Manual disc problems

[ks71z28]

Ok I ditched the dual diaphram booster for a 1" bore master. I have stock calipers front, and rear WS6 T/A discs. The peddle is bouncy and takes a lot of effort to even slow the car. I bled and checked several times. I have NEVER driven a manual disc car, only drum. My Firebird booster is bad and it takes less effort to stop that car, with the booster disconected. Any thoughts. Am I expecting too much , but i thought peddle would at least be firm. I amy try another master to see if that is the issue, cheap part store rebuild!
Keith

[67bird]

First things first, did you move the clevis to the right hole in the pedal?, Secondly is the master you are using the original type for the car (ie. a power brake master)? These sound like dumb questions but the more info you give the better answer you may get.

[6'9"Witha69]

Smaller bore master (7/8 or 15/16) will make a difference. The correct clevis placement is also imperative. Changing the rear line from 1/4 to 3/16 will make a differnce as well.

[Skip Fix]

"with the booster disconected" I assume you took the booster completely off and not just disconnected the vacuum. I got a rebuilt booster for a car at OReilly's for fairly cheap.

Which pedal were you using with the TA booster? The 4 wheel disc pedal has the hole even lower than the regular power booster pedal giving less leverage as the dual diphragm makes it up. Move the pivot up to the brake light bracket hole already there see what that gets you.

The factory felt a 1 1/8 master was needed for all power brakes in TAs and Camaros 78 and up that I have worked on, 2 wheel and 4 wheel disc. But smaller will increase pedal feel.

[ks71z28]

Yeah more info was probably needed. I have complete WS6 set up with dual diaphram booster, and adjustable prop valve. I removed booster and WS6 master, Installed 1" Covette 68-7??? manual master cylinder, put pushrod in upper hole where brake light switch used to be mounted. Peddle never feels hard, gets firm but not hard. I have blead several times. i think master may be problem, BTW the rear line from master to prop vlave is 3/16" not 1/4" i changed it. Any suggestions

[6'9"Witha69]

I meant the rear line from the distblock to the rear drop.

[JoeG]

I'm having the exact same issue with my 32 ford.
1" Corvette style master cyl
GM Metric front Calipers
89 Explorer Rear Calipers
5:1 Peddle Ratio
Wilwood Bias Unit on Rear line
2 lb Residual Valve (one for fronts and 1 for rears)

I'm going to change out the pads for Hawk HBS compound since I don't know what compound came with the kits

Another though is installing a residual valve per wheel instead of one front and one back.

Considering installing ECI pressure multipliers front and rear, but I can't seem to find anyone who's had experience with them.

If I find a solution, I'll post it and hope you'll do the same.

[ks71z28]

OK, I traced it down to likely a bad master. I put a different one on and fimer peddle.

KS