Brake line tube diameter question

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moparmat2000

moparmat2000

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Need to know what the tube diameter is for a mid 70s A body disc/drum setup. Plan on plumbing and double flaring it myself.

I am using a cordoba disc setup front and cordoba drum setup in the rear, a dippy master cylinder, and a GM proportioning valve.

Thanks
Matt
 
3/16 is what im replumbing mine with. I bought mine from inlinetube.com. I got the kit it came with the copper nickle tubing the spring protective wrap and fittings for around 40 bucks. I havent installed it yet but it seems to be really nice quality.
 
This kit is awesome. Not cheap. But you will have it a life time.

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The 3/16" tube kit with 25 feet of line from inline tube w gravel guard is on sale on ebay thru motorcity muscle car for $19.95 free shipping. Was gonna get 2 kits because i need to plumb my 67 notch, and my sons 69 notch. I have an older snap on double flaring kit that works well, and a tubing line bender.
 
moparmat2000 said:
The 3/16" tube kit with 25 feet of line from inline tube w gravel guard is on sale on ebay thru motorcity muscle car for $19.95 free shipping. Was gonna get 2 kits because i need to plumb my 67 notch, and my sons 69 notch.
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That is where I got mine! Ebay store motorcity muscle. That is a good price because when i bought it the 25 foot kit was 26 not including the spring wrap. I bought it separately for around 12 bucks
 
Gonna use these type proportioning valves. My sons car is 4 wheel disc w a 8.8 xploder rear going in. I like the GM valves. I have used them with a lot of different projects. Inexpensive, works, and everywhere.

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moparmat2000 said:
Gonna use these type proportioning valves. My sons car is 4 wheel disc w a 8.8 xploder rear going in. I like the GM valves. I have used them with a lot of different projects. Inexpensive, works, and everywhere.

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Just a fair warning. I bought one of those for my sons 85 Monte Carlo and after 6 months of nothing but trouble and leaks from time to time I took the thing off and put a used factory one on from the junkyard. We have had 0 trouble for the last 6 months. I only bought the brass one because I was replacing everything and his original had the plastic fitting break off for the light wire. I would never again buy a new brass one nor recommend it. He car has new lines and cylinders and hoses calipers and master cylinder also.
 
I bought one of these aftermarket brass replacements for a 60 el camino i had that i updated with 69 chevelle disc brakes , and an S-10 master cylinder, never had a problem with it. Maybe you got a faulty one. The OEM GM ones are brass as well.
 
moparmat2000 said:
I bought one of these aftermarket brass replacements for a 60 el camino i had that i updated with 69 chevelle disc brakes , and an S-10 master cylinder, never had a problem with it. Maybe you got a faulty one. The OEM GM ones are brass as well.
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It might have been a bad one. I was just sharing my story to help people decide. The original one that I took off the car was cast and the one I picked up at the junkyard from the same G body Monte is cast. So that is one vote for ok and 1 vote for defect.
 
The factory GM ones are actually made from machined brass. I have seen cast iron ones. Those are aftermarket ones as well. Though they make machined brass aftermarket ones. Brass aftermarket is closer to OEM in construction.
 
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The hydraulic flaring tool hs great, will do amost every style under the sun.
Great for an everyday user.
I still have the double flaring kit
I got 25 years ago.
Still looking for a deal on hydraulic flaring kit.
 
My Mastercool flaring too is perfect for me. It's what the shops that make prebent lines use.
 
My stuff looks like dartfreak75 in post #6. I get the bubble for the double flare started, then with the line clamped in place, i use a small ball peen hammer to flatten it out, then i fold in the double flare with the pointed cone. I have replumbed 2 cars in the past with homemade lines using tube kits. Only had 1 leaker, had to work the seat on the flare a little more and reattach the line. That cured it.

After i bleed a system thats been opened to be repaired or assembled from a line kit, I typically will force the brake pedal down as hard as i can push it and hold it. If the pedal slowly drops as i'm holding it down under pressure w my feet then there is a leak somewhere. Time to look at every fitting in the system for fluid seepage. Most times tightening the leaking B nut a little more will correct the issue, sometimes it requires the cone seat to be worked a little more.
 
moparmat2000 said:
The factory GM ones are actually made from machined brass. I have seen cast iron ones. Those are aftermarket ones as well. Though they make machined brass aftermarket ones. Brass aftermarket is closer to OEM in construction.
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No the factory G body are cast iron. Trust me I have lived GM all of my life before coming over to Mopar because dad was Mopar. The replacement that is sold for them is Brass. I worked at the dealer when they were new also.
 
Could also be the location you live. Those cars were made in multiple factories in the U.S. and Canada. Parts for them made in many locations. All the valves i would see here including the ones on the full size pickups and S10s that had the prop valve mounted on a bracket next to the master cylinder were brass. Only time i would come across cast iron ones was early to mid 70s GM or an aftermarket valve. Now it could be a lot of people replacing bad ones out, or thinking they are bad so they replace them, but i doubt it. My brother did a mild refresh on a low mile 1987 monte SS. I need to ask him what was in his car. He bought it in N.J. so it may been built in your neck of the woods so to speak.
 
moparmat2000 said:
Could also be the location you live. Those cars were made in multiple factories in the U.S. and Canada. Parts for them made in many locations. All the valves i would see here including the ones on the full size pickups and S10s that had the prop valve mounted on a bracket next to the master cylinder were brass. Only time i would come across cast iron ones was early to mid 70s GM or an aftermarket valve. Now it could be a lot of people replacing bad ones out, or thinking they are bad so they replace them, but i doubt it. My brother did a mild refresh on a low mile 1987 monte SS. I need to ask him what was in his car. He bought it in N.J. so it may been built in your neck of the woods so to speak.
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Yea around here the ones on the frame ie: G body and other ones beside the Novas were factory cast iron as I prepped and undercoated them new and looked at them right off the factory trucks.
 
Got to be who the supplier was in your area for the assembly line. I just texted a buddy of mine who has been in and out of the dealerships as a mechanic since the 80s. He said they were brass when the cars were new, and later ones they machined em out of aluminum or some type of potmetal. We are in Texas. I think in the 80s G bodys were made in Arlington, D/FW area. Trucks are made there now.
 
moparmat2000 said:
Got to be who the supplier was in your area for the assembly line. I just texted a buddy of mine who has been in and out of the dealerships as a mechanic since the 80s. He said they were brass when the cars were new, and later ones they machined em out of aluminum or some type of potmetal. We are in Texas. I think in the 80s G bodys were made in Arlington, D/FW area. Trucks are made there now.
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It could be as I have always lived and worked near Detroit.
 
I think the GM type is a lot cleaner than the cobbled up mess that Chrysler thought up. I like mopars, but not everything they designed was stellar.

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My brothers car was a northern car. He picked it up in N.J. Said his was cast iron. My buddy has been in and out of GM dealerships as a mechanic down here in Tx. since the 80s, they were brass, then some sort of aluminum or machined pot metal after that. So it must have been different suppliers to GMs different plants at the time
 
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