Brakes, Probably again....
Thread Starter
Heel & Toe
Joined: Feb 2006
Posts: 17
Likes: 0
From: Hopkinsville Kentucky
Brakes, Probably again....
Hello everyone,
I have an orange 77 L48 4sp car with 89k original miles. It's had some work done to it, but not much. Yesterday, I lost my brakes. I checked the fluid in the master cylinder and its full. Two years ago one caliper was replaced on the front as well as rotors and pads on the front, but I haven't checked yet, but I'm wondering if worn back brake pads would cause a problem. It still stops, but the pedal goes to the floor. The vacuum booster seems to be working. Any suggestions?
Thanks,
Stuart
I have an orange 77 L48 4sp car with 89k original miles. It's had some work done to it, but not much. Yesterday, I lost my brakes. I checked the fluid in the master cylinder and its full. Two years ago one caliper was replaced on the front as well as rotors and pads on the front, but I haven't checked yet, but I'm wondering if worn back brake pads would cause a problem. It still stops, but the pedal goes to the floor. The vacuum booster seems to be working. Any suggestions?
Thanks,
Stuart
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by orange77
Hello everyone,
I have an orange 77 L48 4sp car with 89k original miles. It's had some work done to it, but not much. Yesterday, I lost my brakes. I checked the fluid in the master cylinder and its full. Two years ago one caliper was replaced on the front as well as rotors and pads on the front, but I haven't checked yet, but I'm wondering if worn back brake pads would cause a problem. It still stops, but the pedal goes to the floor. The vacuum booster seems to be working. Any suggestions?
Thanks,
Stuart
I have an orange 77 L48 4sp car with 89k original miles. It's had some work done to it, but not much. Yesterday, I lost my brakes. I checked the fluid in the master cylinder and its full. Two years ago one caliper was replaced on the front as well as rotors and pads on the front, but I haven't checked yet, but I'm wondering if worn back brake pads would cause a problem. It still stops, but the pedal goes to the floor. The vacuum booster seems to be working. Any suggestions?
Thanks,
Stuart
Sounds like waaay too much air in the system, probably due to rotor wobble. I would suggest a complete overhaul. Replace all the rotors and make sure all the calipers are sleeved with stainless steel. Check all your rubber hoses for rot and replace as needed. The, bleed and get all the air out. Your booster is probably okay.
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You may have a bad master cylinder despite the fact that it doesn't leak.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,482
From: Southbound
Cruise-In II Veteran
Originally Posted by Durango_boy
...Sounds like waaay too much air in the system, probably due to rotor wobble....bleed and get all the air out. Your booster is probably okay.
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
I had the same problem...
I had a bad master cylinder - even though it didn't leak.
I recomend - getting a new master cyliner - only $30
Checking all the pads - replace as needed
Check rotors - replace, or machine as needed
Change the fluid in whole system... using a vaccum that you connect to the bleed screw... make sure you keep putting fluid into the master cyl so you don't suck air in... do this a few times on each caliper to make sure you get all the old fluid out and new fluid in. This will also get the old fluid out of the calipers... and will confirm if the caliper function properly... you should see the pistons retract when the vaccum is on the nipple... when you press the petal the pistons will come back out.
Dont forget to bench bleed the new master cyl before installing it.
I had a bad master cylinder - even though it didn't leak.
I recomend - getting a new master cyliner - only $30
Checking all the pads - replace as needed
Check rotors - replace, or machine as needed
Change the fluid in whole system... using a vaccum that you connect to the bleed screw... make sure you keep putting fluid into the master cyl so you don't suck air in... do this a few times on each caliper to make sure you get all the old fluid out and new fluid in. This will also get the old fluid out of the calipers... and will confirm if the caliper function properly... you should see the pistons retract when the vaccum is on the nipple... when you press the petal the pistons will come back out.
Dont forget to bench bleed the new master cyl before installing it.
Racer
Joined: Jun 2005
Posts: 460
Likes: 0
From: Point Pleasant NJ
it has been my experience that if the pedal goes to the floor and there is no leaking.... it is the master cylinder. I was told a good way to test this is to try and pump your brakes up. If you pump the pedal a few times and the pedal gets harder then goes to the floor... the secondary seal is bad on the master cylinder... they are cheap enough to buy and even easier to replace. If you end up replacing it, get a master cylinder bleeder kit to aid in bench bleeding it. Napa sells it for 7 dollars. Well worth it.
Just something to try!
goodluck.. brake problems S*#K!
Just something to try!
goodluck.. brake problems S*#K!
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Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by lil75vette
it has been my experience that if the pedal goes to the floor and there is no leaking.... it is the master cylinder. I was told a good way to test this is to try and pump your brakes up. If you pump the pedal a few times and the pedal gets harder then goes to the floor... the secondary seal is bad on the master cylinder... they are cheap enough to buy and even easier to replace. If you end up replacing it, get a master cylinder bleeder kit to aid in bench bleeding it. Napa sells it for 7 dollars. Well worth it.
