Brother, can you spare a 60'?

[Keller]

Despite everything I did at the beginning of the year to start my brake system with a clean sheet of paper, I only made things worse.

Despite the larger piston US Brake calipers, fresh Bendix rotors and drums, fresh pads and shoes, plus new S-10 wheel cylinders out back, plus a braided line to the rear end (braided front lines never sealed) I just can't hold it at the line.

My recent trip to the track left me not able to hold any boost at the line, really. Never even touched the 11's. And I am not happy.

Since I did so many things at once, I'm not sure what is 'broke'.

The car seems to stop better than ever. It had good (replacement) pad thickness at all four corners before I touched it. However, the rotors and drums were original. And with 71k, they were getting along. Weren't trashed, but worn. I also went with fresh hardware and bearings.

The front has the larger piston US Brake calipers. Stock lines. Hawk Ceramic pads. Bendix rotors. Fresh hardware.

The rear has a Russell braided stainless line, Bendix S-10 (manual) large wheels cylinders, Satisfied "Metalizer" pads (all 'large' pads used), Bendix drums. Fresh hardware.

Bled the system to death. However, it appears to be down a bit on fluid now. Will check and top off.

The car stops straight with no drama or wheel locking.

The rear pads may be too hard to get good boost launches. I previously had Wearever "Silver" pads from Advanced Auto Parts, with the larger pads from two sets on the car. That setup with the S-10 cylinders locked the rears from the moment I put them on the car for the first 15-20 miles, even under light braking. Even while I was braking in those pads, I thought I would have to rip them right back off. Then the drama cleared. These new pads have never done that. However, it could be the pads, or it could be something in the hydraulic system.

Not sure what to do. I really want it all, yet I know that isn't possible. I want a car that will stop on a dime, and do a bumper-dragging launch with a footbrake leave. Uh...OK, a decent launch.

Should I put in the old pads? Put in a fresh set of 'soft' pads? (Any suggestions?) Put in the old rear line? New soft lines all around and ditch the braided lines? Forget about brake tourque and go with a trans-brake?

I need my 60's back, not to mention some consistency. I haven't even turned an 11.xx at my home track this year. I was hoping the suspension work would a step to help me, not hurt me.

[kenmosher]

I'd put some soft organic (i.e. cheap) shoes on the rear and see if that makes a difference ... step into it one part at a time.

I wonder if the new larger pistons are taking too much fluid volume?

[Phatman]

Originally Posted by kenmosher

I'd put some soft organic (i.e. cheap) shoes on the rear and see if that makes a difference ... step into it one part at a time.

I wonder if the new larger pistons are taking too much fluid volume?

That's just what I was thinking....
I have basically the same problem, my son did the brake work on his GN, less the the US calipers, but with the same results. I was baffled, but while sitting in the shop looking at his handy work I thought I had found the problem, well, I did find one major problem. He had installed the rear cylinders upside down making it impossible to bleed them completely. I'm still confused and can see nothing else wrong other than the fact that he can not hold any boost with the foot brake to speak of...

Good Luck!!!!

[Keller]

Originally Posted by kenmosher

I wonder if the new larger pistons are taking too much fluid volume?

FWIW, being on the front, they should not affect the rear braking due to the split of the brake system, right? Err, maybe?

AND...while I'm thinking about it...I also installed the brass proportioning valve that I've had sitting around for more than a decade and never got around to installing. This was *sort* of a recall as best I can tell. I believe it was an official recall in Canada, and just a recommendation in the US. Brass is not as pourus as iron, and therefore will not allow air transfer into the system.

P/N 25509419, short number 172-1353, group 4.690. Looked it up on acdelco.com and 2022 vehicles are shown in the application list. Among them, the Regals. *whew* Another cause of problems? Who knows...

[PaCemkr86]

if the car stops good and your happy with the braking.. leave em alone
im all for having a transbrake.. its guarnteed to give you wheels up lauches you can be proud of.

I currently have my TH400 w/ brake in my ttype but i also have my PTS 200r with a t- brake im going to put back in. " no O/D sucks"

Scott if you have never raced a car with a transbrake you dont know what you are missing. It gives you the neck snappin lauch everytime with wheels in the air.

But you know as well as i do, if you do go with a transbrake,
Your stongest point will only be as good as your weakiest link..

I say go for it !!

[Keller]

Originally Posted by PaCemkr86

Scott if you have never raced a car with a transbrake you dont know what you are missing.

I haven't. And now that I have more beef out back, it is tempting.

Though I would want to toss more meat in the trans and driveshaft depatments, too. I really don't feel like walking home from the track...

Maybe just a little further down the road. Don't want to correct the current problem by thowing a bigger bomb at it.

[shorti28]

I also had this no boost on launch.. What I believe was the issue all along.... a bad boost gauge. I could not build boost on the line and just happened to switch to autometer guages and Immediatly saw 5 lbs boost on light foot braking. I have the same brake mods as you and this may not be your problem but it was definitly mine. Worth a check!

[Keller]

I do not have no boost on launch. The car starts to spin the wheels when I do build boost on launch. I then have to pull my foot out, and then end up leaving with no boost or at near 0 boost. I assure you, the car has boost just fine. And ~25 PSI through the traps. Having a hell of a time cutting a light, not to mention I have not even come close to getting near my best ET from last season.

Picked up one pair of orgainic shoes. Another pair coming in Sunday so I can use the 'long' shoes from each. I'll swap them on, top off the system and bleed if necesary. Debating trying to get the front metal lines on. Not to mention those new US Brake calipers are already getting a rusty haze on them. Perhaps just dealing with one minor disaster at a time is best.

If the organics don't do it, I may jump to a trans brake. The rear end is already beefed up. However, some trans parts may need a bit more. I was thinking of waiting until after next season. Missouri just passed a new inspection bill that does away with emissions inspections for pre-1996 vehicles - takes effect September 2007. I still have to go one more time in May 2007. Thought I might step things up after the 2007 season and celebrate the car's 20'th annversary. Perhaps a fresh motor with decent goodies, tranny with some extra beef, turbo to aspirate the animal, and some larger injectors to feed the fire. Anyway...off topic.

I have a brake issue. That is the first problem.

[PaCemkr86]

please go with the transbrake.. You will have major gain in the 60ft with the front wheels in the air.

[Keller]

Well, shoot me some info on 'em.

Meanwhile, I've been going crazy looking at brake shoes. Not sure anyone even makes non metalic shoes anymore. The ones I had come only metallic now. The "organic" ones I purchased look like glitter and are rough to the touch from the metal pieces. The Satisfied ones one the car are too, only darker. Managed to find a set at AutoZone that appear to be non-metallic (by appearance) that I might try. Could get some pics up tonight or tomorrow.

If you know of any shoes that are definitely non-metallic, give me a heads-up.

Meanwhile, 100F+ is a little too hot to race and get a good number, so I'm not even going to bother wrenching...