Brake problem any ideas?
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Joined: May 2005
Posts: 64
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From: Macedonia OH
Brake problem any ideas?
I took my '79 vette out for a ride for the first time this summer yesterday. It is a true weekend driver, and only has 30,000 miles on it. It spends alot of time sitting in the garage and is driven only about 25 miles a week in the summertime. Pulling out of the driveway, I noticed the brake light lit up and I had to push the brake pedal almost all the way down to the floor to get the car to stop. There is no squeaking in the brakes or pulling to either side. I checked the brake fluid, which was down slightly. Any idea of what might be wrong?
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You've either got a leak from one of the calipers or you have air in the line and need to bleed the brakes. Check the insides of your tires for wet spots. If there aren't any try bleeding the system. If that doesn't do it you could have a master cylinder problem. Also check all your brake lines for leaks. Cars that sit alot can pick up alot of moisture. You may want to consider purging the system and putting new fluid in. Good luck.
Drifting
Joined: Jan 2006
Posts: 1,944
Likes: 22
From: Yooperville MI
Since the fluid was only down slightly and given the age of the car, it's time to check the entire brake system for leaks and the condition of the rubber hoses. As mentioned, an obvious leak where fluid is running down the tire or wheel or a slight leak where you need to feel around each caliper for wetness. It's possible one of the caliper seals is starting to leak and sucking in air as one or more caliper piston moves in and out due to a rotor being out of spec. If the car sits a lot and you want dependability, you should consider calipers with oring seals.
Instructor
Joined: May 2006
Posts: 168
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From: Florence NJ
If you have to bleed the brakes GM recomends this method (corvette shops follow this as well):
Bleed in this sequence:
Rear Left Inner
Rear Left Outer
Rear Right Inner
Rear Right Outer
Front Left
Front Right
*Please remember to attach a rubber tube to the bleeders and submerge the open end in a clean jar. *
1) Now have your helper pump the brake pedal until it gets hard.
2) With his foot OFF the brake pedal open up the bleeder.
3) Have your helper press the brake pedal to the floor and hold it there.
4) Close the bleeder.
5) Have your helper release the brake pedal.
6) Repeat steps 2 through 5 until no air bubles remain in the fluid being bled.
Hope this helps!
Bleed in this sequence:
Rear Left Inner
Rear Left Outer
Rear Right Inner
Rear Right Outer
Front Left
Front Right
*Please remember to attach a rubber tube to the bleeders and submerge the open end in a clean jar. *
1) Now have your helper pump the brake pedal until it gets hard.
2) With his foot OFF the brake pedal open up the bleeder.
3) Have your helper press the brake pedal to the floor and hold it there.
4) Close the bleeder.
5) Have your helper release the brake pedal.
6) Repeat steps 2 through 5 until no air bubles remain in the fluid being bled.
Hope this helps!
Thread Starter
Advanced
Joined: May 2005
Posts: 64
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From: Macedonia OH
From a worst case scenario standpoint...if I had to replace all of the brake lines, hoses, seals and master cylinder due to deterioration from the car just sitting in the garage and lack of use, would this be a very costly repair?
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Not to bad, VBP has a pretty good deal on parts and it should not cost a lot to get it done. But you can do it yourself, 1 day project.
The light came on because of low pressure on one side of the brake system. There is a gizmo under the MC called a proportioning valve, it has a safety shuttle inside and an alarm switch that turns on the light. It will need to be reset once the system is fixed. Like the above posts, look for leaks, fix what you find and bleed system.
The light came on because of low pressure on one side of the brake system. There is a gizmo under the MC called a proportioning valve, it has a safety shuttle inside and an alarm switch that turns on the light. It will need to be reset once the system is fixed. Like the above posts, look for leaks, fix what you find and bleed system.
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Instructor
Joined: May 2006
Posts: 168
Likes: 0
From: Florence NJ
I just redid all my brakes. New SS lines, SS braded hoses, calipers, rotors, pads, MC and the P valve.
