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View Full Version : brakes binding need help asap



nasty50
02-06-2011, 09:10 AM
So I finally had the cpp brake kit (drum to disc up front)put on even bought all new hard lines from front to rear.While the the car is up on stands the wheel spins freelly no bindind or uneven caliper install.71 chevelle drives fine but there's time when ill either take it for a 30 minute drive with no issues Or just to the store 5 minute drive and I can feel the pedal is hard and brakes are engaged.
After I park the car for awhile its normal again.

I thought maybe the lines being close to headers it heats up and causes the brake fluid to expand but
Like I said sometimes a quick 5 min drive would cost this also(brake line up against firewall like stock).

I hope somebody helps me asap we been having a 70 degree weather in sf cali on winter and would love to cruise thanks again in advance.

CPPAaron
02-07-2011, 07:29 AM
This sounds like there is pre load in the master. Try adjusting the pedal up a bit and checking when the masters installed it does not pre-ingage the piston when the vacuum kits in. You can also pull the vaccuum source and drive it and see if it still does this.

nasty50
02-07-2011, 11:33 AM
what I did is adjusted the pedal closer towards firewall that's what you mean right?seems like it helped but won't know till I drive it more.ill also try to unplug vacuum if it happens again ill keep you posted.by the way since I adjusted the pedal its now far from the brake light sensor so what I did is bend the metal tab a bit just enough to hit the sersor,that should be okay right?(sensor all ready srewed in all the way)

CPPAaron
02-07-2011, 01:27 PM
Let me know how that works for you after you drive it some.

nasty50
02-11-2011, 03:42 PM
This sounds like there is pre load in the master. Try adjusting the pedal up a bit and checking when the masters installed it does not pre-ingage the piston when the vacuum kits in. You can also pull the vaccuum source and drive it and see if it still does this.

K aaron I drove is like 5 miles and notice in the freeway a strong smell like brakes.although
It wasn't. As bad as before you can tell its still touching.I can't adjust the pedal any more cus if I do the brake lights stays on(the brake sensor where it touches tthe pedal is adjusted all the way)I even tried adjusted more than I could and just bend the metal tab but that's it.

I didn't try to unplug vacuum if I do won't that make my brake pedal hard?if I unplug it and it releases the brake what does this mean?I also asked which rod inside the masterr cylinder was used eitheer the short or long and I was told the shorter one.

CPPAaron
02-11-2011, 03:49 PM
By pulling the vacuum line it will tell you if the booster is preloading the master under pressure. At that point you would shorten the pushrod between the master and the booster itself.

nasty50
03-06-2011, 08:57 AM
ok aaron i finally had time to trouble shoot and found out that iam leaking brake fluid right at the bleeder screw,i thought it was loose so i checked and it was actually super tight.so i loosen a bit plugged a vacuum bleeder pump and got non stop of air bubbles so i thought it was that but again every time i pump the bubble just kept coming.thats when i noticed the bleeder valve might be the wrong size on there.

all it takes is not even a 1/4 turn and the valve moves side to side so bleeding cant be done by vacuum.i tried the 2 man system one pumps and one releases the bleeder screw and that works fine but after driving for awhile i noticed fluid leaks out a bit.

any idea on the right size of the bleeder screw?i might just order the speedbleeder it shows you have 3 different sizes.i cant even go with the ones on there cus i have a feeling there the wrong size.theres no loose its either verry loose or thight.please aaron help thanks in advance....

oh yeah i got the 11.5 kit for 71 chevelle with the upgraded rotors and powder coated calipers.

CPPAaron
03-07-2011, 08:18 AM
The speed bleeder will work great in this application and with the issue you are having. The speed bleeder is a little taller and has more threads. The bleeder you need is #SB1015 10mmx1.5 pitch

nasty50
03-07-2011, 01:27 PM
Is this a common issue with the bleeder screw that comes with the caliper?I bought some speed bleeder from local parts store ill leep you posted thanks.

CPPAaron
03-07-2011, 01:44 PM
No not very common.....

nasty50
03-12-2011, 08:36 AM
So far so good aaron thanks for the advise I went ahead and pull the master cylinder and shaved off about 16th" and seems to be the culprit.I know ao my second post I said I pulled of the vacuum
Atleast that's what I was told by a friend of mine that drove it for abit.anyways thanks again aaron.

nasty50
03-12-2011, 07:25 PM
Okay took her for a long drive and seems like its still binding but not as much as before just a little bit.when I get some time tomorow ill probably shave some more off so my question is is there taking to much?I only took of 16th" and iam thinking I need maybe another 16th" will this be okay?

CPPAaron
03-15-2011, 06:42 AM
split the differance; shave 1/32"

nasty50
05-22-2011, 10:39 PM
So I ended up shaving another 16th maybe even more and its been good but today went for a long drive 60 miles and noticed pedal got hard and although it wasn't binding when I stopped and got off the car I still smell brake pads like i t was still touching a bit.anymore suggestions?should I shave more?it always starts out good with good pedal play and preasure but gets real hard after a long drive.

Iam also upgrading to a rear disc kit also cpp at a local add here brandnew kit for $300.
Will my current master cylinder and brake booster be okay?
Thanks in advance.

CPPAaron
05-23-2011, 07:04 AM
Sounds like shaving the pin is helping. I would go another 1/32". If you change to a rear disc kit all you have to do is follow these instructions for the proportional valve:
Classic Performance Products (http://www.classicperform.com/Instructions/PDF/Prop_Valve_Mod_Instructions.htm)