Help w/Power Brakes - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Sonny · 02-22-2005, 01:47 PM

I am trying to retrofit a 72 power brake system (booster, master cylinder, prop. valve) to my 68 C-10. With the system installed, the brake master cylinder looks like it is leaning down too much. Will the 72 unit work on a 68?

Thanks in Advance!

Sonny

**CPNE** · 02-22-2005, 01:50 PM

It should but if you still have drums front and rear you want to use the master cylinder and prop valve from the 68. As far as leaning, do you have pic?

Sonny · 02-22-2005, 01:56 PM

I don't have a pic yet. I have front disc/drum rear(5-lug). The 72 I pulled the unit from had disc/drum setup I believe. I didn't look too hard. Plus the support brackets do not line up anywhere on mine. I do have a pretty agressive stance too. I will try and attach a picture in a few. I remember someone looking for the boot that goes on the firewall. I found a part number and I ordered one from the chevy place. I am supposed to get it tomorrow.

**CPNE** · 02-22-2005, 02:00 PM

If the unit you pulled is truely for a 72, the support bracket should line up with the 4 studs off the pedals coming thru the firewall. Direct bolt-on, zero issues.

whitesswj · 02-22-2005, 02:05 PM

Quote:

Originally Posted by CPNE

It should but if you still have drums front and rear you want to use the master cylinder and prop valve from the 68.

sorry to stepin. But i have a 68 w/ drum/drum. and i don't want to go to disc yet or anytime soon too and i'm wanting to go to a power break setup so my wife can stop the truck. You're telling me that if i get the rod and brackets then all i've got to do is unbolt the master move it forward put the pwr set up in and bolt the rod up and the master cyl to the booster and i'm done. so all i need to be looking for is a power setup minus the master cyl and prop valve? is this what you're saying CPNE?? if so then you just helped me out a lot on my search to have my wife driving my truck once it's done.

i don't know about you guys but seeing a grown woman drivin a pickup of any size is very attractive to me.

thanks sswj

Putter · 02-22-2005, 02:08 PM

Yep. I added power to my drum/drum system. Moved the master forward, slid the booster in place and bolted her up. Ran the vacuum hose to the intake and BOOM...POWER BRAKES. Running fine for many months now.

krue · 02-22-2005, 02:10 PM

white, that's all I did. You don't even have to unhook the brake lines from the m/c. You will need to lengthen the brake sensor wire though (I just left mine disconnected.)

Sonny · 02-22-2005, 03:58 PM

Here are some pics. You can see how much the booster/cylinder tilts down.

Try: http://www.heartofgeorgiaspeedway.com/truck.html
Sonny

Sonny · 02-22-2005, 04:05 PM

The brackets I were talking about are the two extra brackets that angle down to the firewall. In my excitement to paint and install the brackets I didn't pay much attention to their exact orientation. The booster bracket bolted up nicely.

LUV2XCLR8 · 02-22-2005, 04:57 PM

Looks Like Mine

**CPNE** · 02-22-2005, 05:27 PM

Quote:

Originally Posted by Sonny

The brackets I were talking about are the two extra brackets that angle down to the firewall. In my excitement to paint and install the brackets I didn't pay much attention to their exact orientation. The booster bracket bolted up nicely.

They won't line up to anything on your cab. They were added in 71, so an older cab won't have the provision for a bolt on the firewall.

Sonny · 02-22-2005, 06:13 PM

Now my question is which line goes where? Originally the front line went to the front brakes and the rear line went to the back. Do I still do this even though the bigger line going to the prop valve goes to the rear? I was planning to hook them up the same orientation: Front brake line to the bottom hole in the front of the valve and the rear brake line connecting to the back hole. FYI save the b-nuts from the donor truck's brake lines. Mine didnt match up and I have to go back tomorrow and get them.

whitesswj · 02-22-2005, 07:29 PM

the tilt has nothing to do with pressure, i wouldn't worry abou it .

and to the resopnse on the drmdrm master.......SWEET!!!!
I can lower my standards and find a good one to get . thanks guys!

sswj

**CPNE** · 02-22-2005, 09:05 PM

Quote:

Originally Posted by Sonny

Now my question is which line goes where? Originally the front line went to the front brakes and the rear line went to the back. Do I still do this even though the bigger line going to the prop valve goes to the rear? I was planning to hook them up the same orientation: Front brake line to the bottom hole in the front of the valve and the rear brake line connecting to the back hole. FYI save the b-nuts from the donor truck's brake lines. Mine didnt match up and I have to go back tomorrow and get them.

Whichever fluid resevoir is larger is the one to use for the front disks. 3/4 ton boosters/master cylinders have the larger resevior in the rear. 1/2 tons have it in the front. Either one is fine for the conversion, just route the larger to the front disks.

