Problem gravity bleeding brakes with new prop valve - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**NC67Chev** · 08-02-2014, 01:32 PM

Trying to put the finishing touches on disc brake conversion today. I'm trying to get the brakes gravity bled, but I can't get any fluid to move at all with the bleeders wide open. I've seen something referring to this button on the front of the prop valve. Do I have to do something with it while I'm gravity bleeding?

*JonnyC10* · 08-02-2014, 02:04 PM

Is that line on the rear of the prop valve kinked? Sure looks it. That's probably your problem.

**NC67Chev** · 08-02-2014, 02:15 PM

Quote:

Originally Posted by JonnyC10

Is that line on the rear of the prop valve kinked? Sure looks it. That's probably your problem.

No kinked lines

*JonnyC10* · 08-02-2014, 02:26 PM

Did you bench bleed the MC?

**NC67Chev** · 08-02-2014, 03:49 PM

Quote:

Originally Posted by JonnyC10

Did you bench bleed the MC?

Yes, I bench bled the MC. I had my wife hold the pedal down while a cracked the bleeder valve a couple of times and its bleeding fine now.

*Fitz* · 08-02-2014, 04:27 PM

Quote:

Originally Posted by NC67Chev

Trying to put the finishing touches on disc brake conversion today. I'm trying to get the brakes gravity bled, but I can't get any fluid to move at all with the bleeders wide open. I've seen something referring to this button on the front of the prop valve. Do I have to do something with it while I'm gravity bleeding?

On the type of prop /combination valve you have, depressing and holding the button nearest the front brake line should allow your brakes to bleed. There is a piston inside your valve that probably needs to be re-centered. If depressing and holding the front button does not work then it gets a bit more complicated. The piston can be centered by removing the 9/16 in rear cap and pressing the piston all of the way forward. Remove the plastic brake switch contact and use a pick to center the V slot in the piston in the center of the switch port. Re-insert the switch. If it reads "open" with a circuit tester or infinite resistance with an ohm meter it is in the correct location and your brakes will gravity bleed. At this point I usually insert a "centering tool" which holds that piston immobile while you continue bleeding. Performance On Line has one for $ 7.00. It screws into the warning switch port. Be sure to replace the warning switch when you are finished. Good luck

08-02-2014, 01:32 PM	#1
NC67Chev Senior Member Join Date: Oct 2009 Location: Greensboro, NC Posts: 698	Problem gravity bleeding brakes with new prop valve Trying to put the finishing touches on disc brake conversion today. I'm trying to get the brakes gravity bled, but I can't get any fluid to move at all with the bleeders wide open. I've seen something referring to this button on the front of the prop valve. Do I have to do something with it while I'm gravity bleeding? Attached Images __________________ 1967 Chevy C-10, 250 L6, Powerglide, 3.73, SWB, Fleetside Upgrades: Power steering, Offset air cleaner, Rear Sport bumper, 3 point safety belts, HEI, -1/-2 springs, 16x5 wheels, McGaughy's disc brake conversion, Sway bar

08-02-2014, 02:04 PM	#2
JonnyC10 Account Suspended Join Date: Jul 2014 Location: NH Posts: 280	Re: Problem gravity bleeding brakes with new prop valve Is that line on the rear of the prop valve kinked? Sure looks it. That's probably your problem.

08-02-2014, 02:26 PM	#4
JonnyC10 Account Suspended Join Date: Jul 2014 Location: NH Posts: 280	Re: Problem gravity bleeding brakes with new prop valve Did you bench bleed the MC?



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