Rear brakes both side are not working. Pulled wheels and looked at action of pads and rotors did not appear to be grabbing rotors. Front work great. Car will not stop to good when they are hot. What is my problem. Good pad rotors good in good shape. Oh, car has been setting for two years that I know of. Info from another source say that it may have sat for ten years.
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Re: rear brakes -76 StringRay
Al----
Corvette calipers and pads are "constant contact" type. Therefore, it is difficult to tell if they are functioning properly simply by having a helper activate the brake pedal and observing the pads. You might be able to tell something by having someone activate the brakes and then trying to turn the wheel with the wheel off the ground. However, even this won't tell you much because even a little braking power would prevent you from turning the wheel by hand.
Assuming for the moment that you are correct about the rear brakes not functioning, there are several possibilities. First, all of the fluid could have leaked out of the rear braking circuit. Check the master cylinder to determine if this is the case. Second, the rear braking circuit, even if full of fluid, could have significant air in it. This will reduce the braking effectiveness of the system to zero or near zero. Third, your master cylinder secondary circuit could be defective and thus generating no secondary circuit pressure.
There are other possibilities, but I'd check these first. If the car has been sitting for as long as you say, a complete brake system rebuild might well be in order. This is especially true if it's never had stainless steel lined calipers installed.In Appreciation of John Hinckley -
Re: rear brakes -76 StringRay
Al----
Corvette calipers and pads are "constant contact" type. Therefore, it is difficult to tell if they are functioning properly simply by having a helper activate the brake pedal and observing the pads. You might be able to tell something by having someone activate the brakes and then trying to turn the wheel with the wheel off the ground. However, even this won't tell you much because even a little braking power would prevent you from turning the wheel by hand.
Assuming for the moment that you are correct about the rear brakes not functioning, there are several possibilities. First, all of the fluid could have leaked out of the rear braking circuit. Check the master cylinder to determine if this is the case. Second, the rear braking circuit, even if full of fluid, could have significant air in it. This will reduce the braking effectiveness of the system to zero or near zero. Third, your master cylinder secondary circuit could be defective and thus generating no secondary circuit pressure.
There are other possibilities, but I'd check these first. If the car has been sitting for as long as you say, a complete brake system rebuild might well be in order. This is especially true if it's never had stainless steel lined calipers installed.In Appreciation of John HinckleyComment
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Re: rear brakes -76 StringRay
Have you checked for brakwe fluid loss in the rears? Start by checking the master cylinder, if that is ok, then try bleeding the brakes. If you get air out of the rear calipers, most likely they will need rebuilt Stainless Steel lined calipers are readily available from a variety of sources. I generally use Dr. Vette with good results.Comment
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Re: rear brakes -76 StringRay
Have you checked for brakwe fluid loss in the rears? Start by checking the master cylinder, if that is ok, then try bleeding the brakes. If you get air out of the rear calipers, most likely they will need rebuilt Stainless Steel lined calipers are readily available from a variety of sources. I generally use Dr. Vette with good results.Comment
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Re: rear brakes -76 StringRay
Al, Bill has a good point, I would start with the bleeders at the rear calipers )after making sure the master cylinder is full). You said that the car has set for 2 years (or maybe 10), if it has the original calipers, I would bet the pistons are seized in the calipers. This is not uncommon for OEM calipers. If they are, again Bill has the right idea on replacement with aftermarket calipers with stainless steel sleeves. I replaced my OEM calipers about 10 years ago. FYI, on bleeding, Vettes are fun to get the air out of the system. I found it best to gavity bleed the system. Note: There is the possibility of a bad master cylinder. Goodluck. if you need more info, drop me an E=mail. Also, I would be interested in what you find.Comment
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Re: rear brakes -76 StringRay
Al, Bill has a good point, I would start with the bleeders at the rear calipers )after making sure the master cylinder is full). You said that the car has set for 2 years (or maybe 10), if it has the original calipers, I would bet the pistons are seized in the calipers. This is not uncommon for OEM calipers. If they are, again Bill has the right idea on replacement with aftermarket calipers with stainless steel sleeves. I replaced my OEM calipers about 10 years ago. FYI, on bleeding, Vettes are fun to get the air out of the system. I found it best to gavity bleed the system. Note: There is the possibility of a bad master cylinder. Goodluck. if you need more info, drop me an E=mail. Also, I would be interested in what you find.Comment
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Re: rear brakes -76 StringRay
Thanks to everyone, I bled the rear's over the weekend at first they came up real good but after setting for a while (4 hours) at got the same problem will put a new master on this week. I did notice a cloud of something in the master when I added new fluid to it. Will drain entire system with new master. My last step will be to replace the rear hardware. Lucy there is a place here that has them. Again thanks to everyone for their help.Comment
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Re: rear brakes -76 StringRay
Thanks to everyone, I bled the rear's over the weekend at first they came up real good but after setting for a while (4 hours) at got the same problem will put a new master on this week. I did notice a cloud of something in the master when I added new fluid to it. Will drain entire system with new master. My last step will be to replace the rear hardware. Lucy there is a place here that has them. Again thanks to everyone for their help.Comment
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