Anyone replaced all the brake lines?

[rybo]

I have a 73 Mach 1 that was sitting for 30-40 years, and the brakes didn't work at all which makes sense. I replaced the master cylinder, and went through the bleeding process. The front discs were normal, easy to bleed and work fine now.

The rears I can't get to bleed, no fluid flowing and with the master cylinder cap off the fluid shoots back up through the MC. I think the proportioning valve is either stuck or rusted up. So I figured I would just replace it, but in doing so all the line connectors are rusted and I won't be able to back them off without completely stripping it off.

So then I figured maybe just cut it all out and replace the lines and PV, something I would end up doing eventually anyway, just wasn't looking to do it now. But looks like I don't have much of a choice, so my question is how much of a job is it? I've never replaced brake lines before. Are the lines just simply bolted up to the frame and relatively easy to swap out, or is there more to it that I'm missing? Just curious on any advice you have before I start ripping lines out.

I have front disc, rear drum. Thanks!

 

[MikeGriese]

There are a number of kits out there in stainless or mild steel - pick your poison. Note that the lines will come folded, so you will need to straighten them when you install them. The line to the rear runs in the torque tube tunnel and up to and across the drivers side firewall. The right front brake line runs across the firewall above the engine, so that is a bit easier to access. I installed mine when the drive train was removed, I can see where it might get tricky working around the engine, transmission and firewall accessories.

 

[rybo]

There are a number of kits out there in stainless or mild steel - pick your poison. Note that the lines will come folded, so you will need to straighten them when you install them. The line to the rear runs in the torque tube tunnel and up to the firewall. I installed mine when the drive train was removed, I can see where it might get tricky working around the engine, transmission and firewall accessories.

Ok thanks thats what I was afraid of. I was thinking of just getting straight line and making my own lines, rather than the pre-fitted, that might help me avoid the areas I can't get to. Or I just hold off on that line till I pull the engine and tranny down the road.

 

[Bentworker]

Stick with steel or NiCop The pre-bent kits are okay, but you can do a lot with a 25’ coil, some skill, a bender and a double flaring tool. The “slot machine” type flaring tools are superior to the old type.

Stainless is a pain to work with, so much so that I believe it should be avoided.




25’ roll of brake line is less than $8 from Rock Auto

 

[rybo]

Stick with steel or NiCop The pre-bent kits are okay, but you can do a lot with a 25’ coil, some skill, a bender and a double flaring tool. The “slot machine” type flaring tools are superior to the old type.

Stainless is a pain to work with, so much so that I believe it should be avoided.

View attachment 95161

Thanks, yeah I was just looking into that option, I think I'd prefer just making my own steel lines from the 25' roll and going that route.

 

[fd7]

I replaced all mine using pre-bent from InlineTube. They fit perfectly. I cant imagine bending myself and getting them to fit correctly. There's LOTS of bends, lots of 90's. They came with a nice gentle loop bend in a huge box. Were easy to straighten up for install. Just my 2 cents.

 

[dawson357]

Just did that to my 73 Grande. Got the premade SS ones from Classic Tube. The short lines were OK except the left rear was way too short. The long line from front to back was not bent correctly at all at the rear, not even close and had to clean and reuse my old one. I too had a couple of the fittings that were stuck in the PV and could only get them out when I pulled the PV and could get some torque on the fitting in a vise. Major pain getting the front to back line in with the transmission installed. Fortunately, I was swapping transmissions and did it then. The SS lines are much stiffer than the standard steel and a little harder to tweak to get them to line up. If you can rebuild your PV, would be good to keep the original. The Chinese ones are iffy and the mounting bracket is either on the wrong side or you have to attach it yourself (good luck with that). The brakes have been the bane of my journey with this car. Hopefully will drive it around the block this weekend and pray it'll stop.

 

[rcadd1ct]

I used classic tube. I went stainless.

Unsure if I would do that again as I had trouble getting them to seal at first.

They were an exact fit, though.

 

[giantpune]

I had the same issue as OP on one of my 73 mustangs. The issue turned out to be the rear rubber hose. It connects the steel line in the transmission tunnel with the steel lines on the rear axle. Mine was caked with crud. I replaced that rubber hose and the brakes worked again. I still have the long line I was going to install but didn't end up needing.

I have replaced all the lines before. If you can get the front of the car high enough off the ground, you can snake the long front-to-back line in with the drivetrain still in place. You may have to remove some small components like shock tower brace and disconnect transmission linkage.

 

[Hemikiller]

I had the same issue as OP on one of my 73 mustangs. The issue turned out to be the rear rubber hose. It connects the steel line in the transmission tunnel with the steel lines on the rear axle. Mine was caked with crud. I replaced that rubber hose and the brakes worked again.

Like GP noted, start with the body to rear axle hose before committing to a full line replacement. It's very common for the interior of the line to be blocked due to swelling of the hose.

I'd much rather use a prebent kit than making my own. Did plenty of that in my early days, the made to fit stuff is so much easier, even with the tactical planning of how to get it in the car with things in the way. I used Classic Tube for all my cars.

 

[MikeGriese]

If you think snaking prebent lines around the drive train is tricky - just wait until you try bending your own. You'll be going in and out over and over.

Buy yeah - unless you have an obvious crush in the hard lines, start looking for the blockage. Soft lines do eventually fail.