Lowtechprime
Retro Grouch
You need one of these for those "cheese steel" fittings... Just enough steel to rust, but not enough to provide any strength...
Fixed: Brake Master Change Nightmare, thanks to RX1900 (See pg4)
- Thread starter BrianM
- Start date
Careful here.... MWB lists them all that way but the listings for some also say '76 on and you'll need a different part number for '74-'75. That's the early double flare vs bubble flare thing. So if you have a '74 and you haven't replaced that junction block by the master, you will want to look again at the flare seats and also the FedHill tech note about common misthreadings.
If you do have flare type mismatch, although Midwest doesn't have the early-style tube (bubble on one end, double on the other) up on their storefront I would bet long odds that if you call they'll have some and just haven't listed them yet. If they don't, any local brake shop will be able to make one up for you in about five minutes, the hardest part will be convincing them that you really do need a tube with a SAE flare nut on one end and a M10x1.25 bubble flare nut on the other.
Also be aware that M10x1.25 is an unusual size, most European cars use M10x1.0
FedHill carries both, Midwest carries the 1.25, but I still long ago formed the habit of saving these flare nuts whenever I scrapped a hard line.
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Dan Sarandrea (Phila)
Waitin' On Parts...
If you have a refrigeration supply house or hydraulic supply house nearby, see if they stock copper flare gaskets:
ng_randolph
Bjorn H
And here Midwest-Bayless confirms that the early brake failure switch block uses inverted flare rather than bubble flare.
Steve Thomas
True Classic
I am confused. As I understand it OP has a 74 and per the first pic, it has a block that takes the rear line and one front and looks like it is the early brake failure switch block. The failed line was the other front and a proposed solution was to add the other union block and short line as used on later cars. I was not aware of the flare differences 
. But if there is a problem it would be either at the master port or the union block assuming that the short line has the same [either type] on each end. Per post#62 the OP probably needs a short line with a different type on each end. But this should have nothing to do with the existing switch union - not messing with it at all?
Per #66 below - if all master are bubble then the short pipe from a later car should be perfect as it will have bubble at both ends - which is what you need.
. But if there is a problem it would be either at the master port or the union block assuming that the short line has the same [either type] on each end. Per post#62 the OP probably needs a short line with a different type on each end. But this should have nothing to do with the existing switch union - not messing with it at all?Per #66 below - if all master are bubble then the short pipe from a later car should be perfect as it will have bubble at both ends - which is what you need.
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ng_randolph
Bjorn H
Looking through this thread, you now have a master cylinder that take bubble flares (as they all did), a new (to you) junction block that takes bubble flares, but did you reuse your old '74 short brake line (from master cylinder to junction block) that has bubble flare at the master cylinder end, but double flare (inverted flare) at the junction block? If so, that would explain the leak you pointed to:
BrianM
'74 - Blue Bomber
On my '74 there was no junction block for the left front brake line, it went direct to the master. I purchased the new break line, junction block, and "long line", going from master to the junction block from MWB? I'm taking the junction block section apart today to double check this wasn't just me screwing up.Looking through this thread, you now have a master cylinder that take bubble flares (as they all did), a new (to you) junction block that takes bubble flares, but did you reuse your old '74 short brake line (from master cylinder to junction block) that has bubble flare at the master cylinder end, but double flare (inverted flare) at the junction block? If so, that would explain the leak you pointed to:
Yep, mine too. The lines to the rear and to the right front go to the junction block.
rx1900
1981 X1/9
Correct !! As some folks here seem to be confused about this....yes ....that was the correct solution. All of the parts you purchased should have had m10 x 1.25 threads and bubble flares. Assuming the parts you got were...and did not have damaged threads.....you should have been just fine !!
Sadly.....I suspect you did. As others have said...it is super easy to cross-thread these fittings !!! When you assembled that particular now-leaking junction.....did the fitting screw in straight - and easily by hand - until it bottomed ? Or did you have to crank it in with a wrench ?
If - I suspect - you cross-threaded it - it likely did not tighten enough for the bubble to seat all the way into the fitting. And of course will now leak.
Suggest you pull that junction apart and look closely at the threads on the line and inside the junction block.
