no brake pedal pressure. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

70-Chevy · 03-31-2007, 01:24 PM

Alright,
I recently replaced every bit of brake hardware I could buy/find. I replaced drums, lines, wheel cylinders, pads, hardware, m/c, etc. I had really good brakes for quite a while until my headers burnt a pinhole in one of my lines after the clip broke from the chassis that holds it. Well, I replaced that line, and hooked it all back up. I bought a brand new m/c and bench bled it and bled all four wheels in the correct order with a one-man hand held vacuum pump. i got good, clean, solid, and clear fluid throughout all four wheel cylinders and I have absolutley no brake pedal at all. The pedal goes to the floor. Is there any ideas you gentleman have for me?

Also, can a proportioning vavle go bad and if it can, what could be some signs?

Thank you for all the help in advance gentleman.

Chris

70-Chevy · 03-31-2007, 01:44 PM

Anyone have any ideas?

**PICKMUP** · 03-31-2007, 02:58 PM

It sounds like you have air in the lines.
I also have a good vacuum pump brake bleeder, and sometimes I just don't trust it.
Try bleeding the brakes with the old two-person style...have someone in the cab pumping them up as you bleed.
Let us know how this turns out.

centsless · 03-31-2007, 06:15 PM

Also, If it was driven with the hole in the line, the proportioning valve may be stuck to one side. You will need to bleed them manually with two people. If you dont get any pressure out of the fronts ( I assume that is where the hole was ) , then the valve is stuck. With all of the bleeders closed, abruptly kick the brake pedal. Sometimes you have to repeat this several times to get it to work. Another way is to open a rear bleeder and quickly depress the brake pedal. The loss of pressure in the rear will force the valve the other way. Hope that helps!

1LoC10 · 03-31-2007, 06:20 PM

take the cover off the MC and have someone keep pumping the brakes till the bubbling stops, it should get pressure after awhile of pumping... worth a try.. ive done it in the past

70-Chevy · 03-31-2007, 08:27 PM

gentleman, thank you for all of your ideas, Ill be sure to try them all and post on the outcome. Thanks,

Chris

03-31-2007, 01:24 PM	#1
70-Chevy -Chris Join Date: Sep 2002 Location: Moyock, NC Posts: 622	no brake pedal pressure. Alright, I recently replaced every bit of brake hardware I could buy/find. I replaced drums, lines, wheel cylinders, pads, hardware, m/c, etc. I had really good brakes for quite a while until my headers burnt a pinhole in one of my lines after the clip broke from the chassis that holds it. Well, I replaced that line, and hooked it all back up. I bought a brand new m/c and bench bled it and bled all four wheels in the correct order with a one-man hand held vacuum pump. i got good, clean, solid, and clear fluid throughout all four wheel cylinders and I have absolutley no brake pedal at all. The pedal goes to the floor. Is there any ideas you gentleman have for me? Also, can a proportioning vavle go bad and if it can, what could be some signs? Thank you for all the help in advance gentleman. Chris __________________ 1970 Chevy C-10 P/U, Shortbed, Fleetside - 5/7 drop, 496, TH400, 12 bolt. BUILD THREAD - http://67-72chevytrucks.com/vboard/s...d.php?t=404481 2012 F250 Super Duty P/U - intake, exhaust, tuner, 4" lift with 35's 2017 Chevy Suburban (Wifes Car) - Fully Loaded & Stock "Some people spend an entire lifetime wondering if they made a difference in the world. But, the Marines don't have that problem." Ronald Reagan, President of the United States; 1985

03-31-2007, 01:44 PM	#2
70-Chevy -Chris Join Date: Sep 2002 Location: Moyock, NC Posts: 622	Re: no brake pedal pressure. Anyone have any ideas? __________________ 1970 Chevy C-10 P/U, Shortbed, Fleetside - 5/7 drop, 496, TH400, 12 bolt. BUILD THREAD - http://67-72chevytrucks.com/vboard/s...d.php?t=404481 2012 F250 Super Duty P/U - intake, exhaust, tuner, 4" lift with 35's 2017 Chevy Suburban (Wifes Car) - Fully Loaded & Stock "Some people spend an entire lifetime wondering if they made a difference in the world. But, the Marines don't have that problem." Ronald Reagan, President of the United States; 1985

03-31-2007, 02:58 PM	#3
PICKMUP "Trucks with Class" Join Date: Jul 2000 Location: OLYMPIA, WA, USA Posts: 8,158	Re: no brake pedal pressure. It sounds like you have air in the lines. I also have a good vacuum pump brake bleeder, and sometimes I just don't trust it. Try bleeding the brakes with the old two-person style...have someone in the cab pumping them up as you bleed. Let us know how this turns out.

03-31-2007, 06:15 PM	#4
centsless sufficiently talented fool Join Date: Jun 2006 Location: Forest Hill, MD Posts: 2,231	Re: no brake pedal pressure. Also, If it was driven with the hole in the line, the proportioning valve may be stuck to one side. You will need to bleed them manually with two people. If you dont get any pressure out of the fronts ( I assume that is where the hole was ) , then the valve is stuck. With all of the bleeders closed, abruptly kick the brake pedal. Sometimes you have to repeat this several times to get it to work. Another way is to open a rear bleeder and quickly depress the brake pedal. The loss of pressure in the rear will force the valve the other way. Hope that helps! __________________ "it's impossible to be surrounded by idiots when you are part of the circle" 2003 Suburban 2002 Pontiac Montana 1981 Corvette 1966 Impala Convertible Click here to support the board

03-31-2007, 06:20 PM	#5
1LoC10 Insert Title Here Join Date: Feb 2006 Location: Dyer, Indiana Posts: 5,679	Re: no brake pedal pressure. take the cover off the MC and have someone keep pumping the brakes till the bubbling stops, it should get pressure after awhile of pumping... worth a try.. ive done it in the past __________________ BOBBY _69 SWB_ 1000 pics of 67-72's>> http://s193.photobucket.com/albums/z...-72/?start=all <<

03-31-2007, 08:27 PM	#6
70-Chevy -Chris Join Date: Sep 2002 Location: Moyock, NC Posts: 622	Re: no brake pedal pressure. gentleman, thank you for all of your ideas, Ill be sure to try them all and post on the outcome. Thanks, Chris __________________ 1970 Chevy C-10 P/U, Shortbed, Fleetside - 5/7 drop, 496, TH400, 12 bolt. BUILD THREAD - http://67-72chevytrucks.com/vboard/s...d.php?t=404481 2012 F250 Super Duty P/U - intake, exhaust, tuner, 4" lift with 35's 2017 Chevy Suburban (Wifes Car) - Fully Loaded & Stock "Some people spend an entire lifetime wondering if they made a difference in the world. But, the Marines don't have that problem." Ronald Reagan, President of the United States; 1985



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