIN bubble flare (Same as ISO bubble flare), but I've also read it is an inverted or double flare. Which one is it?

 

[ede smith]

Well ask AI and you will get 3 different answers, It went back and forth from double flare to DIN bubble flare and even using different AI chat bots. It also said there was a chance that they use both. I am leaning towards that they are all DIN bubble flares which are oddly utilized on European vehicles.

Now to figure out a decent flaring tool, then decide on pre-bent lines or getting a roll of Ni Copp tubing.

Some folks use the first step of a double flare bender in lieu of a special DIN bubble flare bender which I'm not sure is correct as they sell special ISO/DIN bubble flare tools. Can anyone confirm?

 

[ulycyc]

GM uses double flare brake lines especially on older models like yours. Bubble flare may be on GM cars made overseas. Making double flares will be hard to make without splitting if you buy cheap rolls of brake line. I would spend the extra money and buy ready made custom fit lines from Inline tube or SS brake. Both are around $200 for a complete set

 

[ede smith]

It's amazing how many different answers I have been getting and would have expected double flares to be the most obvious.

I think to avoid the confusion I will probably get pre-bent lines.

Here is the last answer I got:

Confirmed: 2001 Buick Century Uses ISO (Bubble) Flares​

1. Buick Forums Expert
   A trusted user shared from direct experience:
   
   

   “They are ‘Bubble’ or ‘ISO’ flares, not a double flare… Despite what the internet tells you, you need a bubble flare tool.” Buick Forums

2. Buick Reatta (Similar GM Models)
   A detailed discussion—though about another model—makes the distinction clear:
   
   

   “My Reatta… uses a flare called an ISO flare. … Do not let the counter People tell You that all that is, is a double flare. It is not and They can NOT be interchanged.” AACA Forums

3. Reddit Confirmation
   In a conversation about GM brake line standards:
   
   

   “Older brake lines require a double flare… But newer GMs (mid‑90s and up) use a bubble flare which is a different flaring tool.”

 

[ulycyc]

"AI" is as good finding the correct parts as finding a replacement wife. Yes buy the pre-bent lines

 

[ede smith]

Okay, just got done with transmission pan drop and 7.5 quarts of new fluid.

I looked at Inline tube website today and if I do this, I will get stainless—which will outlast the car—they have two other options for pre-bent lines. One is with flex, one is without. They will price match the one that they are selling on ebay for $236, it has
no flex lines though. As I understand it, the flex lines will ensure a better fit near the ABS control module/Master cylinder area. Can anyone speak to this if they have gone through the work of replacing their lines?

 

[chem_man]

My recommendation is to purchase a 25 foot roll of NiCopp in each tubing size you will need along with the required brake nuts/fittings, and then get one of the loaner brake flare tool kits from Advance/Carquest, O'Reilly or AutoZone, and make your own lines.

NiCopp is much, much easier to work with compared to steel or stainless steel lines, and will last far longer than any steel or stainless steel brake line. Making flares on NiCopp is also much easier! NiCopp is stronger than steel or stainless steel, is DOT approved for brake lines and does not need special tools for making curves or bends in it.

You can order NiCopp online from rockauto.com or amazon for extremely reasonable prices as compared to getting it locally at a brick and mortar parts store.

 

[ulycyc]

I've done many cars with rolls of brake line and the proper tools on a lift. But for a novice working in his driveway ready fit lines is the way to go. Also will cut the time laying on your back in half. Also getting the correct fittings and unions can be a headache and waiting for the post office to show up.

 

[ede smith]

My recommendation is to purchase a 25 foot roll of NiCopp in each tubing size you will need along with the required brake nuts/fittings, and then get one of the loaner brake flare tool kits from Advance/Carquest, O'Reilly or AutoZone, and make your own lines.

NiCopp is much, much easier to work with compared to steel or stainless steel lines, and will last far longer than any steel or stainless steel brake line. Making flares on NiCopp is also much easier! NiCopp is stronger than steel or stainless steel, is DOT approved for brake lines and does not need special tools for making curves or bends in it.

