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

skokie · 10-18-2004, 11:52 PM

I added a booster to my 68 1/2 ton. Its got drums in the front and back. I noticed tonight that when I push the brake pedal down the brakes dont start to work until about 2/3rds the way down. Is this normal or do I need to adjust the rod or brakes themselves?

Thanks

skokie · 10-19-2004, 12:05 AM

Forgot to put this in. I have checked the fluid and it is fine.

skokie · 10-19-2004, 12:19 AM

I pulled the master off of the booster and noticed the black rupper piece was kinda crumpled up. It fell off when I pulled the master out. How is this piece supposed to go back on?

Thanks

Tx Firefighter · 10-19-2004, 06:56 AM

You don't need the rubber piece anymore. It's used for when you are bolting the master cylinder directly to the firewall without a booster.

bobs409 · 10-19-2004, 07:45 AM

Quote:

Originally Posted by skokie

I added a booster to my 68 1/2 ton. Its got drums in the front and back. I noticed tonight that when I push the brake pedal down the brakes dont start to work until about 2/3rds the way down. Is this normal or do I need to adjust the rod or brakes themselves?

Thanks

It sounds like your brake shoes could use an adjustment. You can get a better pedal than that by cranking the shoes out closer to the drums.

I like drum brakes but an occasional adjustment is something that needs to be done with these. I'd get a can of brake cleaner and clean 'em up while your in there too.

skokie · 10-19-2004, 11:25 AM

Tx Firefighter I will remove that tonight.
Bobs 409 I know that its a star bolt that you have to adjust do you turn it to the left or right to tighten the brakes. Never done this before.

Thanks

bobs409 · 10-19-2004, 02:34 PM

That's it but it turns upward or downward. To move the shoes closer to the drum, turn the wheel downward. (when looking at it from the front)

There should be a slot in the brake drum so you can put a screwdriver in and turn it. Spin drum to check. I usually stop when there is some contact. You don't want too much contact though, just light.

skokie · 10-19-2004, 02:39 PM

Bobs409,
Thanks for the info. Truck is going to the tranny shop tonight for the 400 turbo rebuild so I will do this wen I get the truck back.
Thanks

mdazb · 10-19-2004, 03:28 PM

Can you use the same master cylinder when adding a booster? I heard the a different MC was needed.....

**53burb** · 10-19-2004, 03:54 PM

I am planning on doing this to a '69 Burb. Is it really beneficial w/o converting to front drums first?? Any suggestions before I do this??

Longhorn Man · 10-19-2004, 04:20 PM

Quote:

Originally Posted by mdazb

Can you use the same master cylinder when adding a booster? I heard the a different MC was needed.....

On most vehicles, you do indeed need a new master cylinder. however, the P/N for manual and power master cylinders are the same for these trucks.

I'm willing to bet that when you adjust your deums, you'll still have freeplay in the pedal. If so, you'll need to adjust the pushrod.
Did you hook the rod on the pedal to the other hole?

skokie · 10-19-2004, 04:55 PM

Longhorn Man
What other hole are you referring to?

Longhorn Man · 10-19-2004, 05:14 PM

From what I have read on here (never done a power conversion myself) there are two holes on the arm for the brake pedal. Moving from one to the other chainges the amount of leverage you are using to apply the piston movement in the master cylinder.
I'm 99% positive you are supposed to move the rod from one hole to the other when adding a booster.
Anyone else...am I remembering this correctly?

rodnok1 · 10-19-2004, 05:20 PM

Yea I think you are correct Longhorn Man, sounds just like the problems I had when converting to disc brakes, I had to move the linkage at the brake pedal.

skokie · 10-19-2004, 05:57 PM

Nope didnt do that. Ok where is this hole located on the brake pedal? Anyone got a pic?

Thanks

skokie · 10-20-2004, 12:02 AM

Well I started digging through the factory assembly manual and it looks like there is two holes. Heres the page from the assembly manual.

