Does anyone know the flare size/type of the brake end near the master cylinder or ABS

[Yukonvic]

Can anyone tell me what kind of flare type are at the connections of the middle brake line especially near the top by the master cylinder/ASC connection? Is it standard or metric ? or ?

 

[DeRocha]

I'm in the same boat and also need help with the ABS brake line fitting & flaring.

The driver's side hard line coming from the ABS controller to the front brake hose has cracked and needs to be replaced. The Tubing is a standard 3/16" with a standard fitting/connection at the hose. Unfortunately the fitting at the ABS controller is much larger (Metric?) and doesn't appear to have a double flair like the std connection. I called my local dealer and they don't carry this line. I picked up a std flaring tool, but the flare doesn't look like the one I removed from the vehicle. Can anyone shed some light on this?

Btw the ABS controller has 3 output hard lines. Front left, Front right, and Rear. The rear fitting is a std 3/16" (all the way back to the rear brake cylinders) while the fronts appear to by much larger (possibly metric).

 

[Longjohn119]

Mine is a '91 but it uses a bubble (reverse) flare, I don't remember the size offhand, only that no one in my area had any brake lines available with the right size nut and type of flare ... so what I ended up doing (I was running a new line from the master to the rear and bypassing the never worked right anyways RABs valve) was renting a double flaring tool and you only do the first step of making a double flare ... worked like a charm first time and already did a serious test of the brakes last Friday when an illiterate truck driver decided at the last minute he was turning the wrong way onto the Interstate and cut over into my lane after I had the passenger side fender alongside his trailer .... Braked so hard that the outboard motor on the boat I was pulling flipped up and broke the bungie cord and slammed back down bending up the tilt lock and lever for the shallow water drive ....
And no the a$$hole didn't even stop o see if I was alright so he got a 3/4 full can of Mt Dew across his front window as he turned on the on ramp ... dude owes me about 100 bucks to replace the bent and broke parts on my motor and was lucky he didn't total out my '91 Bauer with only 57,000 on it (I woulda had to cry if he had)

 

[DeRocha]

Thanks for the info. I had picked up a double flare tool, but couldn't make any decent double flares. The first step was perfect, but the second were it he reamer creates the double flare would get off center and mangle the line. I did notice the first part of the flare looked very similiar to the original. I will take another look and see if I can get that to work...

 

[DeRocha]

Found it ...I searched the net and determined the connection is a metric Bubble flare. Making such a flare is easy: if you are in possession of a standard 45 degree double flaring tool, the bubble flare is what results after the first half of the operation. Simply stop there, and you have the bubble flare which will seat nicely at the bottom of the hole. If you continue, inverting the form tool and finishing the job, you then have the more familiar double flare used by the US automotive industry.

 

[Cali' Explorer]

Isn't that what LongJohn just said?

I hate having to mess with brake lines... hopefully I won't have to for a while, hehe.

 

[Longjohn119]

Like I said, mine's a '91 .... DeRocha's is a '93 and he did the right thing looking it up and verifying it ... You just never know with different years, especially with the transition from RABS to full ABS going on about that time ...

And I can't take credit for it, a retired gentleman working part time at an O'Reilly's Auto Parts gave me the idea and the flaring tool (Free to use but a deposit) ... Cripes I wasn't even aware the Euros were using a different flare

Still mad at that damn truck driver ..... Fortune410 was right though, I didn't miss the RABS a bit and probably was better off without it ... ass end of the truck started to slide out to the right a bit but I think that had more to do with the boat trailer with no brakes pushing it into a jack knife as I was frantically braking and trying to turn to the left to avoid him taking my front end off .... at least I know all my flares and flex hoses are good now, I'm used to manual brakes and I really stomped on them, anything bad woulda popped like a zit ....

 

[DeRocha]

I stumbled across the best solution while at the auto parts store. I spied their brake line wrack and noticed they had 3/16" metric lines (go figure) . Immediately I knew I was going about it all wrong. I had been trying to modify a Std line to have bubble fittings when I should have done the reverse (modified a metric line to have a double flare). Anyway I bought a 3/16" metric line with bubble flare connections. I then cut off one end with my tube cutter, inserted the old ABS and new 3/16" fittings. I then used my double flare tool to double flare the std side. It worked perfectly with no problems or leaks.

BTW even though the bubble flare has the same shape as a double flare's 1st step it is not the same internally. If you look into a bubble flare you'll see the flare part is hollow while the 1st step of a double flare is not. This hollow area allows it to be easily crushed to form a seal when the fitting is tightened. I'm guessing you could do the same with the double flare 1st part, but it would take a lot more torque to make a good seal.

 

[Peter Westling]

I was redirected to this thread, read the info, really good. I just wanted to add some images to illustrate the difference between bubble and double flares.

picture one:
The bubble flare is on the top, and the double flare (with the purple tape) is on the bottom

Picture two:
This is just another angle. The double flare on the left, and the bubble flare line on the right.

 

[410Fortune]

Oh this is a fun topic. When I converted my 88 to rear discs and a no frill 95 Explorer master cylinder I fought the brake line fittings.

I eventaully had to plumb a new hard line to the rear axle.
The 88 BII and some early Explorer's had a huge standard bubble flair for the rear axle.
In order to make the jump to a metric bubble flare to the standard line it would have required a stack of 3 or 4 adapters. No thanks!

What a PITA. The 4wabs system uses the later metric flare lines.