Brake setup questions

[sharding]

I have a CR Sebring, built by someone else. It has a power disc/drum setup. When I got it, there was about 2”+ play in the pedal before the car started to stop, then it stopped on a dime.

Figuring the play was in the rod between the booster and the MC, I took it to a mechanic to adjust it. Turns out the rear brakes weren’t engaging at all, and once he got that working, the brakes were way too touchy with all 4 working. We swapped out the 15/16” MC for a 1-1/16” bore to decrease pressure, better but still too touchy. The pedal play seems to be in the pedal assembly, which I would also like to fix.

So, what I’m wondering is, why the booster? Seems like it’s not needed, since it’s too easy to stop the car, and I ought to pitch the thing while I’m trying to find the right MC diameter. There is almost no pedal feedback when stopping. Anyone have any thoughts on this?

[Wisconsin_Snake]

Could it be that the person over adjusted your brakes??
The booster should reduce effort required to when pressing on the brakes?
Also what size booster are you running? You can go to a smaller sized booster. A booster size drop from a dual diaphragm 8" to a single diaphragm 7 inch would would be huge.

[FWB]

the car is light with good brakes, mine is the same way, i can bounce my nose off the steering wheel if i don't watch it...

if you just can't live with it, maybe try restricting the vacuum a bit going to the booster....

[MaSnaka]

Is it possible your pedal ratio is set up for manual brakes? That would be a significant increase in pedal pressure with less effort because the pedal would have more leverage on the rod. Maybe the combo of that and a booster is too much. The pedal box has the holes drilled for both set ups but the difference would be in the length of the pedal arm between fulcrum and the cleavis. I have a picture in my gallery showing the difference in pedal arm length. HTH.

John

[sharding]

All good points that I will check out. I believe that my booster is an 8" dual diaphragm, and even though I'm at a high elevation here, I run 21" of vacuum (adjusted). The pictures of the pedal before and after were great, I'll check that next. I have a feeling that it's a combination of things, which is why I didn't want to just keep throwing a bigger MC in.

How could the brakes be over-adjusted? I was thinking that there was just right and not right.

[MaSnaka]

Sharding,
For what it's worth, I have a 15/16ths MC without the booster. I now have 11" Wilwoods on all wheels and the brakes are a huge improvement from where I started. Pedal feels good and solid where I can modulate from soft to hard braking. I started with 9" rotors up front, drums on the rear, a pedal ratio set for a booster but no booster. Brakes were weak, and rolling through a red light with my daughter in the car because I couldn't stop forced me to take action. I know TCRIST here has a booster on his discs and says they work very well. D-CEL has a lot of good brake info in his posts too. Do a search and you should find lots of info on different brake remedies.

John