Flare nut detail for 1/4'' pipe - urgently needed.

[xXxPARAGONxXx]

Does the '20' refer to 20TPI?

yes.

this is a common fitting.

if u google "1/2-20 brake line fitting", ull find plenty online.

 

[Pinger]

yes.

this is a common fitting.

if u google "1/2-20 brake line fitting", ull find plenty online.

These?

10pc Steel Male Brake Pipe Union Short Fittings 1/2" x 20 UNF for 1/4" Brakes | eBay

1/2" x 20 UNF short male brake pipe fittings. Size of the male fitting - 1/2" x 20 UNF (short). Male brake pipe fittings.

www.ebay.co.uk

 

[Erik the Awful]

this is a common fitting.

... in the US.

"I'll take things made for the US market in countries that can't use them for $500, Alex."

 

[xXxPARAGONxXx]

... in the US.

"I'll take things made for the US market in countries that can't use them for $500, Alex."

Yes, but worst case scenario, he can still order them and have them shipped from the US.

 

[xXxPARAGONxXx]

These?

10pc Steel Male Brake Pipe Union Short Fittings 1/2" x 20 UNF for 1/4" Brakes | eBay

1/2" x 20 UNF short male brake pipe fittings. Size of the male fitting - 1/2" x 20 UNF (short). Male brake pipe fittings.

www.ebay.co.uk

Looks right to me but admittedly I've never had to mess with fabbing brake lines/fittings. Wait for someone else to confirm.

 

[Pinger]

Looks right to me but admittedly I've never had to mess with fabbing brake lines/fittings. Wait for someone else to confirm.

We'll know by the end of the week if they are the correct items - or not!
I'm confident enough that you're right so ordered them. Thanks for your help - much appreciated.

 

[Pinger]

When I look here >> https://www.gmpartsgiant.com/parts-list/1999-chevrolet-suburban-c2500/brakes/brake_lines_rear.html

I find:
''
15720629
NUT, Hydraulic Brake Pipe, NUT,REAR BRAKE FRONT PIPE(PART OF 16)(1/2 X 20 X .40)''

which was assumed to be the required part (for both ends of the hard pipe/tube).

But there's also this:
''
15724652
NUT, TUBE 7/16-24X0.36,0.30THD,0.56 LONG,1/4 TUBE,STEEL,ZINC COATED CO GM6280M(REAR BRAKE REAR PIPE)''

which has a different thread size but is listed for 1/4'' pipe/tube.
The first item is apparently 'discontinued'.

 

[Pinger]

Rummaging through my stash of bolts looking for bolts for pending exhaust change I found a 1/2'' UNF (20TPI) bolt and offered it up to the female and of the flexible hose. It's too large.
Applied a bit of science (thanks Wikipedia!) and worked out that the minor diameter (across the thread peaks of the female thread) should be 9.74mm for 7/16'' UNF (20TPI) and when I measured the end of the flexible hose - accurately this time, not that 10.5mm rubbish of yesterday - it corresponds to 7/16'' So, another lot of nuts ordered. I think I've got it covered now!

 

[Pinger]

I think I've got it covered now!

Thought wrong!
Fittings arrived today and the 7/16'' - 20TPI nut wouldn't go further than two threads into the old flexible hose end. With a neighbours help, cutting open the hose thread and getting a thread gauge on it revealed it to be 24TPI. More nuts ordered....

To be fair, that is what gmautopart.com list. Whether that is appropriate for both ends of the pipe remains to be seen.

 

[Pinger]

To close this off and because someone else at some time may need to know the sizes they are...
Working from rear to front, the nut for the rear section at flexible hose, the nuts where that pipe joins the mid section and the nuts that attach the mid section to the front section are 7/16'' 24TPI. The nut that fixes the front section to the ABS unit is 1/2'' 20TPI.