Studiogeek

iTrader: (6)

BUMP!

Has this been sorted out? How does one make sure there is no "dead space" on the pedal?

Ali SC3

iTrader: (10)

I think the consensus was stainless lines all around, bleed the system, and if its still not good enough they do make an upgraded master cylinder for a tt supra but they are pricey and there are 2 different versions used on the SC vs the supra so make sure the number of bolts on it and pattern matches the booster you have in your car.

there were threads about the proper way to bleed the abs system, it has to be actuated to do it properly some old tricks involve lifting the rear wheels and getting it to do it somehow or there is a special tool that can do it, I haven't done it just going off memory what others were discussing. I took away from it that its difficult to do so try not to let air into the system in the first place, but that is easier said than done when changing out brake lines and calipers.

Studiogeek

iTrader: (6)

Thank you AliSC3,
If anyone has any directions for me to give my mechanic, please post them here. This won't be in the service manual for Sc so the guys might be lost.

Thanks Everyone!

fried_rice

iTrader: (20)

I had horrible dead space previously with used LS400 front calipers and stock SC300 rears. Which I bled 100 times and used the best brake fluid available.

I found a good deal on rebuilt LS400 calipers, TT rears and Stainless lines all around. The car is perfect now with amazing performance, road course use braking from 150mph+. I'm not sure if the problem was the old calipers, but I know for sure the lines weren't helping.

I've noticed out of the 20+ SC's I've worked on most of the stock rubber brake lines are cracked and show signs of leaking. For $100 the stainless lines take this variable out of the equation. If you still have dead space rebuild the calipers.

And like stated above most of the SC's have the bigger master cylinder already, so that doesn't do anything. I'm using stock SC master cylinder.

Proper bleeding technique is simple. Start Right rear, Left Rear, Right Front, Left Front, just like any other car. If the brakes haven't been bled in a long time I buy 2 32OZ bottles of Valvoline synthetic, best cheap fluid for street driving and bleed a bottle and a half. I use Castrol SRF fluid at $75 a bottle, it's best fluid out there. Another option is Motul. I use a harbor freight vacuum bleeder connected to an air compressor and sometimes finish off by manually bleeding. With the previous setup, old calipers and stock lines. I tried bench bleeding the master cylinder, replacing the master and activating the ABS pump, which I thought may have been the problem, nothing helped. If your master or ABS has air in it you will have to bleed the brakes multiple times, but it will eventually get all the air out with no special technique.

Blkexcoupe

iTrader: (8)

Has anyone figured this issue out? I rebuilt my master cylinder, rebuilt the tt calipers, and installed new goodridge steel braided lines. I was expecting the brake feel to improve, but I still have a dead space. I've bled it very thoroughly and there is still a dead space like I changed nothing.

beer

double check everything you rebuilt is not leaking. according to previous posters the ABS module/unit is a PITA to bleed and you may have to do some sort of sorcery to get all the air or (or take it to a dealer).

my bet is on the ABS system. it seems others have had the same issue with air getting trapped in it.

AGladski

I have a similar feel to my car. I have the LS400 front calipers with steel braided lines all the way around. I extensively bled the brakes until I had super solid fluid flow, but there still does feel like a small dead spot on the initial pedal press. They bite very firmly after this spot, but the long pedal push is a little funky to me.

Blkexcoupe

iTrader: (8)

Try finding a dirt road or open road where you can safely do this and slam on your brakes repeatedly until your abs activates, then bleed your brakes again after.

BiGEZ

iTrader: (24)

I had the same issue until I upgraded the rears to the Supra TT calipers. Not sure if it was the additional bleeding of the system when I did the rears or the bigger TT calipers. Anyway, I now have a nice solid brake pedal feel every time.
Try the suggestion above to see if that works for you. I the mean time shop around for a set of TT rear calipers.

Blkexcoupe

iTrader: (8)

I've had LS fronts with stock rears and supra tt all around before and both setups were able to brake like normal. The trick is to use hose pinching pliers to pinch the rubber line to keep fluid from coming out (and air from going in) and swap the calipers as fast as possible.

It wasn't until I rebuilt all 4 calipers, rebuilt the master cylinder and changed to steel braided lines that I had issues with pedal feel. The entire braking system was dry for 6 hours while working on the car. I kept on bleeding over and over again, but it never helped. I hooked up a tech stream and there was no abs interface for our cars. I found out the only way to do it is to buy the special toyota module that plugs into the abs (cost about $1k for everything) or I could go out to an empty road and did what I recommended above. I felt the brake pedal improve immediately after engaging the abs. It got even firmer after the follow up bleeding. I documented the entire process in my build thread if you want to see all the things I tried before I figured out what worked.

SpectraBlu

iTrader: (1)

This is great info, thank you I have TT front calipers on my GS and they have the dead spot in the pedal as well but I just got used to it lol. I'm taking them off the GS and putting them on the SC at some point, so this info could be pretty useful.

Blkexcoupe

iTrader: (8)

Thank the guys on ih8mud. They're the ones that gave me the idea.

Just to clarify my previous post, I meant use hose pinching pliers on the rubber lines, not a hose clamp like the kind used on vac lines.