Just something to try! goodluck.. brake problems S*#K!
Just something to try!
goodluck.. brake problems S*#K!I rebuilt my chrome one so I didn't have to spring for another expensive one and it was only $35 and maybe a hour total, including removal.
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
Bleed the brakes all around....should fix it temporarily...I have a rear driver side caliper that takes on air every 6 months....when I bleed just that caliper, I'm back in business again...I suspect rotor wobblle, but could be a bad cal...no leaks, no dripping fluid, MC is full, just soft brakes....I think it's just an inherent trait....good luck
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by kb2fzq
Bleed the brakes all around....should fix it temporarily...I have a rear driver side caliper that takes on air every 6 months....when I bleed just that caliper, I'm back in business again...I suspect rotor wobblle, but could be a bad cal...no leaks, no dripping fluid, MC is full, just soft brakes....I think it's just an inherent trait....good luck
That wobble can cause the caliper too fail if the runout gets too bad, and you may lose brake pressure all together. It'd be safe to just replace the caliper, turn the rotor, and solve all the problems there.
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by lil75vette
it has been my experience that if the pedal goes to the floor and there is no leaking.... it is the master cylinder.
I have seen the same symptoms and it was caused by the caliper sucking in air.
Wether it was rotor related I dont know
I installed a new caliper .... bled the brakes and all was fine
Same problem with a diferent wheel about 6 months later and the same fix worked perfect again
Brakes are still very strong and the pedal is up very high
Advanced
Joined: Sep 2005
Posts: 62
Likes: 0
From: Gardner Kansas
I have had the same problem more than once... It is almost definetly too much air in the lines caused by rotor wobble... you can bleed them and be back on the road in a couple of hours but it's just a matter of time before your back in this situation, and let me tell you there is nothing more hair raising than stepping onto that pedal and it goes to the floor...
VBP has a nice kit for sale around $500.00 M/C, S/S sleeved calipers, rubber lines, pads, & fluid .... Great value, VBP also has a OLD post for a 10% disount for forum members. It is my understanding that they will still honor it.
You will definetly want to replace the rotors also... tons of options there as well.
Good luck... These are your brakes we're talking about here .... spend the money.
VBP has a nice kit for sale around $500.00 M/C, S/S sleeved calipers, rubber lines, pads, & fluid .... Great value, VBP also has a OLD post for a 10% disount for forum members. It is my understanding that they will still honor it.
You will definetly want to replace the rotors also... tons of options there as well.
Good luck... These are your brakes we're talking about here .... spend the money.
Race Director
Joined: Mar 2006
Posts: 14,112
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From: Florida
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by noonie
Good one...saved a copy.
Also, rotors can sometimes be turned to make true again...a lot cheaper than new ones if they are the within tolerences and money is an issue.
Racer
Joined: Sep 2006
Posts: 484
Likes: 0
From: McComb Ms.
i just bought a master cylinder from o'reillys for $18 the rebuild kit was $20.You can rebuild all your calipers for about $40 plus brake fluid and cleaner.I had to replace one caliper that had a groove in it and it was $60 for that. they actually had it in stock at oreilly's. Very simple job. While your there change your rubber lines to SS braided another $80
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Bottom line, if you have an issue with one or all of your brakes...it the most important area to pay close attention to getting fixed. It's a featuire of the car that when bad can be a HUGE safety issue. It can be done cheap, as many have said, but please don't let it be the project that keeps getting put off. If you have a brake problem get it fixed. Plain and simple.
Thread Starter
Heel & Toe
Joined: Feb 2006
Posts: 17
Likes: 0
From: Hopkinsville Kentucky
Hello Yall,
Thanks for all the help. I don't want to skimp on the brakes and don't plan on it. The master cylinder was replaced about 3 years ago. One front caliper was replaced as well as the front rotors and pads about 2 years ago. I'm thinking it's probably in the back brakes as those have not had any work done to them since I have owned the car, but I will check everything just to be safe. I average about 3500 miles a year on the car, so it does sit, but most of the driving it gets is around town. The longest trip I've had it on is a 3 hour one way.
Thanks again and this is a great place to find information....
Stuart
Thanks for all the help. I don't want to skimp on the brakes and don't plan on it. The master cylinder was replaced about 3 years ago. One front caliper was replaced as well as the front rotors and pads about 2 years ago. I'm thinking it's probably in the back brakes as those have not had any work done to them since I have owned the car, but I will check everything just to be safe. I average about 3500 miles a year on the car, so it does sit, but most of the driving it gets is around town. The longest trip I've had it on is a 3 hour one way.
Thanks again and this is a great place to find information....
Stuart