Bleeding brakes, no fluid to the rears - The 1947 - Present Chevrolet & GMC Truck Message Board Network

19GMC63 · 02-24-2007, 08:05 PM

Ok, so yesterday I replaced a rear brake line since the PO snipped the old rusty one off because it had a hole in it. When I took the old one off, I got a dribble of fluid.
Well, I filled the rear reservoir, and began to bleed the rear brakes, and got nothing, no air or fluid. I tried pressure bleeding and the traditional two man bleeding and the bleeders are clean. I tried holding the metering pin in on the prop. valve with no luck, still no fluid to the rear.
Oh, and the front brakes (discs) work fine.

I'm stumped.

thanks in advance for the help/

I also posted this in the general forum to get more opinions.

wild one · 02-24-2007, 09:15 PM

I had the same problem when recently when I re-did my brakes. Fist thing to do is remove the hard brake lines from the wheel cylinders, then remove the hard line for the rear from the brake line splitter Tee ( stock set-up, four wheel drum and single reservoir master cylinder ), or if you have a dual reservoir master cylinder then remove the rear brake line from the proportioning valve.

Then put pressurized air to the inlet side of the rear hard line ( I have my compressor set to supply 120 psi ) and let 'er rip. I had all kinds of crap blow out of my lines, so make sure that there is clear open space on either side of the truck so you do not blast all of the crud onto anything or anyone that you care about.

I then replaced my wheel cylinders, re-attached my brake lines and bled them with a mitey-vac vacuum pump, making sure to completely flush the system with fresh brake fluid. It took a little longer than usual but worked great and allowed me to perform the brake job by myself.

glennhuff · 02-24-2007, 10:13 PM

It's also helpful to bleed the master cylinder before you try to bleed the lines. If the master cylinder full of air, you will never get fluid through the lines. Take the rear line loose from the master cylinder, and put a short piece of brake line in and then pump the master cylinder until you get all of the air out. Then hook the rear line back up.

Glenn

thekid54 · 02-26-2007, 05:17 PM

I had the same problem on my '62. The rear rubber line was clogged. I couldn't even blow 150psi air through it! Replaced the line and never had a problem again.

02-24-2007, 08:05 PM	#1
19GMC63 Registered User Join Date: Nov 2006 Location: Nashville, TN Posts: 1,510	Bleeding brakes, no fluid to the rears Ok, so yesterday I replaced a rear brake line since the PO snipped the old rusty one off because it had a hole in it. When I took the old one off, I got a dribble of fluid. Well, I filled the rear reservoir, and began to bleed the rear brakes, and got nothing, no air or fluid. I tried pressure bleeding and the traditional two man bleeding and the bleeders are clean. I tried holding the metering pin in on the prop. valve with no luck, still no fluid to the rear. Oh, and the front brakes (discs) work fine. I'm stumped. thanks in advance for the help/ I also posted this in the general forum to get more opinions.

02-24-2007, 09:15 PM	#2
wild one Registered......... Join Date: May 2006 Location: Livermore,CA Posts: 288	Re: Bleeding brakes, no fluid to the rears I had the same problem when recently when I re-did my brakes. Fist thing to do is remove the hard brake lines from the wheel cylinders, then remove the hard line for the rear from the brake line splitter Tee ( stock set-up, four wheel drum and single reservoir master cylinder ), or if you have a dual reservoir master cylinder then remove the rear brake line from the proportioning valve. Then put pressurized air to the inlet side of the rear hard line ( I have my compressor set to supply 120 psi ) and let 'er rip. I had all kinds of crap blow out of my lines, so make sure that there is clear open space on either side of the truck so you do not blast all of the crud onto anything or anyone that you care about. I then replaced my wheel cylinders, re-attached my brake lines and bled them with a mitey-vac vacuum pump, making sure to completely flush the system with fresh brake fluid. It took a little longer than usual but worked great and allowed me to perform the brake job by myself. __________________ 1966 C10 panel-400 small block/TH 350 combo Nothing is fool proof to a talented fool! Popcorn: Pops at exactly 444 degreese Expands to 44 times it's original size Has a 4 year shelf life

02-24-2007, 10:13 PM	#3
glennhuff Registered User Join Date: Oct 2003 Location: Myrtle Point Oregon Posts: 24	Re: Bleeding brakes, no fluid to the rears It's also helpful to bleed the master cylinder before you try to bleed the lines. If the master cylinder full of air, you will never get fluid through the lines. Take the rear line loose from the master cylinder, and put a short piece of brake line in and then pump the master cylinder until you get all of the air out. Then hook the rear line back up. Glenn

02-26-2007, 05:17 PM	#4
thekid54 Registered User Join Date: Jan 2006 Location: LA, CA Posts: 296	Re: Bleeding brakes, no fluid to the rears I had the same problem on my '62. The rear rubber line was clogged. I couldn't even blow 150psi air through it! Replaced the line and never had a problem again.



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