I just swapped the rear end out of my 84 z28 from disk/drums to a rear end that has disk/disk. I am not happy with the braking performance. I purchased the right proportioning valve for a disk/disk setup, but is there anything else that needs to be replaced. I have not yet installed the prop valve, I want to make sure I get everything before I start.

 

You'll have to change the brake lines on the axle itself. The drums have a single flex line going from the body to the axle then hard line going into both drums. The calipers need flex line going into them as well.

 

Make sure that the combination valve you purchased 'looks' exactly like the one in your car--if not, you may have an SAE vs. metric problem where the lines are concerned. I assume the new rear is an 82-88 with Delco-Moraine iron calipers. If it's an 89+ with PBR's, you'll need the 1LE combination valve. Either way, you'll need parking brake cables, and if the new rear has a different gear ratio, you'll need to swap the drive and/or driven gears to make the speedo function correctly.

The following link, toward the bottom, may answer your questions more fully:

https://www.thirdgen.org/forums/tran...-10-bolts.html

JamesC

 

Thanks for the link. I wasn't sure if I needed a new master cylinder as well, but the link answered it. I guess it wouldn't hurt to change out a 25+ year old master cylinder anyways.

 

i thought i heard somewhere the master cylinder needed to be swapped. is this true?

so far i got:

brake lines
ebrake cables
prop valve
(i plan on keeping the same gear ratio)

 

No. The following from the 10-Bolt FAQ I listed above:


If I Swap From a Drum to a Disc Rear End Do I Have to Change the Master Cylinder?
No. https://www.thirdgen.org/forums/brak...fferences.html (Master Cylinder Differences)

JamesC

 

he would be right on an older camaro but these ones i believe you just have to change the porportioning valve to make it work, i got mine out of a car and grabbed everything i could but the portportionging valve