Having said all that......now there is a slight chance that..... sometimes.....if not cross-threaded....a joint that leaks under pressure...is caused by re-using a line too many times...especially if it had been previous overtightened and the flare has been squashed too much. Or if the seat has some scoring. Sometimes...in this case....one of those "copper flare washers " - like Dan referenced to - can be used with success to achieve a leak-free joint. But note that you need a 3/16" one - not a 3/8" one that Dan pointed to.
I have found it is always a good idea.....that before attempting to thread a brake line nut into a fitting....to first grab a m10 x1.25 bolt and nut. Does the loose nut spin freely and fully onto the brake line nut ? Does an m10 x 1.25 bolt screw straightly and freely into the female part of the junction block or brake master ? Sometimes...a tap or die can be used to correct any slightly mangled threads...but use good judgement there....
If you -or anyone out there - ends up needing a new jumper line - I do have some here I made up. See the pics below. They are very difficult to make. Getting a proper bubble flare requires a very expensive flaring tool ....and a LOT of practice before you perfect it. and the proper Fiat line nuts are not easy to find. Be warned....as the Fiat m10 x 1.25 line nuts are indeed slightly different than some of the other m10 x 1.25 line nuts you may find on Ebay or from on-line brake bits suppliers. And...bending the lines...especially in this case where the bends are close to the ends...is very tricky....
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Rupunzell
Bernice Loui
Bubble flares are not difficult to make, it is much a matter of using a quality flaring tool.
Facom 347:
Which has been copied, sold by Eastwood:
www.eastwood.com
~Any good ?
Imperial makes a portable bubble flaring tool (# 293F), works where the Facom does not.
factorysupplyoutlet.com
The tube nuts used on Fiat are M10x1.25 Long, these are not common or standard on many newer cars today. It was common on many European cars made during the same era as the exxe.
Use Copper/Nickel tubing specifically designed for brake hydraulics. This has proven to be the easies to work with, more corrosion tolerant than plated/coated steel. 3/16" OD x 0.028" thick wall for Brakes, 1/4" OD x 0.028" wall for clutch hydraulics.
Note on the clutch master. The fitting is a special M12x1.25 long tube nut.. Not sold by any of the usual suppliers. If this tube nut is damaged, procure a good-used replacement or make one on a lathe.
Brake line can be bent using the usual tube benders or tube bending pliers:
Not just the tube end that must be in good condition, the bubble or SAE 45 degree double flare seat must be in good condition or the joint will never seal properly..
Don't forget the anti-seize on the threads to make future work on the tube nuts significantly easier.
Brake failures are no fun at all,
Bernice
Facom 347:
Which has been copied, sold by Eastwood:
Eastwood Professional Brake Line and Tubing Flaring Tool
Create 3 kinds of precision flares, in 5 sizes of tubing
www.eastwood.com
Imperial makes a portable bubble flaring tool (# 293F), works where the Facom does not.
Imperial Stride Tool METRIC BUBBLE FLARING TOOL (1 EA / EA)
At Factory Supply Outlet , we aim to cut your MRO Spend in just a few clicks. We carry Lubriplate, Busch, 3M, and over 200 different Brands to serve your needs!
factorysupplyoutlet.com
The tube nuts used on Fiat are M10x1.25 Long, these are not common or standard on many newer cars today. It was common on many European cars made during the same era as the exxe.
Use Copper/Nickel tubing specifically designed for brake hydraulics. This has proven to be the easies to work with, more corrosion tolerant than plated/coated steel. 3/16" OD x 0.028" thick wall for Brakes, 1/4" OD x 0.028" wall for clutch hydraulics.
Note on the clutch master. The fitting is a special M12x1.25 long tube nut.. Not sold by any of the usual suppliers. If this tube nut is damaged, procure a good-used replacement or make one on a lathe.
Brake line can be bent using the usual tube benders or tube bending pliers:
Not just the tube end that must be in good condition, the bubble or SAE 45 degree double flare seat must be in good condition or the joint will never seal properly..
Don't forget the anti-seize on the threads to make future work on the tube nuts significantly easier.
