Rear Disc Brakes

[87SS383]

I'm about to purchase a new rear end with disc brakes already installed. With the discs in the back I know i'm gonna have to install new brake lines, but i'm clueless as to what else i'm going to have to do. Can anyone who's installed rear discs give me some pointers so I can go into this ready & avoid any future headaches during the install?


Link to the rear end: http://www.justrearends.com/ProductDisplay.aspx?ID=7afa9cde-28f5-4410-b4a8-ffc1d2a1ff97

 

[FE3X CLONE]

You'll need a different proportioning valve. One that's setup for a disc/disc setup.

Or if you run an adjustable proportioning valve, you can take your stock valve and gut it and then reinstall.

 

[87SS383]

Thanks for the input.

 

[axisg]

you don't need new rear brake lines. Everything is the same until you come up to where the line would normally end at the wheel cylinder. On mine I made a 90deg bend, welded a clip on the housing and attached the flex line from the caliper.

 

[454muscle]

You'll need a different proportioning valve. One that's setup for a disc/disc setup.

Or if you run an adjustable proportioning valve, you can take your stock valve and gut it and then reinstall.

How necessary is the proportioning valve? I have a rear end with disc brakes installed and I got the proportioning valve, but it hasn't been installed yet. What problems would I encounter without using the proportioning valve? Sorry to hijack the thread but I figure 87ss383 could use the info as well.

 

[FE3X CLONE]

You'll end up with the rear brakes locking up before the fronts. You need to "proportion" the fluid so that you can get the brakes as equal as possible.

Remember the rear brakes are only supposed to do like 30% of the braking on the car. You have a lot less weight in the back than you do in the front and if you seen full brake pressure back there you'd have a pretty dangerous situation.

 

[uneek1976]

One other part that i changed when i did my swap was the master cylinder. I used one from a 84 caddy eldo(since the eldo had rear disk from the factory).

 

[axisg]

You'll end up with the rear brakes locking up before the fronts. You need to "proportion" the fluid so that you can get the brakes as equal as possible.

Remember the rear brakes are only supposed to do like 30% of the braking on the car. You have a lot less weight in the back than you do in the front and if you seen full brake pressure back there you'd have a pretty dangerous situation.

The calipers displace more volume than wheel cylinders thus you will have trouble locking up the rear brakes. Proportioning valve will allow more fluid to pass to the rear and allow you to fine tune the system. It would be better to run the rear disks with an adjustable valve as it will allow you to take full use of your newfound brakes but I doubt that I will personally ever get around to it ( both bolts that hold the valve are seized into the frame so it will be a real PIA )

 

[donnyR]

Do what i did b4. you can send it to flynbye.com and he can rebuild youre original one to the specs or the 4 wheel disk it cost about 30.00 or so to do or you can buy a universal one for 4 wheel disk but it wont fit in the factory mounting location. And if you redo youres you wont have to redo youre lines over to accomadate the new valve either

 

[FE3X CLONE]

The aftermarket brass proportioning valves are a direct bolt-on. The only thing I can't confirm is the electrical connection since I'm not worried about hooking it up. Just don't buy them from Inline Tube. They're about twice as high as anyone else.