Brake Tube/Fitting sizes?

[erasedhammer]

I tried looking up some part numbers for the inverted flare fittings in the brake system, but I cannot find any details about the thread spec or nut size, if the part number even exists.
And the few posts on here I hear reference to 3/16 and 1/4" tube sizes. But the part #s won't tell me...

Can anyone help with tracking down the tube size and nut size?
All of these, I couldnt even find the part number online or the result showed nothing about the size.

Master Cylinder Front Res to Proportioning Valve

-Tube #603827 - Unk Diameter​

-Nuts #137397/#9424955 - Unk size (Are these two different nuts on the same line??)​

Master Cylinder Rear Res to Proportioning Valve

-Tube #3696822 - Unk Diameter​

-Nut #15607227 - Unk Size​

Proportioning valve to each front caliper (excluding flex hose)

-Tube #3696822 - Unk Diameter​

-Nut #9432075 - Unk Size​

Proportioning Valve to Rear (Frame Junction)

-Tube #603827 - Unk Diameter​

-Nut #9424955/#137397 - Unk Size (Again, why the two part #s?)​

Frame Junction to Rear Brake weight proportioning valve

-Tube #603827 - Unk Diameter​

-Nut #9432075 - Unk Size​

Theres also the small part that jumps between the weight proportioning valve and the flex hose, part #14036792, which is sold out/discontinued everywhere and the TM doesn't have a raw tube part number to make it out of (apparently it was only sold as a pre bent unit?). Best part of that is I just had that line blow open on the road. The rust is real.

Again, the part numbers are not showing specs on the sites I've been checking. I'm trying to have some custom lines made up, and I can measure the length by hand, but tube and nut sizes I need before ordering.

And just to clarify, these flares are the inverted double flare style?

 

[cucvrus]

I think I have a small brake tube for the rear anti lock rear brake system on the CUCV trucks and cab chassis models. Brand new GM. I have made a few. The one side is a metric flare nut and the other is standard. I have a few of the height sensor valves and linkage also. But just for the record you can bend tubing flare it and install. Let me know if I can assist.

 

[erasedhammer]

I think I have a small brake tube for the rear anti lock rear brake system on the CUCV trucks and cab chassis models. Brand new GM. I have made a few. The one side is a metric flare nut and the other is standard. I have a few of the height sensor valves and linkage also. But just for the record you can bend tubing flare it and install. Let me know if I can assist.

Thanks for the offer, but I want to make my own lines from stainless steel to avoid the rusting issue in the future.

I'm mainly looking for part numbers to specific specs (thread size, count, hex size, tube diameter) so I can identify which sections use what and not waste time or money ordering supplies.

 

[reloader64]

LMC Truck offers pre-bent stainless steel brake lines. Cost is $200-250, I think.

Scott

 

[porkysplace]

I think I have a small brake tube for the rear anti lock rear brake system on the CUCV trucks and cab chassis models. Brand new GM. I have made a few. The one side is a metric flare nut and the other is standard. I have a few of the height sensor valves and linkage also. But just for the record you can bend tubing flare it and install. Let me know if I can assist.

You can get fittings to go from metric to standard threads and use pre-made lines ( still have to bend them ) , Myself I by rolls of tubing and make my own.

 

[erasedhammer]

LMC Truck offers pre-bent stainless steel brake lines. Cost is $200-250, I think.

Scott

That kit looks very enticing. I am concerned that I have a dually K30, and their kits only go up to K20 (1/2 ton). I'd hope the brake lines are rated for the higher gvwr.
It looks like #34-5633 (Brake Line Kit-8pc-Pwr Longbed 4 Wheel Drive 1/2 Ton 81-87) is the one that might fit a CUCV.

