Rear Brake Lines

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79ramp

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Everett, WA
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Aaron
Truck Year
1979
Truck Model
C30
Engine Size
454
I think I know the answer to this one but figuring it can't hurt to get other opinions: is there any reason for the two unions in the front-to-rear brake line other than ease of installation/fabrication? One of mine is leaking, I suspect due to a bad flare on the SS line. My '79 is a cab and chassis model (159" WB) so I ended up ordering a crew cab (164" WB) kit and modifying by cutting and have someone re-flare one end of the rear-most tube.

I am debating on either bending a plain steel line to replace the leaking one or making a line to run the full length (or to eliminate at least one of the unions...less chances for leaks). In all honesty, it will probably depend mostly upon my level of motivation this weekend but it got me curious if there is a reason for keeping the unions.
 

Frankenchevy

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I think I know the answer to this one but figuring it can't hurt to get other opinions: is there any reason for the two unions in the front-to-rear brake line other than ease of installation/fabrication? One of mine is leaking, I suspect due to a bad flare on the SS line. My '79 is a cab and chassis model (159" WB) so I ended up ordering a crew cab (164" WB) kit and modifying by cutting and have someone re-flare one end of the rear-most tube.

I am debating on either bending a plain steel line to replace the leaking one or making a line to run the full length (or to eliminate at least one of the unions...less chances for leaks). In all honesty, it will probably depend mostly upon my level of motivation this weekend but it got me curious if there is a reason for keeping the unions.
I think it was ease of installation, but I’m not certain. Your 2wd routing may be easier, but honestly going from the brake proportioning valve all the way to the load sensing valve in one piece is tough. I had two frame braces and a shackle to contend with. I could have done it but I don’t think it would look as nice.

I like my straight lines to look straight and my radii to look constant. If you aren’t as ocd as myself, it can be done no problem. Especially if you use nicopp. It is SO easy to bend. You can carefully bend it by hand where most tube benders won’t fit.

If you buy a coil of line you can get it perfect after hand straightening it by clamping one end in a bench vice and the other in some vice grips. Then you hold the vice grips at a 90 degree angle to the line and hit the vice grips with a hammer. This straightens the line like an arrow.
 

79ramp

Full Access Member
Joined
May 28, 2017
Posts
53
Reaction score
25
Location
Everett, WA
First Name
Aaron
Truck Year
1979
Truck Model
C30
Engine Size
454
I think it was ease of installation, but I’m not certain. Your 2wd routing may be easier, but honestly going from the brake proportioning valve all the way to the load sensing valve in one piece is tough. I had two frame braces and a shackle to contend with. I could have done it but I don’t think it would look as nice.

I like my straight lines to look straight and my radii to look constant. If you aren’t as ocd as myself, it can be done no problem. Especially if you use nicopp. It is SO easy to bend. You can carefully bend it by hand where most tube benders won’t fit.

If you buy a coil of line you can get it perfect after hand straightening it by clamping one end in a bench vice and the other in some vice grips. Then you hold the vice grips at a 90 degree angle to the line and hit the vice grips with a hammer. This straightens the line like an arrow.

I don't think I even have a load sensing valve on mine, IIRC. Either way though, that would definitely be a lot of twists and turns to try and navigate with a 15'-long brake line lol. Knowing myself the way I do, I will probably be lazy and bend the line from the last union to the rear axle and call it good until something else leaks.

That is a great idea for straightening, I never would have thought of that but I bet it works great! I'll have to give it a try.
 

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