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General Tech Standard for the Girling Bubble Flare

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spits

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Greetings,
I've been in search of the standard that defines (or defined) the Girling bubble flare geometry that's used on our Triumphs along with other vintage British vehicles. I've reviewed the SAE J-2879 (the current, nominal concave double flare) and the ISO 4038 (the European bubble with the 90 deg to tube back angle), but the Girling, aka "SAE single", "SAE bubble", "SAE convex", "Imperial bubble", etc., flare in question isn't specified.
Any insights would be appreciated.

Thanks!
Paul
 
Paul, if you're planning to make a tool, if you make 2 I'll buy one! Likewise, if you find a tool let us know. Those old fashioned flares are always an issue when doing brake work. I can get the modern flares to work, but it bothers me knowing they are not right!?!
 
I use a tool that makes the square-back bubble flare. The flares seem to mate and seal well with fittings originally designed for the older bubble flare design.

Ed
 
Thanks. Thatuniversal flare is interesting and I’ve heard folks have had success with it,but, I’m always leery about something that isn’t the ‘real deal’. That’s part of the reason I’m looking for thestandard, i.e. what is the geometry supposed to be. I’ve heard of others with Ed’s experiencewith the DIN/ISO bubble, but in that case the geometry really shouldn’twork! The flare face has a 115 degincluded angle, i.e. it’s ‘flatter’ on the face than the Girling bubble (basedon empirical observations of the actual lines in our cars).
Thanks for the replies. I’m going to keep looking for the actual geometry. I’ll keep this thread current based on what Ifind.
By the way, I’ve heard great things about the turret styleflaring tools that Eastwood and others sell. It is able to make the Girling flare, supposedly. I just don’t know if it’s ‘real’ or it justworks in spite of not being truly compliant to a spec.
Best,
Paul

 
Good stuff. Thanks gents.
I dropped FedHills a note about the standard that I'm seeking. I'll follow-up if/when I hear from them.

Thanks.
Paul
 
Paul,
For sure keep us posted on any info you get back from FedHills. Especially if you can get a flaring tool from them or they tell you where to get one. I have the Eastwood tool that makes pretty much all modern flares, and had planned on just finding the flare option on that tool that most closely resembles the flare that comes off of a TR line. I've had good luck doing similar in the past, but if there's a "real" correct flare tool available, I want it.

Thanks,
Robby
 
Alfred E. Neuman said:
Paul,
For sure keep us posted on any info you get back from FedHills. Especially if you can get a flaring tool from them or they tell you where to get one. I have the Eastwood tool that makes pretty much all modern flares, and had planned on just finding the flare option on that tool that most closely resembles the flare that comes off of a TR line. I've had good luck doing similar in the past, but if there's a "real" correct flare tool available, I want it.

Thanks,
Robby
Click to expand...

Take a look at FedHills flaring tool rental: https://store.fedhillusa.com/toolrental.aspx
 
The bubble flare is easily made as its the first step in making a concave flare . Any good brake line flaring tool will ( with practice) make a suitable bubble flare that works with our British cars. If you have a reason other than practicality and function , so be it !
 
I have two flaring tools: the Ridgid 345 Double flaring tool, which can make doubles or bubbles or square backed bubbles.

Later on I acquired the Eastwood tool, which IMO makes better flares more easily. The final flare appears to be the same as a MOPROD Universal flare (as Moss sells). These flares seal in either double or bubble applications:

EastwoodFlareTool.jpg
FlareFinal.JPG


I'm not too exited over making an exact original flare as much as making one that seals. If it seals, it's good.
 
Greetings folks,
I thought that I’d reply following a conversation with Tim at FedHills. I had emailed a question and Tim responded with a phone call. We had a good conversation on the topic; he comes across as a guy who’s genuinely interested in the material.

Recognize that my interest is both academic and practical. As an engineer, I need to ensure that I’m working with a standard that is being complied to; practically, I’m interested in a braking system that simply works. Tim couldn’t identify the standard to which Girling bubbles were made; he believed that it was an obsolete British standard. On that front I’m still searching.

The creation of a compatible bubble flare using the FedHills turret flaring tool—or any of the other flaring tools that I’ve seen currently on the market—is to make the initial deformation for the SAE double flare and then simply stop. The geometry is, therefore, ‘uncontrolled’ and the efficacy metric of the flaring tool’s flare is simply that it doesn’t leak.

So, I’ll continue to scratch my academic itch, but the consensus seems to be that the first-step-in-the-SAE-double-flare approach works and, therefore, it’s good enough.
 
Brinkerhoff said:
The bubble flare is easily made as its the first step in making a concave flare . Any good brake line flaring tool will ( with practice) make a suitable bubble flare that works with our British cars. If you have a reason other than practicality and function , so be it !
Click to expand...

Agree. I've been using a cheap flare tool to make the bubble. (The challenge is to keep the bubble perfectly in line when flaring.) I use kunifer lines however and it might be a different story with steel. The softer material seems to take its final form when tightening the net.

Tom
 
I had a terrible time making a bubble flare in hard steel line; the kind you buy at FLAPS with connectors already installed. I finally had to borrow an expensive tool (which looks just like the cheap ones) to get a bubble that would seal. Still looked awful, but was functional.

My assumption is that it would be easier with the softer steel line sold by the foot. But I only needed that one (my TR3 doesn't use bubble flares and I sold the Sports 6) so I've not had occasion to try it.

Girling was something of a pioneer in automotive brakes; it may be that there was no accepted industry standard for the bubble flares they used. Seems improbable today, but things were a lot different in the UK back then. Monopolies were actively encouraged rather than being forbidden, as they are in the US today. And Girling would not want anyone else being able to make "proper" brake lines to their specification.
 
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