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Sun Jan 27, 2013 7:45 pm

Can I use a standard flare into a vw wheel cylinder or does have to be a bubble flare?

Sun Jan 27, 2013 8:15 pm

I wouldn't use anything but a bubble flair.

If you have a flaring tool that does single flares, any auto parts store can get adapters that you can screw in to mate the two different end types...but it is just one more place you could get a leak.

Mon Jan 28, 2013 5:48 am

Vanapplebomb wrote: I wouldn't use anything but a bubble flair.

If you have a flaring tool that does single flares, any auto parts store can get adapters that you can screw in to mate the two different end types...but it is just one more place you could get a leak.

My flare tool only does single. I seem to think on my last rail I used the single flare, but I remember it had to be really tight to seal. Just trying to do this one right.

Mon Jan 28, 2013 6:06 am

EURO BUBBLE

Mon Jan 28, 2013 6:24 am

Chris070780 wrote: Vanapplebomb wrote: I wouldn't use anything but a bubble flair.

If you have a flaring tool that does single flares, any auto parts store can get adapters that you can screw in to mate the two different end types...but it is just one more place you could get a leak.

My flare tool only does single. I seem to think on my last rail I used the single flare, but I remember it had to be really tight to seal. Just trying to do this one right.

Single flares are illegal for brake lines. There are 2 approved flare designs. Double flare and Bubble flare. VW uses bubble flare. Glad to hear that you want to do it right.

Mon Jan 28, 2013 6:33 am

Ok one last question. I have a Jamar Master cylinder. On the clutch side I used a 1/8"NPT to inverted flare to connect MC to the lines. Is this the same adaptor that I should use for the brake side? Inverted Flare work with bubble?

Mon Jan 28, 2013 9:28 am

No, Inverted flare is for double flared lines.

You require an iso style fitting.

Mon Jan 28, 2013 12:38 pm

Quote: Single flares are illegal for brake lines.

Yup, there is a reason for that. They do not stand up to the pressure well. They are also prone to cracking for whatever reason. Either way that adds up to a hydraulic failure. We are working on cars here...not trains and semi trucks which have a fail safe braking system. No hydraulic pressure = no brakes.

Is it really worth the risk?

Mon Jan 28, 2013 1:07 pm

My goal was to convert everything to double flare but with stock wheel cylinders this is not possible is it?

Mon Jan 28, 2013 1:32 pm

Chris070780 wrote: My goal was to convert everything to double flare but with stock wheel cylinders this is not possible is it?

Stock wheel cylinders are a double flare. Just be careful because there are two types of double flares. The asian style an the European styles. They are a slightly different shape. VW obviously uses the the European metric bubble style shown above in the picture on the right.

Mon Jan 28, 2013 1:36 pm

Auto parts stores sell flaring tools so you can make your own. It is pretty easy. I don't own my own, but I borrowed one for a different project. Pice of cake to use.

Here is a good youtube example of how it is done...

Mon Jan 28, 2013 1:40 pm

I was trying to convert to US spec same flare as pic in left. The jegs rpv uses that type. Makes for easy install.

Mon Jan 28, 2013 2:13 pm

I really think you should stick with the bubble flare as seen on the right man. By the time you buy all the adapters you need to screw into the brake hardware, you could have just gotten the bubble flare tool. 20 bucks will get you a flare tool where as adapters are like 2-3 bucks a pop.

Tue Jan 29, 2013 4:50 am

Vanapplebomb wrote: Auto parts stores sell flaring tools so you can make your own. It is pretty easy. I don't own my own, but I borrowed one for a different project. Pice of cake to use.

Here is a good youtube example of how it is done...

Although many people cheap out and try to make bubble flare using the double flare tool, the flares are not correct. The angle formed on the bubble is wrong as can be seen in this photo.

Do it right and either borrow, rent or buy the proper bubble flare tool. Also do not try to flare the lines that come in the Beetle brake line kits or stainless lines. They are too hard. Copper is also illegal. You can use standard 3/16 brake line available at any FLAPS. It fits the fittings and tool perfectly. Roughly $30 for a 25 foot roll. No need to try to find metric sized line. I reuse my factory fittings when replacing lines as there are bubble flare fittings that are correct and some that are almost correct. Metric and standard thread. The standard, almost correct, seem to work until you tighten them down. Then the threads start pulling out.

Tue Jan 29, 2013 5:29 am

Thanks for all the help. It does seem better just to stick with bubble flare. Can anyone recommend a 10# pressure valve that already has bubble flare ends? I got my last one from jegs and it has inverted type flare.

Tue Jan 29, 2013 11:06 am

You can get different angled dies for the auto parts stores if your that picky. It isn't a spot on match, but the soft brake lines mush down enough for a nice tight seal. My buddy has been using his el cheapo tool to make bubble flares that have held up fine for 12 years.