 

[Guyfang]

-Nut #137397

	THREAD CLASS	2A
	THREAD DIRECTION	RIGHT-HAND
	FABRICATION METHOD	BAR STOCK, MACHINED OR FORGED
	CASEHARDENING INDICATOR	NOT CASEHARDENED
	OVERALL LENGTH	0.594 INCHES NOMINAL
	THREAD SIZE	7/16-24
	TUBE OUTSIDE DIAMETER FOR WHICH DESIGNED	0.250 INCHES NOMINAL
	III END ITEM IDENTIFICATION	GRUMMAN A10 AIRCRAFT
	SEAT ANGLE IN DEG	45.0
	SCREW THREAD SERIES DESIGNATOR	UNS
	WIDTH ACROSS FLATS	0.438 INCHES NOMINAL
	SMALLEST INSIDE DIAMETER	0.255 INCHES MINIMUM AND 0.258 INCHES MAXIMUM
	MATERIAL	STEEL
	PROPRIETARY CHARACTERISTICS	PACS
	STYLE DESIGNATOR	INVERTED NUT, TUBE, FLARE
	SPECIFICATION/STANDARD DATA	81343-J512 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD
	NONDEFINITIVE SPEC/STD DATA	9 FIGURE

9424955

	THREAD class	2A
	THREAD DIRECTION	RIGHT-HAND
	FABRICATION METHOD	ANY ACCEPTABLE
	CASEHARDENING INDICATOR	NOT CASEHARDENED
	OVERALL LENGTH	0.620 INCHES NOMINAL
	THREAD SIZE	9/16-18
	TUBE OUTSIDE DIAMETER FOR WHICH DESIGNED	0.250 INCHES NOMINAL
	SEAT ANGLE IN DEG	45.0
	SCREW THREAD SERIES DESIGNATOR	UNF
	WIDTH ACROSS FLATS	0.557 INCHES MINIMUM AND 0.562 INCHES MAXIMUM
	SMALLEST INSIDE DIAMETER	0.257 INCHES MINIMUM AND 0.262 INCHES MAXIMUM
	SPECIAL FEATURES	BLUE HUE FINISH FOR IDENTIFICATION
	MATERIAL	STEEL
	SURFACE TREATMENT	CHROMATE ZINC
	STYLE DESIGNATOR	INVERTED NUT, TUBE, FLARE

Tube #3696822 4710-00-395-5144
Nut #15607227 5310-00-380-1514
Tube #603827

part #14036792

	WALL THICKNESS	0.035 INCHES NOMINAL
	THREAD CLASS	2A FIRST END
	THREAD CLASS	2A SECOND END
	THREAD DIRECTION	RIGHT-HAND FIRST END
	THREAD DIRECTION	RIGHT-HAND SECOND END
	MATING END QUANTIy	1 SECOND END
	MATING END QUANTITY	1 FIRST END
	TUBING MATERIAL	STEEL
	END CONNECTION STYLE	SWIVEL NUT, INVERTED FLARE FIRST END
	END CONNECTION STYLE	SWIVEL NUT, INVERTED FLARE SECOND END
	DESIGN FORM	PREBENT
	TUBE OUTSIDE DIAMETER	0.250 INCHES NOMINAL
	NOMINAL THREAD SIZE	0.438 INCHES FIRST END
	NOMINAL THREAD SIZE	0.500 INCHES SECOND END
	MATERIAL	STEEL SINGLE END
	THREAD SERIES DESIGNATOR	UNS FIRST END
	THREAD SERIES DESIGNATOR	UNS SECOND END

 

[ehuppert]

I buy rolls of nicopp and make my own. Will outlast the rest of the truck..... Like making my own so I can secure neatly. The nicopp bends easily by hand, much nicer to work with than stainless. The particular product I use comes with a bag of fittings.

Unfortunately I'm in the rustbelt, have some experience replacing brake and fuel lines! And also other assorted under vehicle metal pieces.....

 

[Keith_J]

Copper nickel alloy gets my approval too. Stainless requires premium tooling to properly form the double flare. Copper nickel is easier than steel to form.

