brake problem help!!!
Thread Starter
Pro
Joined: Sep 2007
Posts: 723
Likes: 3
From: pittsburgh pa
brake problem help!!!
last weekend i went on a 350 mile trip to eldora speedway in west ohio to watch late model dirt car race. and ran into some brake problems. first of at speeds over say 65 mph if i got on the brakes hard in traffic i would get a bad pulsating feel. and now it seems like the brake pedal is soft. i can pump them up when using brakes and the are stiff put when i apply steady pressure it seems like they go down to far. not to the floor but damn close. i'm guessing the rotors need replaced. but what would cause the brake pedal to be soft?? would the rotor problem cause that also
???
???
Melting Slicks
Joined: May 2006
Posts: 2,417
Likes: 1
From: No place to legally ride ATV's NJ
You really need to get that thing up in the air for inspection. You could have a combination of old nasty fluid, worn out pads, rotors, and the hoses that go to the calipers. You may even need to rebuild the calipers or replace them (Good time to get the Z06 red ones). Too many things could be wrong, so check it all out.
Melting Slicks
Joined: May 2002
Posts: 2,199
Likes: 1
From: right here right now
CI 5-6-8-9-11 Veteran
You really need to get that thing up in the air for inspection. You could have a combination of old nasty fluid, worn out pads, rotors, and the hoses that go to the calipers. You may even need to rebuild the calipers or replace them (Good time to get the Z06 red ones). Too many things could be wrong, so check it all out.
Advanced
Joined: Dec 2007
Posts: 87
Likes: 1
I agree with DROP THE TOP get it on the lift for inspection. Btw, as far as I know, the c5 and z06 calipers are the same except the z06 are painted red. I just upgraded my brakes using using power slot rotors on the front and Centric blanks on the rear. FYI, Power Slot,Power Stop,Stoptech, are owned by Centric. The hats were painted by the factory, and we put a dial indicator on each mounted rotor to see what the runout was...it was "0" can't get better than that. Also, am using hawk hps pads and ATE racing blue brake fld. Also, repainting my calipers using VHT racing red high heat eng. paint(900º) FYI, previous to this, have gone through 2 sets of gm optional drilled and slotted rotors and after maybe 3 or 4 thousand miles at most of use was also getting terrible shudder in steering wheel and brake pedal..which could be due to warped rotors, or pad lay down material or a combination of both. Also, was using gm ceramic pads. If the new rotors and pads work out I will post in time. Good luck ...Renee
Drifting
Joined: Apr 2007
Posts: 1,496
Likes: 1
From: LEBANON PA.
Hi There:
First thing is to check the brake master cylinder for being full & no black or dirty looking fluid.Also check for leaks through out the system.
Next get a flash light & look at each brake pad front & rear. No need to jack up the car at this point.You can see the thickness of the pads with the car on the ground. Pads that are 1/4" thickness are just about new, 1/8" or less thickness time to change. Next I would raise the car & remove all the wheels (for convenience. you can leave them on) bleed all the brakes using this sequence rr,lf,lr,rf while constantly adding fluid to the m/cylinder. After that you should have a really stiff pedal. If no improvement in the pedal I would suspect internal leakage of the m/cylinder . If you remove the wheels make sure to torque the lug nuts to 100ft.lbs. using a star pattern sequence.This is one of the most common causes of rotor failure improper wheel lug nut torque.
robsc501
First thing is to check the brake master cylinder for being full & no black or dirty looking fluid.Also check for leaks through out the system.
Next get a flash light & look at each brake pad front & rear. No need to jack up the car at this point.You can see the thickness of the pads with the car on the ground. Pads that are 1/4" thickness are just about new, 1/8" or less thickness time to change. Next I would raise the car & remove all the wheels (for convenience. you can leave them on) bleed all the brakes using this sequence rr,lf,lr,rf while constantly adding fluid to the m/cylinder. After that you should have a really stiff pedal. If no improvement in the pedal I would suspect internal leakage of the m/cylinder . If you remove the wheels make sure to torque the lug nuts to 100ft.lbs. using a star pattern sequence.This is one of the most common causes of rotor failure improper wheel lug nut torque.
robsc501
Tech Contributor
Joined: Oct 1999
Posts: 41,063
Likes: 9,826
From: Charlotte, NC (formerly Endicott, NY)
I would put the car up in the air and pull the wheels. Then I would check the brake pads by pulling them out of the calipers and checking them for taper or unusual wear. From there I would inspect the rotors to see if there are excessively grooved or have pitting/delamination of the braking surface (make sure you check both sides of the rotor). Then I would check the calipers and all of the brake lines (metal and rubber) for leaks. If anything needs to be replaced that is the time to replace it. If one pad is bad you will end up replacing all the other pads on that axle, however, if one rotor is bad all you need to do is replace that one rotor. Once everything is back together bleed the brakes and check to see if you still have your pedal issue. If it is still sinking low then you will need to check the M/C.
Bill
Bill
Race Director
Joined: Oct 2007
Posts: 14,107
Likes: 26
From: 4th on the list of top 100 in USA Ga.
Hi There:
First thing is to check the brake master cylinder for being full & no black or dirty looking fluid.Also check for leaks through out the system.
Next get a flash light & look at each brake pad front & rear. No need to jack up the car at this point.You can see the thickness of the pads with the car on the ground. Pads that are 1/4" thickness are just about new, 1/8" or less thickness time to change. Next I would raise the car & remove all the wheels (for convenience. you can leave them on) bleed all the brakes using this sequence rr,lf,lr,rf while constantly adding fluid to the m/cylinder. After that you should have a really stiff pedal. If no improvement in the pedal I would suspect internal leakage of the m/cylinder . If you remove the wheels make sure to torque the lug nuts to 100ft.lbs. using a star pattern sequence.This is one of the most common causes of rotor failure improper wheel lug nut torque.
robsc501
First thing is to check the brake master cylinder for being full & no black or dirty looking fluid.Also check for leaks through out the system.
Next get a flash light & look at each brake pad front & rear. No need to jack up the car at this point.You can see the thickness of the pads with the car on the ground. Pads that are 1/4" thickness are just about new, 1/8" or less thickness time to change. Next I would raise the car & remove all the wheels (for convenience. you can leave them on) bleed all the brakes using this sequence rr,lf,lr,rf while constantly adding fluid to the m/cylinder. After that you should have a really stiff pedal. If no improvement in the pedal I would suspect internal leakage of the m/cylinder . If you remove the wheels make sure to torque the lug nuts to 100ft.lbs. using a star pattern sequence.This is one of the most common causes of rotor failure improper wheel lug nut torque.
robsc501
Master cylinder