Sonny · 02-22-2005, 09:23 PM

Both of the reservoirs are the same size. The back reservoir has the larger line coming from it. I will try and hook up the front brake line to the larger aft port on the prop. valve and see what happens...

Thanks for all of the help!

Sonny

02-22-2005, 01:47 PM	#1
Sonny Active Member Join Date: Jan 2004 Location: Centerville, GA Posts: 240	Help w/Power Brakes I am trying to retrofit a 72 power brake system (booster, master cylinder, prop. valve) to my 68 C-10. With the system installed, the brake master cylinder looks like it is leaning down too much. Will the 72 unit work on a 68? Thanks in Advance! Sonny

02-22-2005, 01:50 PM	#2
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,664	It should but if you still have drums front and rear you want to use the master cylinder and prop valve from the 68. As far as leaning, do you have pic? __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all

02-22-2005, 02:00 PM	#4
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,664	If the unit you pulled is truely for a 72, the support bracket should line up with the 4 studs off the pedals coming thru the firewall. Direct bolt-on, zero issues. __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all

02-22-2005, 02:08 PM	#6
Putter More Cowbell.... Join Date: Mar 2004 Location: Puckett, MS Posts: 3,569	Yep. I added power to my drum/drum system. Moved the master forward, slid the booster in place and bolted her up. Ran the vacuum hose to the intake and BOOM...POWER BRAKES. Running fine for many months now. __________________ *There once was a member from Puckett.....Who ( fill in the blank blank blank* ) bucket**

02-22-2005, 02:10 PM	#7
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	white, that's all I did. You don't even have to unhook the brake lines from the m/c. You will need to lengthen the brake sensor wire though (I just left mine disconnected.) __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

02-22-2005, 01:56 PM	#3
Sonny Active Member Join Date: Jan 2004 Location: Centerville, GA Posts: 240	I don't have a pic yet. I have front disc/drum rear(5-lug). The 72 I pulled the unit from had disc/drum setup I believe. I didn't look too hard. Plus the support brackets do not line up anywhere on mine. I do have a pretty agressive stance too. I will try and attach a picture in a few. I remember someone looking for the boot that goes on the firewall. I found a part number and I ordered one from the chevy place. I am supposed to get it tomorrow.

02-22-2005, 03:58 PM	#8
Sonny Active Member Join Date: Jan 2004 Location: Centerville, GA Posts: 240	Here are some pics. You can see how much the booster/cylinder tilts down. Try: http://www.heartofgeorgiaspeedway.com/truck.html Sonny Last edited by Sonny; 02-22-2005 at 04:09 PM.

02-22-2005, 04:05 PM	#9
Sonny Active Member Join Date: Jan 2004 Location: Centerville, GA Posts: 240	The brackets I were talking about are the two extra brackets that angle down to the firewall. In my excitement to paint and install the brackets I didn't pay much attention to their exact orientation. The booster bracket bolted up nicely.

02-22-2005, 04:57 PM	#10
LUV2XCLR8 The LuvShack Garage Join Date: Jan 2004 Location: Maple Grove, TN (West Side) Posts: 30,475	Looks Like Mine __________________ Owner/Op: "TN Classic Transport Carriers" The Toy: "Square Vette" 72 Hybrid Blazer Toy Barn: "LuvShack" 40 x 60 x 20 Shop Big Piggy: "Goliath" 07 Kodiak C4500 Lil Piggy:"Maddy" 88 Silverado 3500 Hauler: "Feathers" 14 Aluma 8218T

02-22-2005, 06:13 PM	#12
Sonny Active Member Join Date: Jan 2004 Location: Centerville, GA Posts: 240	Now my question is which line goes where? Originally the front line went to the front brakes and the rear line went to the back. Do I still do this even though the bigger line going to the prop valve goes to the rear? I was planning to hook them up the same orientation: Front brake line to the bottom hole in the front of the valve and the rear brake line connecting to the back hole. FYI save the b-nuts from the donor truck's brake lines. Mine didnt match up and I have to go back tomorrow and get them.

02-22-2005, 07:29 PM	#13
whitesswj Embrace the Redneck Join Date: Jan 2004 Location: Cabot, AR Posts: 1,334	the tilt has nothing to do with pressure, i wouldn't worry abou it . and to the resopnse on the drmdrm master.......SWEET!!!! I can lower my standards and find a good one to get . thanks guys! sswj __________________ '01 Camaro *Son, you just can't get there from here...*

02-22-2005, 09:23 PM	#15
Sonny Active Member Join Date: Jan 2004 Location: Centerville, GA Posts: 240	Both of the reservoirs are the same size. The back reservoir has the larger line coming from it. I will try and hook up the front brake line to the larger aft port on the prop. valve and see what happens... Thanks for all of the help! Sonny



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