 

[cucvrus]

I never seen the point of using stainless steel parts on a steel frame and body. Exhaust is even going a bit far. But it ain't my vehicle. I had an M1009 that had a complete SS exhaust system, and it was great, but it was on it when I bought it. It never wore out as long as I had it.

 

[porkysplace]

I never seen the point of using stainless steel parts on a steel frame and body. Exhaust is even going a bit far. But it ain't my vehicle. I had an M1009 that had a complete SS exhaust system, and it was great, but it was on it when I bought it. It never wore out as long as I had it.

Since frames are 10x or more thicker than exhaust , it makes sense using stainless in states that dump salt like there is a never ending supply ,
or replace it every year or two .

 

[cucvrus]

Copper nickel alloy gets my approval too.
I have used this stuff on salt spreader trucks that the frames rusted thru and the copper nickel brake line were still in place. They were exposed for 10 + years. Go figure. The frames on a CUCV pick up like to rust thru right at the front and rear axle spring hangers. The shackles go first and then the mounts. I replaced many of them. I have stock in CUCV frame mounts I removed over the years. Oil pans rusting thru, motor mount supports. I seen and replaced them all up here in the semi salty area I live in. The further north you go the worse it gets. I mean these trucks are quickly approaching their 40th anniversary. Everyday another CUCV bites the dust. Rust never sleeps. It may be slowed but never stopped. Have a Great Day and stay warm. It was snowing here yesterday. No Salt required.

 

[erasedhammer]

Copper nickel alloy gets my approval too.
I have used this stuff on salt spreader trucks that the frames rusted thru and the copper nickel brake line were still in place. They were exposed for 10 + years. Go figure. The frames on a CUCV pick up like to rust thru right at the front and rear axle spring hangers. The shackles go first and then the mounts. I replaced many of them. I have stock in CUCV frame mounts I removed over the years. Oil pans rusting thru, motor mount supports. I seen and replaced them all up here in the semi salty area I live in. The further north you go the worse it gets. I mean these trucks are quickly approaching their 40th anniversary. Everyday another CUCV bites the dust. Rust never sleeps. It may be slowed but never stopped. Have a Great Day and stay warm. It was snowing here yesterday. No Salt required.

I wonder what the market is like for frame assemblies. My frame is pretty much covered in rust, yet to see any perforations though (other than brackets).
I hope to soon pull the body and drivetrain out and do a hot dip galvanization, might be easier with a less rusty frame and just do a swap when the time comes.

 

[cucvrus]

I had multiple CUCV pick up frames a few years back. Now I am down to one nice, clean, straight M1009 frame that I am going to have blasted and painted. I am going to keep it and stock it for sale when someone needs a nice clean M1009 frame. They are not making these parts anymore and I wish I would have had better hindsight as I scrapped many valuable CUCV parts, frames over the last 27 years. Good Luck in your search. I think the Hillbilly Wizard may have a few CUCV truck frames. Nice frames are hard to come by. All frames are NOT created equal.

 

[erasedhammer]

A quick follow-up to the LMC truck stainless kit. I decided to go with it because it was an easy option for long lasting brake lines.
One big caveat, they do not sell a kit for K30's and so, the rear lines going into the load sensing brake valve do not fit at all. I also ran into issues with the rear axle lines not fitting at all, but thats mostly due to my truck being a dually with the D70HD. I managed to get those lines in fine, but they didn't quite match up to the contours of the original.

I don't haul anything heavy, so if the K20 trucks don't need that valve, then I don't need it either.

 

[Russm]

Another up for the copper-nickel brake line. I redid my entire brake system a year or so ago. Got a an inverted flare former, a bag of fittings. Everything was fairly standard and easy.

Just don't forget to put the fittings on the brake line before forming the flare

Sent from my LM-V600 using Tapatalk

 

[Guyfang]

I am an electrician. After you have repaired 20-30 electrical extension cords, before lunch, sometimes I would find my self looking at a cord, that had to of the same plugs on it. Feels pretty stupid.