Quote:
Originally Posted by PHAT TONY
I'd take the tape off the bleeders to start; they bottom out to seal. You need to keep the pin in the end of the prop valve from moving while bleeding; it may want to push out. If you have a vaccum pump they work great to suck fluid to the rear to start the process; I think you have air in the line to the back and its jerking you around going from side to side as you bleed. This has got me twice! I used a cheapy hand pump to draw fluid first to the passenger rear, then drivers (make sure system is sealed at the 3 other brakes). Once the line is free of air, and you're sure the prop valve stays centered, they'll bleed out quick.
My Blazer didn't have enough brake to stop the rear wheels in drive at idle on jack stands! Seems like I used 35 gallons of fluid and still had air in back; it took a while with the hand pump but I eventually got some BIG bubbles that must've been moving back and forth. I went through the SAME thing on a customers '68 GMC too.
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Phat Tony,
Thanks for your comment on bleeding brakes. It helped me.
What I was observing after replacing the rear braking system:
- Pedal would go to the floor, and brake light would turn on.
- Pumping the brake a few times gave me working brakes, and the light would turn off (I'm assuming the piston inside that sensor would recenter once I got pressure on each side.)
What I was doing:
- Bleeding the brake system like crazy. Mostly in the back, but also at the master cylinder and the front calipers too.
- I was observing foamy air bubbles in the back. It seemed worse on the passenger side.
What I did:
I almost gave up, and drove it to a shop in town that I think is decent, but I tried your recommendation of using a vacuum pump to bleed the system.
I bled out a full cup of fluid from both rear cylinders at the bleeding nipples, and I had good brakes. What a relief.
I'm never going to bleed brakes again without using one of these vacuum pumps. I also really like that I don't have to get a second person involved to do this.
Thanks again,
JP