So I already read a sticky thread on this here but I'm not quite getting the brake line mods required and am wondering if someone can clarify.
I have a 1991 z with drums. I'm putting in a 2000 TA rear with discs. I got a 4 disc brake proportioning valve, a 4th gen master cylinder, and a complete rear brake set off a 1999 z28. My question is what do I need to do with the brake lines. Do I leave the main line the way it is all the way from the proportioning valve back to the existing tee on my third gen rear end then screw the fourth gen lines into that tee? Or do I need to do something else? Any help will be appreciated

 

its a bolt in deal. just remove the old rear, install the new rear with its existing lines in place and hook it back to you stock flex line right before the axle, or better yet, replace the flex lines while your at it. thread sizes are the same AFAIK

 

Cool thanks. I'll post the results

 

Only a bolt-in if the rear came from a car that didn't have 4-channel ABS.

If it had that, then there used to be individual brake lines from the ABS pump all the way back to each rear wheel, instead of one line that served both. A rear set up for 3-ch ABS would work though.

But if it had 4-ch, you'll need to do some brake line plumbing on the rear. Best bet there might be to take the center tee fitting off the drum rear and mount it to the other; go to the store and get some "bubble" flare lines of appropriate lengths; and an Earl's brake line kit for a 4th gen with 3-ch ABS.

 

Ah here comes the confusion. The rear had abs my camaro with the drums does not. Single line back to the tee at the existing rear end. So I cannot(or should not) screw the brake lines from the fourth gen calipers into the third gen tee? The fourth gen brake set I got off eBay seems to be for the dual line set up. Would you happen to have any pics or can you direct me to some of the 4th gen 4 and 3ch abs? Sorry I'm a brake line novice. (ps I will not be using any abs as my car is not equipped with it)

 

Of course; no 3rd gen had ABS of any kind. ABS in and of itself isn't the issue here. What's of concern, is how the system is plumbed.

THINK. If your car was to have 4 ch ABS, that means, each individual wheel's speed is measured by a sensor, and each individual wheel's brake is controlled by the pump.

THINK!!! What would the wiring look like in that system? What would the plumbing look like? THINK!!!!!!!

Now consider "3-ch" ABS. In that system, each front wheel has separate sensor and fluid, but the rears share a sensor and fluid. THINK!!!! what would the wiring in that system look like? How would it be plumbed? THINK!!!!!!!!! Stop reading until you have THOUGHT all the way through what that distinction means to the system hydraulics.

Doesn't matter whether your car has ABS or not; what matters is, WHAT DOES THE PLUMBING LOOK LIKE. THINK!!!!!!!!

If the rear you have has individual lines going to each wheel, it's 4-ch. THINK about what that means!!!!!!! You'll have to change it.

If your rear had 3-ch ABS, then the rears share a fluid feed, and its existing plumbing will hook to your car, but you just won't have that pump doing the ABS thing to you (making sure that the maximum amount of braking you ever have is whatever the minimum amount any wheel provides).

Did I mention, you should THINK about how a system that dynamically adjusts the braking of individual wheels in real time to make sure that none of them locks up, would need to have its plumbing arranged? If not, THINK about it. Use your brain. You've obviously got one, (unlike me) since you're asking the right questions at the right place (here), so put it to use. THINK!!!!!!!!!

 

I Am Thinking about it as I'm unclear how the fourth gen braking system is set up as it compares to my third gen and how I'm going to marry it in nore am I sure how the abs in a fourth gen works hence my search for clarification here. Guess I'll figure it out this weekend

 

There are 2 ABS systems in 4th gens; 3-ch, and 4-ch. Not sure what years models which got which but it's REAL EASY to tell the difference; all you gotta do, is look at the plumbing.

Start with the basics of brakes. We all know what they're for and what they do. One thing that might not be obvious unless you THINK about it for a minute though, is that it's easier for something to KEEP sliding once it's started sliding, than it is to start it sliding. THINK about that for a minute: it's why a car swaps ends if the BACK brakes lock up but the FRONT ones don't; the back, under those conditions, has less force trying to slow it down, than the front, and therefore the BACK tries to outrun the FRONT. Not good. You back into the guardrail.

So, for the highest possible brake effectiveness, you want the wheels NOT to lock up.

What ABS is, is a system that monitors the speed at which each wheel is turning at, and if you're pressing the brakes and one of them is turning ALOT less than the others, (we call that condition "brakes locked up"), it reduces the braking effort to that wheel.

In order for something ("pump") to alter the braking effort to individual wheels, there has to be a hydraulic connection ("line") to each wheel.

If you THINK about how a car with a setup like this would have to be plumbed, it should be easy to figure out that there would be a line going from the "pump" ("module", "controller", whatever....) to EACH wheel. One wheel, one line. 4 wheels, 4 lines. We call this a "4-channel" system because it has 4 sensors, 4 valves, 4 lines, and the ability to vary each of the 4 independently of the other 3.

OTOH, if you get up under your car, you will see that it is NOT plumbed like this; there are only 3 lines. Left front, right front, and both rears. Clearly if you took a rear end that has a line going to each individual wheel ("4-channel"), you would see that there IS NOT a line going to the center of the rear and splitting off to both wheels in common.

Some 4th gen cars had what we call a "3-channel" ABS; instead of being able to vary all 4 wheels independently, it can vary each front independently, but the rears are joined together. There is one line going to the center of the rear and splitting off to both wheels in common.

Mostly earlier ones had the 3-ch system, and mostly later ones had the 4-ch. The mere fact that it's a "4th gen rear end" doesn't tell you which kind it has. You gotta LOOK and THINK.

Shouldn't be too hard to figure out, ifyou have a rear that came out of a car with 3-ch ABS, the plumbing is compatible with yours. Life is good.

But if you have a rear set up for the 4-ch system, it WON'T have the center splitter block and the lines going from there to each wheel. Therefore if the rear you have is that type, you'll have to do some plumbing.

See, not too hard to figure out, eh??

 

Although I'm not to sure you are speaking to me in such a condescending manner I do appreciate that you have taken the time to clarify the workings and differences in the rear ends. The second answer helped a lot The rear end I have has no break lines attached so I had no idea if it was a 3 or a 4 channel. The stuff I bought fo it is definitely a 4 channel so I will modify as needed thanks

 

I have found a 2002 camaro rear with discs, it is a 10 bolt but how can I tell if it is from a v8 car or a 6? I'm hoping it is a zexel torsen but it is sitting on a rack in such a way I can't rotate the pinion.

 

Drop the cover?

JamesC