crazypurgatory

So I got my LS1 front brakes on today.
I had to use the LT1's brake hose's because the hydraulic shop was close today.
So I clamped the line and disconnected the lines and put them on the LS1 clappers and I bleed the crap out of them.
I dove the car and it has great front brakes but the pedal goes to the floor.
Whats going on did I some how get air in the rear's?
Now I'm looking at master cylinders at advanced auto parts and the LS1 takes a different master cylinder.
Is that the problem?
All the post I have read about these brakes is that they work great with the stock master.
What gives?
Thanks,


Chris G.

crazypurgatory

OK I just got done bleeding the brakes again.
It is better but I just don't know if it's back to normal.
I wish I could remember what they felt like before.
Do you think I should change the master cylinder.
that seams to be the only difference in the brake system between the LT1 and the LS1?
The rear clappers look like they have the same size or very close to the same piston.
Do you have this set up on your car?
Thanks,


Chris G.

MyShibbyZ28

My stock LT1 brakes can be pushed to the floor with a good amount of force. You do not need the LS1 master cylinder. It is a direct swap. The back calipers are different from the front. On LT1 cars they have single pistons front and back, but I think on LS1 cars the fronts have 2 pistons, and single in the back. I have been wrong before though. Try bleeding the entire system, and see if that helps.

PWR-TRIP

I wanna do the conversion too. Does it make a difference? I just put C6 18 and 19's and my stock brakes sucks.

crazypurgatory

Well the rear clappers look like they have the same size or very close to the same piston on the LS1's.
The only difference is in the parking brake and maybe a bigger rotor.
So I'm thinking I need the LS1's master that might be bigger and flow more to the front's bigger calipers.
I can see a big difference the front dips down under hard braking ABS starts to work.
I'm going to drive it for the week and see how they feel after I get used to them.


Chris G.

Steve0

Are you sure youre getting no leaks at the calipers?

RE AND CHERYL

You don't need the LS1 master cylinder. Bleed the brakes agian and do a four wheels, when you think your done. Keep going. If you allowed the brake fluid to run out while you were installing the brakes you may have let a lot of air into the system.

Gripenfelter

If your master cylinder goes low enough, you will need to bleed the rears.

crazypurgatory

No leaks.
I bleed the crap out of the rears yesterday and it did get better.
The pedal just feels different.
But of course it's going to feel different just don't know.
I do have something odd going on and this was way before I did the swap.
I notice that behind the master cylinder where it mounts to the booster was some brake fluid leaking down from the master cylinder.
So first thing that comes to mind is the master cylinder is leaking.
So I replaced it then a week later it's back so I though the plastic reservoir.
So I replaced that too.
well the leak is back.
That gives I am stumped.
What the heck is going on with that?
let me know what you all think.
Thanks,

Chris G.

wrd1972

The pedal on mine was softer and had more travel after doing the LS1 front brake conversion. There is no need for a different master cylinder, the LT1 is fine.

Also if the pedal is going to the floor you have air in the line period.

Yes the conversion makes a huge difference. The amount of stopping power improvement is incredable plus they dont fade out near as fast.

The only advantage to the LS1 rear brakes is a much improved parking brake and a slight increase in normal breaking to to the 12" rotor. Most people agree that the rear brake conversion is not worth the money.

crazypurgatory

That is how my pedal feels.
That's why I am wondering if the LS1 master cylinder would make a difference.
The LS1's have a different master cylinder.
I would imagine that it is because of the bigger front brakes.
Thanks,


Chris G.

wrd1972

You need to remember that the LT1 caliper and the LS1 calipers are entirely different, therefore they have different operating characteristics. Again my brakes work flawlessly with the exisiting master cylinder. I have yet to hear of anyone needing to upgrade the master. The LT1 has one piston while the LS1 has two pistons. Its kind of like comparing the feel of a V6 to a V8.

Before jumping to conclusions on the correct pedal feeling, maybe you should test the pedal on an actual LS1 f-body. Even though my pedal feels softer the brakes grab much much better.

If you are hell bent on getting the LS1 master have at it, I think its been proven its not required.

crazypurgatory

Thanks for the input.
I think I just have to get used to the difference in the feel of the brakes.
I just need to figure out whats going on with the fluid on the power brake booster.
Thanks,

Chris G.

Fierotom

ohhh, my stock LS1 pedal feeling is very tight with minimum travel!

crazypurgatory

Well that's what makes me wounder about the master cylinder.

Chris G.