10-18-2004, 11:52 PM	#1
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,344	Brake question I added a booster to my 68 1/2 ton. Its got drums in the front and back. I noticed tonight that when I push the brake pedal down the brakes dont start to work until about 2/3rds the way down. Is this normal or do I need to adjust the rod or brakes themselves? Thanks __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

10-19-2004, 12:05 AM	#2
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,344	Forgot to put this in. I have checked the fluid and it is fine. __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

10-19-2004, 12:19 AM	#3
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,344	I pulled the master off of the booster and noticed the black rupper piece was kinda crumpled up. It fell off when I pulled the master out. How is this piece supposed to go back on? Thanks Attached Images __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

10-19-2004, 06:56 AM	#4
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	You don't need the rubber piece anymore. It's used for when you are bolting the master cylinder directly to the firewall without a booster. __________________ I'm on the Instagram- @Gearhead_Kevin

10-19-2004, 11:25 AM	#6
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,344	Tx Firefighter I will remove that tonight. Bobs 409 I know that its a star bolt that you have to adjust do you turn it to the left or right to tighten the brakes. Never done this before. Thanks __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

10-19-2004, 02:34 PM	#7
bobs409 1969 Custom 30 wrecker Join Date: Sep 2001 Location: Pottsville, Pa Posts: 2,611	That's it but it turns upward or downward. To move the shoes closer to the drum, turn the wheel downward. (when looking at it from the front) There should be a slot in the brake drum so you can put a screwdriver in and turn it. Spin drum to check. I usually stop when there is some contact. You don't want too much contact though, just light. __________________ Bob 63 Impala 283/PG/3.36 (under restoration) 66 Impala 327/PG/3.36 66 Chevelle SS 409/M22/3.55 69 Chevelle 307/PG/3.08 (future restoration) 69 C10 short stepside 454/TH350/3.73 69 Custom 30 tow truck 350/4 spd/4.10 (resto done, CRUISIN TIME!) 71 Cheyenne 20 fleetside 350/4 spd/4.10 71 Chevelle 6/PG/3.08 72 Chevelle 454/M21/4.10

10-19-2004, 02:39 PM	#8
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,344	Bobs409, Thanks for the info. Truck is going to the tranny shop tonight for the 400 turbo rebuild so I will do this wen I get the truck back. Thanks __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

10-19-2004, 03:28 PM	#9
mdazb Registered User Join Date: Oct 2004 Location: Nor Cal Posts: 75	Can you use the same master cylinder when adding a booster? I heard the a different MC was needed..... __________________ --------------------------------- 72 C10 SWB 350 Work in progress 98 HD Fatboy 09 HD Heritage Softail 05 Honda Element

10-19-2004, 03:54 PM	#10
53burb Senior Member Join Date: May 2004 Location: Queen Creek, AZ Posts: 1,007	I am planning on doing this to a '69 Burb. Is it really beneficial w/o converting to front drums first?? Any suggestions before I do this??

10-19-2004, 04:55 PM	#12
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,344	Longhorn Man What other hole are you referring to? __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

10-19-2004, 05:14 PM	#13
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	From what I have read on here (never done a power conversion myself) there are two holes on the arm for the brake pedal. Moving from one to the other chainges the amount of leverage you are using to apply the piston movement in the master cylinder. I'm 99% positive you are supposed to move the rod from one hole to the other when adding a booster. Anyone else...am I remembering this correctly?

10-19-2004, 05:20 PM	#14
rodnok1 Registered User Join Date: Jun 2003 Location: Linden, North Carolina Posts: 617	Yea I think you are correct Longhorn Man, sounds just like the problems I had when converting to disc brakes, I had to move the linkage at the brake pedal. __________________ 64 Panel Rebuild Pics Clutch Replacement and Borg Warner T10 Trans Rebuild 64 Panel 1/2 Ton 350cubes/400hp BorgWarner t-10 3:73 Auburn Posi

10-19-2004, 05:57 PM	#15
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,344	Nope didnt do that. Ok where is this hole located on the brake pedal? Anyone got a pic? Thanks __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

10-20-2004, 12:02 AM	#16
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,344	Well I started digging through the factory assembly manual and it looks like there is two holes. Heres the page from the assembly manual. Attached Images __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234



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