brake pipe adapter

[Valcuda]

bay4.JPG (96.55 KiB) Viewed 1288 times

Does anybody know where in this country one can order brake pipe adapters like the ones in the picture going to the master cylinder? I've looked in vain on-line and my local garage can't get them. The thread going into the master cylinder is 1/2" X 20 UNF and the internal female thread from the brake pipe union is, according to my notes, 3/8" X 24UNF.

[Pete]

Try USAutomotive, or if you know specifically what you require, eBay can be of use too.

[Dave999]

if that's the original style master cylinder for the car then the tube nuts were probably the correct size for the holes originally
and someone has made do with what they could get and an adapter

my master cylinder has a big connector and a smaller connector that go right in without adapters

i'd suggest this is standard mopar stuff

the internet says

Small one is 1/2"-20. Large one is 9/16-18. Both for 3/16 brake line

inverted flare

potentially these

http://www.summitracing.com/parts/aaf-all50114

http://www.summitracing.com/parts/AAF-ALL50115


but can't promise, didn't buy that stuff


as i just re used what was there


Dave

[Dave999]

ah the ports on your master are both the same size.

are you replacing the adapters or just looking for tube nuts to go into them?

id order some from https://automec.co.uk/collections/fitti ... ttings-unf

and send back the ones that don't fit

you can start them into the thread without taking them out of the poly bag

they do a 1/2 x 20 3/16-pipe, tube nut


cut off the ends put new ends on flare and bolt straight in rather than have adapters

or phone them, send them one and they could make the adapters


Dave

[Valcuda]

Following on from Dave's idea, I ordered a pair of 1/2" X 20 nuts to fit a 3/16" dia pipe. I actually found Car Builder Solutions in this country for this. They fit the new master cylinder OK, ie, screw right down leaving about a millimetre between the nut head and the M/C body. But I have a further question.

What is the actual sealing surface? Is it where the conical surface of the nut inside bears against the conical surface inside the M/C port? Or is it the thread surface? On the original M/C, from the photo, because of the exposed thread, I guess one or other of the threads is tapered, as in standard plumbing applications. But the new nuts don't look tapered...

[MattH]

I think its the conical surface, hence if you get a flare off centre they leak, lots!.

[Dave999]

if you a doing away with the adapters Matt is bang on correct
but its the sandwich of nut surface- pipe flare - seat all clamped together that seals

you need to set the end of the pipe with an inverted flare of one of 2 types dependent on MC pipe seat

you basically flare the pipe out and the fold half of what is flared out back in onto itself to make double/inverted or bubble flare end with the hole in the middle.

machine mart/halfords flare kit and a bit of practice make 4 or 5 in scrap pipe then do the bit on the car
this would do the biz comes with pipe cutter hence 10-15 quid more
https://www.halfords.com/workshop-tools ... gKmbfD_BwE

or ebay for much cheaper. you need a small pipe cutter though

the outer of the flare stops the tube nut coming off the pipe
the inner fold presses into the seat in the MC
and as you do it up the seat contour gets mashed into the end of the pipe pushing open the hole (in the bubble section into nominally the right size for the brake fluid port) or sealing up the double/inverted flare against its contoured seat

all seals up ok.

peer into the mc port and compare with this picture to see if you need double or bubble flare

Bubble is DIN/euro spec double/inverted is SAE/US/JP spec



dave

[Dave999]

PS check also that the thread goes to the base of the port in the master cylinder

if it does no bother tube nuts with a "lead" or "no lead" will work

if it doesn''t and the unthreaded part is narrower than the thread you need tube nuts with a "lead" otherwise you won't clamp the flare as the nut will run out of thread before it does

with lead on right without on left



i'd be inclined to crack on and see how you go

stick some kitchen roll around the dry clean new pipe ends and stand on the brakes, its a fine indicator of leaks, greasy mark and you know it needs doing up or doing again