Brake Bleeding - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cst350 · 12-09-2013, 05:09 PM

I have read as many threads as I could find on this. Unfortunately there is a lot of conflicting info about the proportioning valve and the sequence of which corner to start with.

My truck is a 69 but upgraded to disc front and drum rear, all new parts. I only have the service manual for the 69 (all drum) so it is not helping much. I have bench bled the new master and the proportioning valve I have has a pin that can be pulled out but not compressed. Should I shim the pin so it is all the way out and do all four corners starting at the passenger rear?

And, I have a vacuum pump. Do I need to depress the pedal before I use the pump?

Thanks for any help

HotRod C/10 · 12-09-2013, 07:15 PM

http://www.dummies.com/how-to/conten...ur-brakes.html

cst350 · 12-09-2013, 07:52 PM

Hot Rod_c_10

Thanks for the link, unfortunately it does not cover information about the proportioning valve pin or the conflicting information other threads have about starting in the front or at the rear.

HotRod C/10 · 12-09-2013, 08:00 PM

type bleeding brakes into the google link at the top of this page and dot the 67-72chevytrucks.com button.......it should give you a wealth of info on this site.

geezer#99 · 12-09-2013, 08:04 PM

The pin needs to be held in. Then bleed from the furthest wheel cylinder to the closest.
Did you bench bleed the master cylinder before installing it?

cst350 · 12-09-2013, 08:41 PM

Geezer 99

Thanks for the direct answer... I did bleed the MC but thought the proportioning valve pin needed to be compressed (which it cant), sounds like it just needs to be held in place so it doesn't extend.

Hot Rod C_10

Spent the afternoon reading all of the threads from our message board. Thats why it became sooooo confusing. Thanks for the reply though.

12-09-2013, 05:09 PM	#1
cst350 Registered User Join Date: Dec 2003 Location: nor cal Posts: 218	Brake Bleeding I have read as many threads as I could find on this. Unfortunately there is a lot of conflicting info about the proportioning valve and the sequence of which corner to start with. My truck is a 69 but upgraded to disc front and drum rear, all new parts. I only have the service manual for the 69 (all drum) so it is not helping much. I have bench bled the new master and the proportioning valve I have has a pin that can be pulled out but not compressed. Should I shim the pin so it is all the way out and do all four corners starting at the passenger rear? And, I have a vacuum pump. Do I need to depress the pedal before I use the pump? Thanks for any help

12-09-2013, 07:15 PM	#2
HotRod C/10 Registered User Join Date: Feb 2012 Location: Albuquerque NM Posts: 3,053	Re: Brake Bleeding http://www.dummies.com/how-to/conten...ur-brakes.html __________________ SOLD -77 CHEYENNE SWB, LS SWAPPED -1976 SILVERADO YUBA GOLD/NEUTRAL (2-TONE)

12-09-2013, 07:52 PM	#3
cst350 Registered User Join Date: Dec 2003 Location: nor cal Posts: 218	Re: Brake Bleeding Hot Rod_c_10 Thanks for the link, unfortunately it does not cover information about the proportioning valve pin or the conflicting information other threads have about starting in the front or at the rear.

12-09-2013, 08:00 PM	#4
HotRod C/10 Registered User Join Date: Feb 2012 Location: Albuquerque NM Posts: 3,053	Re: Brake Bleeding type bleeding brakes into the google link at the top of this page and dot the 67-72chevytrucks.com button.......it should give you a wealth of info on this site. __________________ SOLD -77 CHEYENNE SWB, LS SWAPPED -1976 SILVERADO YUBA GOLD/NEUTRAL (2-TONE)

12-09-2013, 08:04 PM	#5
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,531	Re: Brake Bleeding The pin needs to be held in. Then bleed from the furthest wheel cylinder to the closest. Did you bench bleed the master cylinder before installing it?

12-09-2013, 08:41 PM	#6
cst350 Registered User Join Date: Dec 2003 Location: nor cal Posts: 218	Re: Brake Bleeding Geezer 99 Thanks for the direct answer... I did bleed the MC but thought the proportioning valve pin needed to be compressed (which it cant), sounds like it just needs to be held in place so it doesn't extend. Hot Rod C_10 Spent the afternoon reading all of the threads from our message board. Thats why it became sooooo confusing. Thanks for the reply though.



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