hookdup

Have a new to me 1998Trans AM,
(ex-motorola Gt, AIX, ITE)( now strictly HPDE)
trying to sort out,
Car is equipped with Wilwood 6SLR front, new rotors and hats, and stock rears.
Brake pedal is extremely low upon first press, I am sure part is related to pad knockback, so I will double check front bearings, and wondering if anyone has used larger c-clip retainers?
Possibly the stock master does not have a large enough bore?
Goal is to get brakes to work as well as my 2013 1le.....
ABS is gone.

searching for all input,
thanks Rich

hookdup

Come on , some has to have insight, on long brake travel....
I have to get straightened for next HPDE event..
And I do not want to make a science/physics project out of it.....
Looking for any and all proven or failed fixes!!!!
Please help...

.boB

iTrader: (1)

Sounds like you have air in the system.

hookdup

Bled to flush system, and fill with SRF. No air at all noted, does have quick disconnects on front calipers, and single for rear, but no leaking, and pedal is not compressible once all take up is pedaled out of system.
Rear calipers appear are labeled PBR, as prior stated,
replaced front rotors and hats with all new wildwood components,
Problem or perception was noticed bty the car that was following me, as I was braking (well brake lights) where I never braked before.
I took as being safe and trying to set pads. He took as something wrong...

Any insight as to residual pressure valve, and would be in front or rear?

ABS has been removed prior to me, and was competitive without.
Just trying to sort!!!!!!!!

79_T/A

iTrader: (1)

If you pump the pedal once does it come back? I have the same brakes and the fixed caliper is incredibly sensitive to worn hubs. Unbelievable amount of knock-back.

1981TA

iTrader: (7)

Look at the thread linked in my footer. I had the same issue and ended up converting to Ford style bolt in axle setup. Other options include going to a 9-inch rear end or some other form of c-clip elimination in back. Not cheap, unfortunately.

Fox408

iTrader: (1)

Not sure if it relates or not, but I've had long pedal issues when have a brake master cylinder going out.

hookdup

long pedal goes away, after initial set,
not trying to reinvent the wheel, just looking for best experiences.
Will just swap front bearing to set benchmark, as I only purchased car 2
months ago, ( 7 heat cycles on tires)
but not sure of the rear calipers, , as they are marked PBR,
not sure of fin design,
Could it be the stock master is not capable of the fluid amount required for
WW 6SLR calipers,
it does have a proportioning valve, which I chose to no touch, since my
history dictates it will create a leak, or problem!!!!!!!
( Needless to say, after I purchased the car, it was my own fault, as I failed
to check the trans fluid level on a supposedly just rebuilt trans,
I SNAPPED the Input shaft, due to NO
FLUID IN THE TRANS>>>>>>>
So it now has a Son of Tranzilla t56, and anGM perf parts LS7 CLutch and flywheel setup

79_T/A

iTrader: (1)

The stock master cylinder is fine, you are just experiencing the hell that is the 4th gen f-body hub. With sticky rubber they don't last very long. There are a couple of expensive solutions to the problem.

hookdup

16 years after first of production, SOMEONE...
has have to had this figured out!
( Excepting getting a Z06)
I am going to replace the front hubs, with Timken units, to eliminate those,
Has anyone had positive improvement with 2 lbs residual pressure vales in both front and rear?
How about a hydro boost unit?
I really do not want to go to a 9" rear, the 7.5 has been there, and proven itself, for the past 16 years.....
Maybe someone knows of a c clip eliminator kit like used to made for old 10 and 12 bolts????
Possibly an adjustable pushrod,
or
do I just re-engineer everything and go with a tilton pedal set up?
Has this been done...
I know I am reaching into the antiquated archives...
But the car is fun, especially for HPDE

79_T/A

iTrader: (1)

I'm telling you, the pad knock back from these front hubs is atrocious. They don't last very long, especially on sticky rubber. Even when the hubs are fresh you get knock back. I will send you a message on FRRAX about some solutions to the problem that are being worked on.

1981TA

iTrader: (7)

Wow. I'm glad I don't have to deal with 4th gen style front wheel hubs. The worst I've had to do with my spindles is replace a $5 Timken bearing ($8 if you get the top shelf one).

For what it's worth, the bore on my brake master is 1" and I'm running manual brakes.

There are a few ways to eliminate C-clips without having to go to a 9-inch, but you'll have to carefully research them to make sure one will work for you. In a nutshell, I think these are your choices:

1. Traditional ball-bearing C-clip eliminating axle bearings. These tend to be limited to drag use only, I think because they might leak with regular driving.
2. Strange Engineering supposedly has a different design which will cost a bit more, but also doesn't leak.
3. Convert to bolt-in axles. Moser sells the axles and housing ends. You will have to cut your axle tube ends off and weld on the replacements. It cost me $600 in parts.

I'm sure all of them have fans and detractors. No matter what, you will need to check if any of these approaches mess up things like ABS or parking brakes. Call the manufacturers - the guys at Strange and Moser are very helpful and may come up with options that my caffeine-deprived brain is missing.

I went with the bolt-in axles, and *probably* could have worked e-brakes into the picture, but I didn't want to mess with it. This is a pic of a 8.5" 10-bolt with the Moser axles and mountings for 4th gen LS1 rear brakes.