Another Brake Line Question

I’ve been working on a frame off restoration/Modification on our 1971 Jeep CJ5. One of the modifications has been exchanging the model 27 axle with a disk disk brake model 30.

I’m at the point where I will be replacing all the brake lines. Im not able to get to the location where the Jeep is stored, but would like to begin ordering parts. I’ve got a few questions, that im hoping you guys can help me with:

1. What size brake line to order? 3/16 sounds is about what I remember, but I’m not sure.
2. Stainless Steel Vs Steel?
3. Where to source a new Master Cylinder?
4. Residual valving- since the d30 will have disk brake?
5. Is it necessary to replace the proportion valve?

One huge mistake I made when I disassembled the Jeep last summer, was not taking enough photos of brake system, routing, etc.

Any help or suggestions will be GREATLY APPRECIATED.

Thanks

 

You might consider buying a roll of 3/16 Cunifer or NiCopp, a bag of fittings, and a double flaring tool.

I find making my own brake lines is a great convenience. The copper-steel lines are easier to work and resist corrosion.

 

As I remember the rear line goes inside the left frame rail lower flange, there is mouse holes to run the line through the braces. It turns out to the middle of the crossmember above the axel center, where it connects to the frame, then the hose to the rear axel. The front goes in the lower left rail to a four way connector by left front brake, then on across the rear of the front crossmember to the right side frame to another connector for the other hose. You might have to get new frame clips to attach your lines to the frame flanges. Good Luck.

 

Thanks, I hadn’t thought about the copper. And thanks for the routing advice

 

Buy enough extra line to practice flaring the ends. After the first couple of times you'll have it down. It's not that hard to do and you can put the lines right where you want them.

Mike

 

It's not copper, it's a steel alloy with copper in it. Copper-Nickel-Iron. Don't use copper tubing; that would be dangerous. Copper will work-harden under even minor vibration and break, if it first does not burst from the pressure.

The Cunifer/Nicopp tubing is great, and cheap on eBay. Last I bought was a 25' roll for about $25.

 

Thanks for the clarification. Does anyone have a recommendation on where to source a master cylinder?

 

I used all MBM brake components on mine when I converted from the single circuit drums to 4 wheel power discs. The brakes work very well.
PBUJ7486D - 1974-1986 Jeep CJ Power Brake Booster Conversion Kit

PV2K-2 - GM Left Side Prop Valve Kit. Disc/Drum - Brass 1

Mike

 

I’m looking for the frame mounted version like the original, but hopefully one that works well with the new disk brakes.

 

Awesome, thanks for the help

 

Does anyone know of a drawing or diagram that shows the OEM routing for brake lines other than the ones in the FSM? It's hard to read the pictures in there and wondering if anyone has an overhead view picture from a frame off restoration or anything like that? I'm getting ready to run mine and I can't find the OEM lines in my bone pile.

 

Inline Tube sells a pre-bent set for early CJ5s. I can't speak to whether they are a perfect match to stock or not. I did use some of their components when I put my system together and they worked well. They have both stainless and regular steel lines.

1955-66 Jeep CJ-5 Manual Drum Complete Brake Line Kit 8pc, Stainless

Mike

 

Ya know, stainless won't rust, and is really strong. But for the price of their kit you can buy Nicopp tubing, a bender and an excellent flaring tool. I have the Mastercool flaring tool ... pricey but makes a perfect flare every time. The Eastwood flaring tool gets good reviews too. Do it yourself and you'll own the tools. (Looks like a relabeled TGR https://www.amazon.com/TGR-Professional-Brake-Flaring-Degree/dp/B01HOXH242/ref=sr_1_12 ) I recommend the Robinaire bending tool, though if you use Nicopp tubing, you can bend by hand over a form. Stainless is hard to work with, if you choose to do it yourself. Get some stiff wire and bend it to the form you need, then copy that with your tubing.

 

I'm going to do this myself because I want to learn how to do it, and I have a mechanic buddy who is going to each me and who has the tools.

Regarding a kit, I have front disc brake conversion and rear 11" drums from Herm so I need to bend the lines, I don't think a pre-formed kit would bolt up. Good news though is that I found the old lines under a pile of pine needles outside so we at least have something to roughly follow.

 

You can buy the spiral stone guard from Summit and other places. This will give your lines a finished appearance, and actually does protect the tubing. Be sure to put it on before you finish the ends!

https://www.amazon.com/dp/B01IRQXDZC/ref=sspa_dk_detail_2

 

Do tell! You got any pictures??

 

I'm sure this is true.

But my success rate with a cheap hand tool went way up when I paid careful attention to pre-chamfering the ID as well as the OD.