Hello all,

I completed the LS1 front swap many months ago and now I am looking at putting a 4th gen rear in my car. I have been doing a lot of reading about adding aftermarket proportioning valves, swapping springs in the factory ones and other mods.

My question is doesn't it just make sense to run an LS1 master, booster, and distribution block if you have the LS1 calipers on all four corners? Can the ABS be separated from this assembly?


Thanks to all of you who make this forum what it is.

 

You can run a LS1 master/booster or even a LT1 master/booster but the LT1 master will require a line adapter if you don't plan to mod one of your existing 3rdgen lines... Most 4thgens that do ABS delete will actually run a 3rdgen proportioning valve, the only down side is it is not "factory" adjustable and most people that do, do this will run an adjustable proportioning valve... I currently have a LS1 master cylinder and LT1 brake booster with a disc/disc 3rdgen proportioning valve, ls1 front calipers / lt1 rear calipers

there is a thread already floating around on the top of this section that i had previously posted in just to make it easier here is the link

https://www.thirdgen.org/forums/brak...r-mc-help.html

 

Interesting the 4th gen guys are using the 3rd gen proportioning valves.

So, I guess the plan of attack is to pick up an LS1 booster and master, which will give me a little more room and allow for larger caster adjustment
Then I'll try the different spring trick and if I'm not happy hang an adjustable proportioning valve on it.

Correct me if I'm wrong but swapping the spring basically takes a disc/drum prop valve and makes it a disc/disc prop?

 

Check out:
https://www.thirdgen.org/forums/brak...e-upgrade.html

Swaping in diffrent springs will not make a disc/drum to a disc/disc or vice versa, There is an internal metering valve or "hold off valve" in the combination block, The metering valve will not allow the pressure to rise at the front discs until the pressure at the rear drums has risen sufficiently to overcome for the brake shoe springs. The proportioning valve regulates the amount of pressure to the rear brakes. When proportioning a disc/drum setup when there is pressure applied, the full pressure is only allowed to the rear drums up to a certain point, beyond that point the pressure to the rear is reduced preventing rear wheel lock up.