You can order NiCopp online from rockauto.com or amazon for extremely reasonable prices as compared to getting it locally at a brick and mortar parts store.

I was going to do that, but was trying to figure out the correct flare—and then ulcyc's recommendation changed my course. Have you replaced yours with NiCopp and if so which flaring tool did you buy? The Lisle flaring tool I was looking at was $70, the NiCopp roll with some fittings was.$30. A decent 3/16" tubing bender like the Rigid one is $70, although it sounds like that wouldn't be necessary. At $100 that's about 1/2 to 1/3 the price of preformed lines which certainly is a savings, although time should be a factor too as I will be doing this on my back on the concrete driveway.

Stainless is much stronger then NiCopp, I would have thought it would on par with longevity, but apparently NiCopp does win in this department and I am in a road salt state.

I am very indecisive at this point!

 

[ede smith]

I've done many cars with rolls of brake line and the proper tools on a lift. But for a novice working in his driveway ready fit lines is the way to go. Also will cut the time laying on your back in half. Also getting the correct fittings and unions can be a headache and waiting for the post office to show up.

Yeah I will be working on my back in the driveway. What are your preferred tools for this? I think I left my brake bleeder wrench and am trying to make sure I have everything on hand before beginning!

 

[ulycyc]

No special tools needed except Line wrenches. Also work clean. Wash all down with spray brake clean before removing old lines. Make sure the caliper bleeders are not frozen. If so address that with new bleeders or calipers.

 

[chem_man]

I have replaced brake lines on 4 different vehicles using NiCopp, including to from the ABS unit on a 1999 Silverado and a 2004 TrailBlazer. I actually had to run a new line from the ABS unit back to the rear axle in the Silverado and I had to feed the line through the driver's side rail frame and using the NiCopp, it was a piece of cake.

I used a loaner brake line flaring tool kit from Advanced Auto. It worked just fine. I cut the NiCopp using a small tubing cutter I bought at Home Depot or True Value Hardware, and of course I used tubing fitting wrenches at all the connections. I did have to remove the mounting bolts for the ABS unit on the Silverado and TrailBlazer in order to get enough room to place the flare nut wrench and turn it. I did not strip any fittings. I did have to make 2 or 3 trips to various auto part stores in order to get the proper brake line nuts, but that allowed me to stretch and get limber again.

I have since purchased an OTC Brake Line Flaring Tool kit from O'Reilly Auto Parts. The part number of the kit is 6503, and I like it. Also, flaring NiCopp line is much easier than steel or stainless steel lines.

The only problem I can see with preformed lines, is that if you run into an obstruction or need to wiggle the line in order to get it where it needs to go, you can waste a lot of time trying to wrangle that line into place. I have not run into that problem using bulk NiCopp tubing.

I too live in a state where they use lots of salt in the winter!

Whichever way you go, Good Luck!

 

[Buick City Bert]

Just a little story about pre-bent lines, my daughter had a 2000 Impala, same chassis as the Regal, and needing to replace all the brake lines I bought factory bent lines. They were good, mostly, except that the one that went all the way to the right rear was long and very "twisty" and followed a convoluted route through the engine compartment from the anti-lock unit (Installed before drive-train on assembly line).
Be prepared to cut it in half (sort of) in order to wiggle it into place, and then using a flare union reassemble it in place (flare it on the bench, you will be glad you did).
After the expense, and trouble of that adventure, I had OEM, steel brake lines again, but with a union in the one.

Never again have I bought pre-bent lines, they are good for body off restoration jobs, not repairs. For repairs I always use CU-NI which flares easily, bends by hand if you don't have tools, and corrodes at a much slower rate than steel.
We ended up having a large selection of tubing tools here, including European bubble, and inverted double flare, GM used both!
If you wonder what your car has, go to the parts store and ask to look at a caliper, it will be evident when you look at the inlet!