Guess I will have to see what happens. The only thing I can think of that would cause that is a rough surface on the top of the MC.
Brake Bleed Question
Thread Starter
Intermediate
Joined: Nov 2008
Posts: 38
Likes: 0
From: New Jersey
Brake Bleed Question
I am bleeding the brakes on my 1977 Corvette. Pedal seems to be low. No fluid leakage anywhere under the car and master cylinder is filled with brake fluid.
I started from the passeger rear and bled the inner bleeder first, then the outer bleeder.
Heres the problem. I am using a suction canister (not sure of the exact name) the inner bleeder had some air coming out at first but the air appears to have subsided.
The outer bleeder seems to have air coming out continuously. AND when I shut the bleeder valve, a few air bubble still seem to come from the center of the bleeder. At first I thought some air was leaking from around the hose, but it does not appear to be the case (the inner bleeder does not do this). Before I replace the bleeder, or what I was thinking was just get some speed bleeders and make everything easier.
My questions are:
Has anyone else ever experienced this?
Am I doing something wrong?
Does this indicate another problem?
Thanks in advance.
I started from the passeger rear and bled the inner bleeder first, then the outer bleeder.
Heres the problem. I am using a suction canister (not sure of the exact name) the inner bleeder had some air coming out at first but the air appears to have subsided.
The outer bleeder seems to have air coming out continuously. AND when I shut the bleeder valve, a few air bubble still seem to come from the center of the bleeder. At first I thought some air was leaking from around the hose, but it does not appear to be the case (the inner bleeder does not do this). Before I replace the bleeder, or what I was thinking was just get some speed bleeders and make everything easier.
My questions are:
Has anyone else ever experienced this?
Am I doing something wrong?
Does this indicate another problem?
Thanks in advance.
Last edited by Ooglie Googlie; Mar 27, 2010 at 04:30 PM.
Burning Brakes
Joined: Jan 2007
Posts: 1,164
Likes: 1
From: Port Clinton Ohio
St. Jude Donor '08-'09-'10-'11-'12-'13
I tried a vacuum bleeder one time and didn't have any luck with it. It was drawing air through the threads of the bleeder screw. No matter what I did, I couldn't get it to stop doing it. I ended up buying a pressure bleader and that worked great.
Thread Starter
Intermediate
Joined: Nov 2008
Posts: 38
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From: New Jersey
Just ordered it. 
Questions about the pressure bleeder:
Is there a chance of fluid leaking out from under the cap that covers the master cylinder? And what pressure do I pump it up to? And can speed bleeders be used with a pressure bleeder?
Questions about the pressure bleeder:
Is there a chance of fluid leaking out from under the cap that covers the master cylinder? And what pressure do I pump it up to? And can speed bleeders be used with a pressure bleeder?
Last edited by Ooglie Googlie; Mar 27, 2010 at 05:28 PM.
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
And what pressure do I pump it up to?
And can speed bleeders be used with a pressure bleeder?
Thread Starter
Intermediate
Joined: Nov 2008
Posts: 38
Likes: 0
From: New Jersey
Update on brake situation.
Wanted to update everyone on the brake situation. Got the master cylinder installed, bled the brakes and had a good pedal. After driving the car for a few miles pedal went to floor again.
Now, did some research and I have checked the m/c by plugging the lines going out to the brakes. Actually only plugged rear opening from m/c because the other plug I purchased didnt fit. But the plug for the rear brake line did fit. So, with rear brake opening plugged AND front brake line attached the pedal was high and tight. Started the car just to see if the power booster was fooling me. Still high and tight.
So it appears that I have isolated the problem to the rear brakes. Tonight, I am going to check the rear disc runout. This is because when I was reading up on the problem, it appears that the pistons in the rear calipers can suck air if the discs are wobbling in the caliper.
Also, does anyone think that this might be an issue with the proportioning valve?
Thanks. I just want to resolve this issue once and for all.
Now, did some research and I have checked the m/c by plugging the lines going out to the brakes. Actually only plugged rear opening from m/c because the other plug I purchased didnt fit. But the plug for the rear brake line did fit. So, with rear brake opening plugged AND front brake line attached the pedal was high and tight. Started the car just to see if the power booster was fooling me. Still high and tight.
So it appears that I have isolated the problem to the rear brakes. Tonight, I am going to check the rear disc runout. This is because when I was reading up on the problem, it appears that the pistons in the rear calipers can suck air if the discs are wobbling in the caliper.