Lines- kit w/ armor - $145
Caliper. Pads, SS braided hoses, Rotors, Fluid - $553 (After core of Calipers and P Valve)
P Valve - $55
MC - $30
Total - $783
Lines- kit w/ armor - $145
Caliper. Pads, SS braided hoses, Rotors, Fluid - $553 (After core of Calipers and P Valve)
P Valve - $55
MC - $30
Total - $783
Instructor
Joined: Jan 2005
Posts: 146
Likes: 0
any of what has been posted
Any of the suggestion could be possible. I would not consider replacing it all until you look for the things mentioned. If you brake pads are to worn, you might experience what you stated. Booster is a possibility, as is that valve that has been mentioned. Leaks should be looked for before you rplace all the lines. If you managed to have a lot of water condense over the years, eventually you might experience the same problem due to water in the fluid. We need you to check these things before you replace it all. Hope this helps
Instructor
Joined: Oct 2005
Posts: 147
Likes: 0
From: Lafayette IN
I replaced all lines, calipers (o-ring design), and the MC for around $600. Go to VBP for your brakes and check the forum for the 10% discount. I like it and it works well, especialy for a first time brake job 
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
I'm not terribly enamored of trusting my life to 20+ year old brake components, either mine or someone elses. I think it's time to start replacing some parts. You'll have a better-functioning system and we'll all have peace of mind.
Safety Car
Joined: Jun 2002
Posts: 4,759
Likes: 2,508
From: Buckeye, AZ
St. Jude Donor '12-'13
Originally Posted by jeckel
If you have to bleed the brakes GM recomends this method (corvette shops follow this as well):
Bleed in this sequence:
Rear Left Inner
Rear Left Outer
Rear Right Inner
Rear Right Outer
Front Left
Front Right
*Please remember to attach a rubber tube to the bleeders and submerge the open end in a clean jar. *
1) Now have your helper pump the brake pedal until it gets hard.
2) With his foot OFF the brake pedal open up the bleeder.
3) Have your helper press the brake pedal to the floor and hold it there.
4) Close the bleeder.
5) Have your helper release the brake pedal.
6) Repeat steps 2 through 5 until no air bubles remain in the fluid being bled.
Hope this helps!
Bleed in this sequence:
Rear Left Inner
Rear Left Outer
Rear Right Inner
Rear Right Outer
Front Left
Front Right
*Please remember to attach a rubber tube to the bleeders and submerge the open end in a clean jar. *
1) Now have your helper pump the brake pedal until it gets hard.
2) With his foot OFF the brake pedal open up the bleeder.
3) Have your helper press the brake pedal to the floor and hold it there.
4) Close the bleeder.
5) Have your helper release the brake pedal.
6) Repeat steps 2 through 5 until no air bubles remain in the fluid being bled.
Hope this helps!
Melting Slicks
Joined: Aug 2003
Posts: 2,135
Likes: 2
From: Dayton Oh
I had the same problem with my 79 when I first got it. I'd bleed the brakes and they would be good for a few weeks before the same thing happened again. I checked for fluid lose but found none. Not knowing what else to do, I replaced the master cylinder but this did not help. Finally I listened to several suggestions on the Forum that my calipers were letting air into the system. Once I changed them out, I've not had a problem in over 2 yrs. Thanks Forum Brothers and Sisters
Navigator
Joined: Jul 2005
Posts: 9
Likes: 0
I agree with everyone above... I had a similar problem with my 77 and needed to replace the calipers as they were letting air in. Sometimes you may not see an obvious leak, but it can still let air in.
Start with the simple tasks... bleed the brakes to see if there is any air in the system. Check to see if your brake lines look cracked or if there is any fluid leaking around the caliper's pistons and replace them if needed. You can pick up rebuilt calipers at Autozone for about $60 each after returning your cores and brake lines are about $12.
If you rule out a caliper leak, move on to the other suggestions above. Replacing brake lines, calipers, and master cylinders are all pretty simple repairs, even for newbies like me.
Start with the simple tasks... bleed the brakes to see if there is any air in the system. Check to see if your brake lines look cracked or if there is any fluid leaking around the caliper's pistons and replace them if needed. You can pick up rebuilt calipers at Autozone for about $60 each after returning your cores and brake lines are about $12.
If you rule out a caliper leak, move on to the other suggestions above. Replacing brake lines, calipers, and master cylinders are all pretty simple repairs, even for newbies like me.