Author Topic: 1969 Brake issues  (Read 4331 times)

1969SS350

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1969 Brake issues
« on: June 21, 2009, 02:19:12 AM »
Greetings-
I am having some issues with my brakes.
I installed new brake lines-Master Cylinder-Booster-Proportioning valve-metering block, attempted to bleed the brakes and the pedal is permanently in the up position, no movement at all?
I bench bled the MC and am unsure where to go from here?

Any suggestions?

Charles

JohnZ

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Re: 1969 Brake issues
« Reply #1 on: June 21, 2009, 02:42:09 PM »
Do you have the clevis in the lower hole in the pedal arm? The upper hole is only for manual brakes.
'69 Z/28
Fathom Green
CRG

1969SS350

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Re: 1969 Brake issues
« Reply #2 on: June 21, 2009, 03:09:03 PM »
Thank you for the post.
I double checked the Clevis and it is in the lower hole in the pedal arm.
How far should the clevis be adjusted?

Any other ideas?

Charles

Sauron327

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Re: 1969 Brake issues
« Reply #3 on: June 21, 2009, 06:14:01 PM »
Is the booster to master cylinder rod the correct length? Try loosening the MC from the booster and see if you get any pedal play. If it's rock hard like you say something is askew between the pedal and MC. Your description sounds like the MC piston is being buried.

1969SS350

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Re: 1969 Brake issues
« Reply #4 on: June 21, 2009, 07:27:37 PM »
Is the booster to master cylinder rod the correct length? Try loosening the MC from the booster and see if you get any pedal play. If it's rock hard like you say something is askew between the pedal and MC. Your description sounds like the MC piston is being buried.

MC was loosened and the pedal moves-appears the rod is not the correct length,what length should the rod be?

Charles

Sauron327

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Re: 1969 Brake issues
« Reply #5 on: June 21, 2009, 10:22:33 PM »
Compare the old MC to the new one and see if the piston locations in the back are the same. Is this a conversion kit you are installing by any chance? Like I said, something is amiss. Obviously right?.

1969SS350

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Re: 1969 Brake issues
« Reply #6 on: June 21, 2009, 10:47:57 PM »
locations the same and this is a replacement Delco Moraine Booster and MC from firewheel classics.
The original MC was not the right one and the P Valve was missing, everything worked good though.
it has original front disc and rear drum.

Sauron327

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Re: 1969 Brake issues
« Reply #7 on: June 22, 2009, 02:18:33 AM »
I have to ask again. Is the piston on the back of the MC flush or recessed? Are the old and the new the same in this aspect? Flush gets short rod, recessed gets long rod. If the system worked before as you say something is assembled incorrectly or the parts are wrong which is binding/holding the pedal in the up position. It sounds as if the rod is too long and when you tighten the MC to the PB it's burying the piston in the MC.

1969SS350

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Re: 1969 Brake issues
« Reply #8 on: June 22, 2009, 03:09:17 AM »
Piston is flush.
I cant compare the old with the new because its gone........

the rod that is in it is 4", how long is the short rod compared to the long rod?
and where can i purchase the short rod from?

Thanks for your patience

Charles

Sauron327

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Re: 1969 Brake issues
« Reply #9 on: June 22, 2009, 10:46:35 AM »
How far does the rod you have now stick out of the back of the MC? Here's a link that may help you. http://www.pozziracing.com/brakes.htm#Booster

The vendors have the rod you need or you can cut it.

1969SS350

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Re: 1969 Brake issues
« Reply #10 on: June 22, 2009, 02:03:01 PM »
I pulled the pushrod out and measured it it is 4"
I think we found the problem.......Thank you


Ill get the 2 5/8 " pushrod today!

Thanks again

Charles

1969SS350

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Re: 1969 Brake issues
« Reply #11 on: June 26, 2009, 11:15:28 PM »
okay so ive replaced the pushrod and attempted to bleed the brakes-the front were fine and I cant get anything out of the back brake lines?
what next?

Steve68

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Re: 1969 Brake issues
« Reply #12 on: June 27, 2009, 09:38:24 PM »

Sauron327

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Re: 1969 Brake issues
« Reply #13 on: June 27, 2009, 10:19:43 PM »
He's all set, he's double posting the same issue in maintenance under different subject titles.