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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 22715
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
MC lid ON...unless you like cleaning brake fluid off of everything under the hood....
So....if you disconnect the line directly from the MC itself and blow thru it, you get flow to the rear??? This is before the P valve, so if that is correct, then the P valve HAS to be centered....there would be NO flow if it weren't. That can mean only one thing...the Master is faulty.
Try this, if possible. SWAP the lines on the MC, and see if you get fluid to the rear...if you do, then the master is definitely the problem. I say "if possible" because the fittings on the front/rear lines may be a different size, so you may not be able to do it, but it's definitely worth a try.

So....if you disconnect the line directly from the MC itself and blow thru it, you get flow to the rear??? This is before the P valve, so if that is correct, then the P valve HAS to be centered....there would be NO flow if it weren't. That can mean only one thing...the Master is faulty.
Try this, if possible. SWAP the lines on the MC, and see if you get fluid to the rear...if you do, then the master is definitely the problem. I say "if possible" because the fittings on the front/rear lines may be a different size, so you may not be able to do it, but it's definitely worth a try.
Joel Adams
C3VR Lifetime Member #56
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Joel, I will try switching lines . It is a new- reconditioned MC. But yes I get air to the rears by blowing air in upstream of the PV , From disconnected line at the MC fittings are same size
Thanks, AL
UPDATE NO FLOW FROM REAR MC unit.. Tried even to get anything out of the fitting .Like stepping on pedal and hoping for a squirt all over fender well. ANOTHING. Nada. Zilch . Funny when I bench bleed it , the hose ran full of fluid. Now nothing. . OH well what's another trip to the parts store. Will do tomorrow and let you know what happens .
AL
|UPDATED|7/24/2013 11:39:01 AM (AZT)|/UPDATED|
|UPDATED|7/24/2013 11:39:01 AM (AZT)|/UPDATED|

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apasbigal said: I replaced rotors,calipers , ebrake. First the fronts, then rears.After fronts were done al was well. Year later, I just did the rears, and e brake . Some how or when master cylinder when dry . Filled the mc ,pumped the brakes and watched bubbles come up into mc. Proceeded to try gravity, bleed Nothing , vacuum, some fluid came out of all four wheels but the stopped. Seems to me the amount that came out is about what should be in each line . Built a pressure bleeder , 20 psi - nothing
Could the proportioning valve/ switch be bad ?? Or the mc or both
Help I am fully baffled
Many thanks. Big Al
Probably a stupid question but was the cover off the MC when you tried gravity and vacuum bleed? It would stop bleeding when vacuum built up in MC with the cover on.


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DanT
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Cover off ,engine off and power brake check valve removed . My last post is returning MC as no flow is coming from rear compartment .
Frustrating , but a labor of love and hate. AL

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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 22715
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Well it sux you got a bad MC, but good that you got it figured out. Be sure to bench bleed the new one before installing it.

Joel Adams
C3VR Lifetime Member #56
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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Will do and I'll keep you posted. Tried to loosen the line on the PV But no luck or I'm weak
AL

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I replaced lines from MC to PV and couldn't get lines off PV even with a 6 point line wrench...Had to remove PV and clamp in vice and use vise grips on line to remove




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DanT
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UPDATE. Another new reconditioned MC, bench blend according to MFG suggestions. Installed. Gravity bled fronts all ok
Backs needed a little vacuum to get flow started . Then used pump and release to make sure alls well.
ALL ARE NOW BLED AND fluid at all bleeders and no bubbles. YES WE HAVE COMPLETED THE BRAKES
NEXT PROBLEM T /T. HORN .
THanks all
AL.

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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 22715
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas




Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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