need brake system help!
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I couldn't find an old distribution block in the shop but I am looking at a cutaway of the block in a Chevy manual and all 3 front lines come together around the spring at the end on the internal piston so I don't see anyway for the piston to block off the flow of fluid.
Melting Slicks
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
I couldn't find an old distribution block in the shop but I am looking at a cutaway of the block in a Chevy manual and all 3 front lines come together around the spring at the end on the internal piston so I don't see anyway for the piston to block off the flow of fluid.
I guess it depends on what he has in there. But I can't see both fronts being dry though because of another machanical failure, maybe one side but not both.
The instruction I posted came out of the repair manual. I guess they could be wrong. Its hard to tell with these books that group a number of model years together.
Here is a good read.http://www.piratejack.net/Tech-Suppo...ng-Valves.html
To me it sounds like a proportioning valve problem. He will have to figure that out.
Jim
Thread Starter
Intermediate
Joined: May 2009
Posts: 37
Likes: 0
From: Leland NC
The valve I have is a brand new one purchased from ecklers. Personally I think they are using the commonly missed used term "portioning" valve. But I do believe it does have the ability to stop the flow of fluid. By manually pouring fluid into the lines with a funnel and a few small hoses, I can get fluid flowing perfectly from the line that connects to the valve all the way down to the caliper. I can also use my hand pump vacuum to pull fluid from the MC to the lines before the valve. I cannot pull fluid after the valve for the fronts. Currently my plan of action is to continue filling the lines manually and then going from there. Hopefully, w/ some fluid in the lines, I can then stump on the pedal, reset the switch, and bleed as normal.
P.S. - no need to worry about paint, the car needs a paint job and lots of sanding anyways
P.S. - no need to worry about paint, the car needs a paint job and lots of sanding anyways
Advanced
Joined: Sep 2009
Posts: 57
Likes: 0
From: Jacksonville FL
ok so check it out, my brake light was on for a while(im talking a few months) i just thought my E-handle switch shorted keeping the brake light on. my right rear tire blew out i replaced it. the next day i looked around to see if the blow out did any real damage. i noticed my tire was a little wet. so i looked in my MC and the back was empty!! i took off the tire to find no obvious leaking point. i put new fluid in thinking i would find the leak easy. well i couldnt get any fluid to get back there, until i read this post and learned about the brake light and the portioning valve (combination valve for my '76). so what i did was crack open my front bleeder (one side) and tapped the valve with a rubber mallet and that did the trick for me. the valve returned to the middle and fluid went to the back and i found my leak. but my brake light is still on. hoping it goes off once i fix the leak and bleed the system. maybe it is just a short!?!?
Melting Slicks
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
ok so check it out, my brake light was on for a while(im talking a few months) i just thought my E-handle switch shorted keeping the brake light on. my right rear tire blew out i replaced it. the next day i looked around to see if the blow out did any real damage. i noticed my tire was a little wet. so i looked in my MC and the back was empty!! i took off the tire to find no obvious leaking point. i put new fluid in thinking i would find the leak easy. well i couldnt get any fluid to get back there, until i read this post and learned about the brake light and the portioning valve (combination valve for my '76). so what i did was crack open my front bleeder (one side) and tapped the valve with a rubber mallet and that did the trick for me. the valve returned to the middle and fluid went to the back and i found my leak. but my brake light is still on. hoping it goes off once i fix the leak and bleed the system. maybe it is just a short!?!?
Jim
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Chris did you get this fixed yet ?
Here are a couple pics from a 73 GM manual showing a cutaway of the distribution valve. This valve is in the forward position like yours. If you look at the cutaway all front lines come in around the spring,I dont see anyway the piston can block flow.
Here are a couple pics from a 73 GM manual showing a cutaway of the distribution valve. This valve is in the forward position like yours. If you look at the cutaway all front lines come in around the spring,I dont see anyway the piston can block flow.
Last edited by ...Roger...; Sep 21, 2009 at 08:51 AM.
Advanced
Joined: Sep 2009
Posts: 57
Likes: 0
From: Jacksonville FL
well i finally fixed my leak and bleed out the system Took so long cuz my wife just had out 2st boy on the 21st!!!) anyway the light did go out so it wasnt a short and im thinking the brake fluid caused my tire to blow cuz my tire looks good for the most part and the highway was clean and smoth not sure what made it blow out. hahahaha my high school english teacher would be pissed at my run-on sentence. 
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