84-85 GSL rear-end into 84 GS...
 

I'm going to start this tomorrow... Is there anything specific I need to switch? From what I've seen of my new rear end compared to the one already on the car, the mounting hardware looks the same... The e-brake cable attachments look the same... So, I'm figuring if there are any sort of differences, it will be between the drums and discs... The guy put in the little splitter for the brakes when I bought it, but it looks identical to what's on it now... I bought a master cylinder on Ebay for a GSL in case I need to swap that out, but it seems identical as well... I have new shocks and RB springs, the only thing I don't have that I want is all new bushings... For now, I plan to get the old rear end off and the new one cleaned up/painted and ready to go.

What am I missing that I'm going to need?

Brake proportining valve.

The ebrake cables are not (wasn't on mine) the same. I had to lay in mud pit and pull them off a car in the junk yard. VB also has diff. part numbers.

I think I might have that... What does it look like?

This is the one I won:

http://cgi.ebay.com/ebaymotors/ws/eB...3AAAQ%3AUS%3A1

All you will need are the right and left disc brake cables. I did the same swap, but kept the drum proportioning vavle. I don't know if there is much difference or not. You could take them both apart and compare the piston and spring inside, along with the part number cast in the body.

You sure it doesn't have that stuff already? It doesn't seem to have any empty holes or anything.

The prop valve sits next to the master cyilinder. (Or maybe it's on the firewall... I havent been under a 1st gen hood in a while. Follow the lines. It's the device that splits between front and rear.

The deal is that drum brakes have return springs. Discs do not... The proportioning valve for drum brakes will leave residual pressure in the system just under the pressure needed to overcome the springs... This allows the drum brakes to act quicker. As soon as you hit the pedal, the shoes begin to move... If this part of the valve was not there, the pressure would have to build up before the shoes moved.

If this valve is left in, the rear brakes may drag ever so slightly until they wear off...

Essentially, it'll cause you to go through rear brakes a bit quicker than usual.

The brake porportioning valve is part of the brake master cylinder assembly-system. It won't be on the rear axle hardware. It does appear that you have the emergency brake cables, there, though.

The guy included that little valve.

That part about residual pressure left in the system just doesn't sound right Pele. Are you sure of that? It was my impression that the block is just a splitter. And to retain pressure in only the lines that go to the rear brakes you would need some kind of check valve, right? I'm just not seeing it, but if you'll explain it to me I'm always a willing student... :)

Pele is correct, You can fix it though by removing the little ball type check valve thing.

So, where is the little check-valve within the brake piping? I have yet to do my swap.

on a scale of 1-10 how hard is this i have an 85 gsl parts car that i'm gonna swap the rearend out of and put in my 84 gs i'm no real mechanic but i wanna do it myself. Is it hard or do i just need to have all the parts and a little know how?

Fred

It's right by the master cylinder under the hood.