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-   -   Need quick help with new prop valve (https://67-72chevytrucks.com/vboard/showthread.php?t=298253)

byrd 07-05-2008 01:17 PM

Need quick help with new prop valve
 
I installed a new booster, M/C and disc drum prop vavle from Brothers when I changed over to discs in the front. I also replaced all the lines and hoses in the system at the same time. I am getting fluid out of the front lines but not the rear. I have tried to vacuum pump the rear in and still nothing.According to the directions the prop valve is off center, and to recenter it I am supposed to open the front since it has fluid flowing and have some one slowly depress the brake pedal, until the valve centers up. Well I have tried this method at least a half a dozen times and still nothing in the rears, and the valve is still off center. Is there another way of centering the valve? The is a little button or something on the front of the prop valve and it is under a little rubber cap, does anyone know if this has something to do with the not centering, I will get a pic uploaded shortly. I need to get the brakes working right before the end of the weekend and get the truck up on my trailer to go to the alignment shop first thing Monday. Any help will be GREATLY APPRECIATED....Randy

LONGHAIR 07-05-2008 01:53 PM

Re: Need quick help with new prop valve
 
You have to push the pedal more than half way. Usually it takes a full stroke to the bottom, you will feel a click in most cases. Sometimes it takes a few strokes. Yes it will suck air into the fronts....that is what is balancing the pressure.
Personally I prefer "gravity bleeding" in a case like this. Once you get the valve centered, open all of the bleeders and let the fluid flow. Sometimes it takes a while to get going, be patient. Leave the cap off of the master cylinder and keep an eye on the fluid level. Don't let it get too low. Do not touch the pedal at all during this. After is runs for a while, just close the bleeders and you should be good to go. It sounds too simple...but it does work. It also gives you the opportunity to flush any old fluid that was is the lines.

dwcsr 07-05-2008 03:41 PM

Re: Need quick help with new prop valve
 
I had the same issue with mine. I removed the rear line from the prop valve and pushed the valve forward to center it. I made a centering tool to hold the prop valve in place and used speed bleeders and was done it 20 minutes .

It had taken me all one day and most of the next trying to bleed it without the tool and speed bleeders.

byrd 07-05-2008 09:09 PM

Re: Need quick help with new prop valve
 
Not sure what a speed bleeder is??

I will give your idea a shot as I am done trying to get it to center the other way. I am totally pissed at this piece of crap... Please advise on the speed bleeders ....Randy

fastom 07-05-2008 09:37 PM

Re: Need quick help with new prop valve
 
Try this for your speed bleeder. http://store.summitracing.com/partde...5&autoview=sku

c10crazy 07-05-2008 11:00 PM

Re: Need quick help with new prop valve
 
Turn the key to the ON position but do not start the truck. This will light up the red brake light in the dash. Now stomp on the brake pedal one time as hard and fast as you can! You should see the light go out because it will now be centered! Works every time!;)

70GMCer 07-06-2008 07:43 AM

Re: Need quick help with new prop valve
 
:agree: That worked for 70c10. He also had the same problem until he stomped down hard on the pedal.......

LONGHAIR 07-06-2008 08:07 AM

Re: Need quick help with new prop valve
 
That can work...........but it is definately not an "every time" thing.

va_tlc 07-06-2008 10:02 PM

Re: Need quick help with new prop valve
 
for some odd reason i get a giggle outa STOMPIN the pedal, well glad i read this cause my light wont go off, so now im off to do some stompin, but first i have to replace my m/c its leaking inbetween the m/c and booster, but it wasnt before i done all my brakes . weired huh

Sammy 07-06-2008 10:20 PM

Re: Need quick help with new prop valve
 
I had good luck with the stomp method too.


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