break pedal/bearing?
04-14-2012, 07:07 PM
#1
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Thread Starter
break pedal/bearing?
thoughts...
purchased a 1979 vette that has 37,000 miles last year in the spring.
I replaced all 4 calipers, the master cylinder, bled and had a nice hard
pedal. Replaced a lot more stuff that had rotted or just fell off or was taken off, but back to my issue.
drove the car and was surprised that i had a pedal pulsating, I have been a certified master mechanic for 20+ years so breaks are not a issue, even old vette's . removed the front wheels and checked and didn't like the look of the rotors so i replaced them this year, and still with the pulsating. so i started in the rear.
put the car on jack stands and removed the wheels and threw on 2 lug nuts on the rotors, started the car and had the assembly spinning. What i didn't see was any major run out or wobble...i was walking around the back of the car to look at the other side and saw the hole TA moving, not much but a little... about as much pedal pulsating. I got it U-Joints!
pulled both haft shafts and saw that although they were rusty and ugly too look at, the u-joints were not frozen or damaged. looked at the bearing/hub and spun them by hand. they both seem tight and smooth.
I don't really believe my bearings were going bad, no growl noise... other than the humm from the ring and pinion. and now i dont think my u-joints are bad and it seems my rotors are not warped. why would my TA's move when the wheel is spinning ?
p.s. i will probably replace the rotors, u-joints and maybe a shock absorber's I am in there right ?
purchased a 1979 vette that has 37,000 miles last year in the spring.
I replaced all 4 calipers, the master cylinder, bled and had a nice hard
pedal. Replaced a lot more stuff that had rotted or just fell off or was taken off, but back to my issue.
drove the car and was surprised that i had a pedal pulsating, I have been a certified master mechanic for 20+ years so breaks are not a issue, even old vette's . removed the front wheels and checked and didn't like the look of the rotors so i replaced them this year, and still with the pulsating. so i started in the rear.
put the car on jack stands and removed the wheels and threw on 2 lug nuts on the rotors, started the car and had the assembly spinning. What i didn't see was any major run out or wobble...i was walking around the back of the car to look at the other side and saw the hole TA moving, not much but a little... about as much pedal pulsating. I got it U-Joints!
pulled both haft shafts and saw that although they were rusty and ugly too look at, the u-joints were not frozen or damaged. looked at the bearing/hub and spun them by hand. they both seem tight and smooth.
I don't really believe my bearings were going bad, no growl noise... other than the humm from the ring and pinion. and now i dont think my u-joints are bad and it seems my rotors are not warped. why would my TA's move when the wheel is spinning ?
p.s. i will probably replace the rotors, u-joints and maybe a shock absorber's I am in there right ?
04-14-2012, 08:28 PM
#2
Le Mans Master
Member Since: Jul 2006
Location: charlotte north carolina
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when the trailing arms are hanging down, they're much lower than at ride height. this causes interference contact with the hub and u joints. if you turn the wheels by hand, you will feel them hit and bind and "jump". nothing to worry about.
04-14-2012, 09:03 PM
#4
Melting Slicks
Because the Corvette calipers are not a floating design warped calipers won't usually cause pedal pulsation (although it will cause them to suck air past the seals). Pulsation is usually caused by a rotor that varies in thickness. Take your rotors off and use a micrometer to measure the thickness at a number of points. If they are out, have them turned.
