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

vectorit · 10-22-2009, 10:14 PM

Hey all, I am getting my high tech four drum power drum brakes back in order, and I just got through bleeding out what I thought was all the air pockets.
With the truck not running I pumped and bled out each wheel, in the process the manual says too. Things were coming along great, got good pedal and thought this was too easy. Until I fired up the engine, and then pressed down on the brake pedal. Just as I expected, the pedal went straight to the floor. It did not come back up, and only has about an inch worth of travel.

It's dark out now, and my lighting isn't all that great. So I will pick this up tomorow.

Just wondering should I do this while there is vacuum to the booster? Or do I just start the process all over again then repeat, then run the engine to see if the pedal normalizes in it's travel and resistance?

Fogive the basic question, it's just been years since I did this. Plus I am all by myself, in the past I had a buddy pump the brakes while I cracked the wheel cylinder bleed valve.

Right now I am using a jar and rubber hose to catch all the dirty fluids.

Gracias amigo's

Sinister · 10-22-2009, 10:30 PM

You don't need vacuum to the booster when you bleed em, try bleeding them again.
I use a one man brake bleeder I got at Kragen for about $7. It's a little plastic bottle with a magnet and a tube coming out the top. Stick the bottle to the truck above the bleeder and pump the brakes til you have fluid in the bottle. Works great.

mclairmo · 10-23-2009, 01:10 AM

Make sure that the rod coming from the booster to the master is just barely bottoming out in the master cylinder piston. Sometimes there is a gap and that will cause your pedal to go to the floor because that rod has to travel a little bit before it actually touches the master cylinder piston and begins to push on it. I had to fab a spacer out of aluminum dowel to take up the slack and give me a normal pedal height.

PanelDeland · 10-23-2009, 06:11 AM

I agree with mclairmo.The rod for the power brakes is longer.If you didn't change yours,you may not have enough adjustment to get the length you need.There's no sense in bleeding them if your rod is too short.

Longhorn Man · 10-23-2009, 06:17 AM

you do want about 1/4 inch 'freeplay' on power brakes on the pedal.
However, I doubt the pushrod's length chainged while he was doing a brake job.
Try adjusting the shoes up, sounds a lot like the problem here.

cdowns · 10-23-2009, 07:23 AM

if you're getting dirty fluid out i'd continue to bleed regardless of pedal till you get nice clean stuff coming out

10-22-2009, 10:14 PM	#1
vectorit What? Join Date: Jun 2007 Location: Southern California Posts: 7,617	Brake bleeding Hey all, I am getting my high tech four drum power drum brakes back in order, and I just got through bleeding out what I thought was all the air pockets. With the truck not running I pumped and bled out each wheel, in the process the manual says too. Things were coming along great, got good pedal and thought this was too easy. Until I fired up the engine, and then pressed down on the brake pedal. Just as I expected, the pedal went straight to the floor. It did not come back up, and only has about an inch worth of travel. It's dark out now, and my lighting isn't all that great. So I will pick this up tomorow. Just wondering should I do this while there is vacuum to the booster? Or do I just start the process all over again then repeat, then run the engine to see if the pedal normalizes in it's travel and resistance? Fogive the basic question, it's just been years since I did this. Plus I am all by myself, in the past I had a buddy pump the brakes while I cracked the wheel cylinder bleed valve. Right now I am using a jar and rubber hose to catch all the dirty fluids. Gracias amigo's __________________ Chris 1968 K20 Suburban 1972 K10 LWB PU

10-22-2009, 10:30 PM	#2
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	Re: Brake bleeding You don't need vacuum to the booster when you bleed em, try bleeding them again. I use a one man brake bleeder I got at Kragen for about $7. It's a little plastic bottle with a magnet and a tube coming out the top. Stick the bottle to the truck above the bleeder and pump the brakes til you have fluid in the bottle. Works great. __________________ Beat it to fit, Paint it to match...

10-23-2009, 01:10 AM	#3
mclairmo Registered User Join Date: Jan 2006 Location: Take Off Posts: 1,908	Re: Brake bleeding Make sure that the rod coming from the booster to the master is just barely bottoming out in the master cylinder piston. Sometimes there is a gap and that will cause your pedal to go to the floor because that rod has to travel a little bit before it actually touches the master cylinder piston and begins to push on it. I had to fab a spacer out of aluminum dowel to take up the slack and give me a normal pedal height.

10-23-2009, 06:11 AM	#4
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,993	Re: Brake bleeding I agree with mclairmo.The rod for the power brakes is longer.If you didn't change yours,you may not have enough adjustment to get the length you need.There's no sense in bleeding them if your rod is too short. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

10-23-2009, 06:17 AM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Brake bleeding you do want about 1/4 inch 'freeplay' on power brakes on the pedal. However, I doubt the pushrod's length chainged while he was doing a brake job. Try adjusting the shoes up, sounds a lot like the problem here.

10-23-2009, 07:23 AM	#6
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Brake bleeding if you're getting dirty fluid out i'd continue to bleed regardless of pedal till you get nice clean stuff coming out __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY



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