Also, does anyone think that this might be an issue with the proportioning valve?
Thanks. I just want to resolve this issue once and for all.
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Race Director
Joined: Feb 2006
Posts: 12,239
Likes: 19
From: Chino CA
Race Director
Joined: Feb 2006
Posts: 12,239
Likes: 19
From: Chino CA
Wanted to update everyone on the brake situation. Got the master cylinder installed, bled the brakes and had a good pedal. After driving the car for a few miles pedal went to floor again.
Now, did some research and I have checked the m/c by plugging the lines going out to the brakes. Actually only plugged rear opening from m/c because the other plug I purchased didnt fit. But the plug for the rear brake line did fit. So, with rear brake opening plugged AND front brake line attached the pedal was high and tight. Started the car just to see if the power booster was fooling me. Still high and tight.
So it appears that I have isolated the problem to the rear brakes. Tonight, I am going to check the rear disc runout. This is because when I was reading up on the problem, it appears that the pistons in the rear calipers can suck air if the discs are wobbling in the caliper.
Also, does anyone think that this might be an issue with the proportioning valve?
Thanks. I just want to resolve this issue once and for all.
Now, did some research and I have checked the m/c by plugging the lines going out to the brakes. Actually only plugged rear opening from m/c because the other plug I purchased didnt fit. But the plug for the rear brake line did fit. So, with rear brake opening plugged AND front brake line attached the pedal was high and tight. Started the car just to see if the power booster was fooling me. Still high and tight.
So it appears that I have isolated the problem to the rear brakes. Tonight, I am going to check the rear disc runout. This is because when I was reading up on the problem, it appears that the pistons in the rear calipers can suck air if the discs are wobbling in the caliper.
Also, does anyone think that this might be an issue with the proportioning valve?
Thanks. I just want to resolve this issue once and for all.
Keep at it....my C3 brakes kick butt now....took a while - but now they rock...(all stock)
Thread Starter
Intermediate
Joined: Nov 2008
Posts: 38
Likes: 0
From: New Jersey
Im going to check the runout tonight.
Race Director
Joined: May 2003
Posts: 10,956
Likes: 409
From: California
well, i finally fixed mine once and for all... i replaced EVERYTHING but the hard lines... Willwood M/C, Hydro boost, 4 new calipers, SS lines... and 20 years of crappy brakes..... but they are now finally fixed!
Good luck....
Good luck....
Race Director
Joined: Feb 2006
Posts: 12,239
Likes: 19
From: Chino CA
You master your C3 brakes....and you can do ANY brakes..!
Keep us posted...you might learn something we don't know yet !
Thread Starter
Intermediate
Joined: Nov 2008
Posts: 38
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From: New Jersey
When I was younger I drove older cars as my primary car. One car, a 1969 camaro, had a problem with the transmission. It was an m-20. For some reason it would get stuck in both 1st gear and reverse. Ive taken that tranny out and put it back in so many times that I could of did it in my sleep. But I needed the car to get to work the next day so I was forced to do it.
Actually I should of been an auto mechanic. I was when I was 20 years old. But when I put a torch to a exhaust pipe on an old nova that had a carb that was dumping fuel (didnt know this) plans changed.
Race Director
Joined: Feb 2006
Posts: 12,239
Likes: 19
From: Chino CA
I think .006" is a little high.....get yerself some lug-stud shims (they look like little THIN washers) and try to shim the rotor until you can't get it any better - then try a little more (LOL !).
The only other idea I have is getting O-ring style calipers. The lip seal style (factory) tend to pump air MUCH more than the O-ring style...
Try shimming.....cheaper !
The only other idea I have is getting O-ring style calipers. The lip seal style (factory) tend to pump air MUCH more than the O-ring style...
Try shimming.....cheaper !
Thread Starter
Intermediate
Joined: Nov 2008
Posts: 38
Likes: 0
From: New Jersey
Ok. Pulled the calipers off today to acess the rotors which I think are stuck. Left caliper seems to be weeping fluid around pistons. Rubber seal around piston is wet with fluid. Left caliper is dry.
Unfortunately, at this time I cannot afford to purchase new or rebuilt calipers. Would it be possible to rebuild them? Is it difficult?
Thanks!!
Unfortunately, at this time I cannot afford to purchase new or rebuilt calipers. Would it be possible to rebuild them? Is it difficult?
Thanks!!
