Hey guys I just today finished my power disc conversion (had manual drums) and I had to take the chevelle on the turnpike, now the brakes werent feeling right when I first got them but I just wanted to get her home so I could work on them for during the night. now my problem is the pedal is very soft and will on really start to stop when I have them all the way on the floor, but now when its like this it takes a few seconds for the pedal to come up (very slowly), and when I was traveling on the turnpike going aout 60 and started to slow down the brake peadl would get stuck to the floor (scared the ***** out of me) and when I would give it more gas the pedal would come up, I checked the vacuum and i was getting at 5" the most and when i revved her i got 14". Is this pedal problem a sticky booster (what my uncle said) or a vacuum problem like I think, I did put a bigger cam comp 274 but didnt change the converter. will changing the converter fix this or maybe a vacuum canister? or a new booster... thank you so MUCH i have no other way to turn, a teen with no $ and chevelle lol

Really 5" of vacuum? I have heard that 13" is the minimum and 18" is recommended.

However, vacuum only assists in moving the pedal, if the pedal goes all the way to the floor, your brakes should be fully engaged. Something else is not right. Air in the lines, or bad master maybe.

Tim.

Your idle vacuum needs to be around 15 for the brakes to function properly. Did you bench bleed the master cylinder? If not, there is probably air in the system that you need to get out. Also make sure that the rear shoes are adjusted correctly.

I did bench Bleed the Master, and when I step on the pedal I can the Vacuum being pushed its petty loud, I know I in newer cars I have never heard it that loud. could air in the lines be the reasons for the sticking pedal? thanks for the replys guys

do you have the pushrod in the correct hole on the brake pedal? Did you use brake booster vacuum hose for the booster, it has more rigid walls so it won't collapse under vacuum?

cam's to big it sound like. Mine worked better at higher speeds and on the street I had to press on the pedal a little more then I thought even w/ a power booster. Can you at least do a skid stop?If you can do that, your fine, You'll just have to get used to it like some of us around here. Does it feel like u have power assist? Try a power booster test?

What is a skid stop? an how can I perform this power boster test?

I've read posts that lead me to suspect you have the wrong pushrod length, but I have little experience here.
http://www.chevelles.com/forum/ultimatebb.php?ubb=get_topic;f=7;t=006382

Scroll down to the Master Cylinder section, and there's two pics of pushrods care of Joe aka 72SSAbody.

Hope that helps.

JR

See if you can lock up the wheels, but be careful,you don't have to go to fast. To do a power booster test, have the car off first, pump the brakes till the pedal gets hard,hold it there, then start the car and see if the pedal sinks or not.It should sink a little, If it doesn't something is wrong with that booster.
Ike and LeoP are right too, you NEED to have that pushrod connected on the second hole down from the brake pedal,very important when you convert to power brakes. Also, did you install a proportion valve?

I wil give it the booster test tommorow, as far as pushrod length goes, I have the longer pushrod i Hope thats the one Im supposed to have.

and yes I did install a new porpotioning valve

sounds to me like you still have air in the lines. or the valve in the porportioning valve is stuck to one side. does your brake light come on when you apply the brakes. If so you might have to pop the valve back into place.

no the brake light doesnt come on when I step on the brake... but the major problem i have is when I go over 50 the brakes get stuck to floor and the stops very suddenly, it pretty scary...Does anybody knw what could cause this. Also I dont know if this is normal but ever time i stpe on the pedal I hear like a large release of air i guess form the booster is that solund supposed be there

that sound is normal when you step on the pedal. I'm not talking about how long the pushrod is, hopefully they should of gave you the right pushrod, I'm talking about where the pushrod is located on the pedal(where it comes through the firewall to the pedal. There are two holes on the brake pedal. The upper hole is for manual brakes, the lower hole is for power brakes. Makes sure your pushrod is connected to the lower hole on the brake pedal. Very Important because this gives the pedal less travel when applied.

it might be this. take the master off and see if you forgot the rubber bushing that goes between the master and booster. on the bottom of master toward the back theres like a hole that you can close up with your fingers, get someone to push the brakes in while you hold that hole. if you feel air its the seal that goes inbetween the master and booster. check it out