Brake failures are no fun at all,
Bernice
BrianM
'74 - Blue Bomber
OK, I pulled the block out today and took pics below, all looked ok. Looking back I think the problem was I bolted the block to the assy first then tried to put in the cross over pipe. The bend being slightly off I was not able to get it perfectly straight. I reinstalled the crossover pipe, in the block now free from the bolt, hand threading it until it bottomed then did the same on the lower. Bolted the block loosely on the assy and gave them a final tighten, there was a slight leak at the bottom pipe but one more crank with the wrench stopped it. No leaks! Unfortunately it was just because there was by now, no fluid in the system. It started leaking again, at the top, when I started bleeding the system :-(
I'm guessing the first crooked tighten may have damaged something on the flare.
So now the whole thing has to come out which scares me as all the other connections don't leak, now.
I'm going to try a new over the top pipe, and block, (not too expensive) and try again. I may give the copper washer a try. Looks a bit fiddely for under dash work.
I'm guessing the first crooked tighten may have damaged something on the flare.
So now the whole thing has to come out which scares me as all the other connections don't leak, now.
I'm going to try a new over the top pipe, and block, (not too expensive) and try again. I may give the copper washer a try. Looks a bit fiddely for under dash work.
Steve Thomas
True Classic
Its not a great bit of design - no matter the sequence. Yes, I would install the line first, both ends finger tight and perfectly square, then fully tightened, and then tighten up the bolt. In terms of design, the issue is that the block does not have a definite position - it can rotate. Even after the line is fully installed and you tighten the bolt, the block will try to rotate and stress the line. If, as you say, the block bolt is tightened first, then the line will need a slight bend correction so the the fitting lines up perfectly. I hate "perfect" but unfortunately, this is one area where it is required!
rx1900
1981 X1/9
Hmmm.......this is a bit odd. I was expecting to see evidence of cross-threading.....but not seeing anything....
The top line nut looks fine...except for some rounding of the flats for a wrench.....did you do that or got it that way ?
In the first pic of the junction block.....it might be an illusion .....but almost looks like the flare was not seating squarely ?......and something strange from about 12 o'clock to 3 o'clock. ...is that raised corrosion ? And hard to see...but no sign of cross-threading on the threads inside the junction block ?
If...all looks okay.....it might just be a case of two used parts from different cars...that dont want to play nicely together. I suppose there is a 50/50 chance that one of those "copper flare washers"....just might seal that junction......Might be worth a shot ??
I replied to your PM.
Alex(Tenerife)
True Classic
Is the problem that the flare is not on straight?
I rotated and cropped your pic and then I drew a light red square on the image to check and to me it look like the flare is a few degrees off. You can see ifs closer tot he red line on the right than on the left.
Maybe its nothing, but looks odd to me. Was this a newly made up solid pipe?
I rotated and cropped your pic and then I drew a light red square on the image to check and to me it look like the flare is a few degrees off. You can see ifs closer tot he red line on the right than on the left.
Maybe its nothing, but looks odd to me. Was this a newly made up solid pipe?
Rupunzell
Bernice Loui
Normal, how this design functions. Slop between the tube nut to flare end is allowed to float-fit the seat. If there is no float, the flare tube end cannot conform to the seat position then seal. Notice the end of the tube nut flat out a bit due to the forces involved with pressing the tube's flare into the seat. The once sorta half spherical bubble flare has been mushed into the shape of the seat to form a "seal". This is why both Girling bubble flare and SAE 45 degree double flare (tiny sealing area) does not re-seal well once taken apart.
The Girling bubble flare newly made on copper/nickel tubing , it is half step to the SAE 45 degree double flare.
Previously mentioned, if a Girling bubble is taken apart flares then does not seal upon re-assembly, apply a copper flare gasket to aid in sealing.
Copper flare gaskets usually work to seal a problem flare joint, copper gaskets do not work on SAE 45 degree double flares as the sealing area is too small. These copper flare gaskets are designed for 45 degree single flares used in the HVAC and similar systems, the other variety is designed for 37 degree single flares very common on aircraft and commercial-industrial hydraulic systems up to 3,000psi operating.
Bernice
BrianM
'74 - Blue Bomber
I'm getting some new lines and will try again. I think I just got some bad luck and used parts that don't like each other.
Rupunzell
Bernice Loui
Not just new lines with new fittings, those joint blocks will be damaged from the previous attempt to assemble. They will need to be properly repaired or replaced.
Two parts to all this "plumbing" stuff,
Bernice