86Z

iTrader: (4)

i have a copy of camaro performers and they did a baer brake upgrade all the way around on it, and they took the spring and plunger out of the combo valve and put the valve back in and then installed an adjustable valve to the rear lines, how is this different then the mod talked about on here with making a plug for the combo valve?

MurcoRS

I didn't see the article but from what you are describing It sounds like they just bypassed the combo's prop-valve to keep the pressure differential switch functional. Blocking-off and capping the rear of the combo valve (the prop-valve) would eliminate a worthwhile safety feature.

86Z

iTrader: (4)

right exactly what i dont want to do, is that what happens when you install a baer brake upgrade? how would i run a wilwood adjustable for the rears with a combo valve?

trumps2000

iTrader: (2)

I'm planning on doing this to my Z28. Pulling the spring and plunger totally eliminates the proportioning action of the combo valve giving full pressure to the rears. Then on the tube exiting the combo in the front (rear lines) just below the combo valve install an adjustable prop valve. I think this is the cleanest way to add one, rather then replacing the combo valve with a dozen adapters and tubes.

I haven't been able to finish this mod yet. I replaced my rear lines with stainless steel and later found out that S/S is an SOB to cut and flare! I have the adj. prop valve and no way to install it. I guess I'll wait and have someone with the proper tools do it for me. I haven't gotten it on the road quite yet, but I will say I'm already impressed with the combo valve mod. Most poeple have problems with the rear discs doing nothing even in the air, but when I bled the brakes I defenitely saw the caliper clamping the rotor.

MurcoRS

Unless you are running something signifigantly different than a 1LE brake set-up (12-13" rotors, dual-piston calipers in front, single piston '89 or newer rear calipers) stick with a factory 1LE combo valve.
If you insist on running an adjustable prop valve that is the way to do it (removing the OEM plunger and spring in the combo valve, then running it downstream).
I am the biggest opponent on this board to running adjustable prop valves on street cars. The reason is that the car you drive on the street has varying rear loads based on number of passengers, different stereo set-ups, luggage or other junk in the trunk, how much gas in the tank, etc... If you install one you must set it up making sure that the rear is as lightly loaded as possible (no stereo equipment, 1/8 tank of gas, clean brake fluid) and adjust it until the rear engage full lock JUST BEFORE the fronts. Once you load the stereo, gas, and other stuff in you shouldn't run into premature rear lock-up do to load lightening.

86Z

iTrader: (4)

i'd love to install just the 1le valve, i'm just looking for my options, i'm in the process of installing 98+ 12" rear disc brakes, i'm going to be installing the 98+ ls1 dual piston calipers in the front, your saying the 1le valve will work okay with ls1 brakes all the way around?

MurcoRS

I'm running C5 calipers with 12" rotors in front and '89 PBR calipers in the rear with 12" rotors. I'm using a 1LE combo valve and it works perfectly.

86Z

iTrader: (4)

cool, thanks alot i'll give it a try.