What do you think it could be?? ( BRAKES ) - The 1947 - Present Chevrolet & GMC Truck Message Board Network

sam's 72 · 03-26-2003, 09:11 PM

I did a complete brake job on the 72, everything new, I got to drive it today and it seems to me that the front brakes are working harder then the back brakes. do you think it could be the proportionate valve, ( it is new ) or do you think I need to do some more adjusting on back brakes? Just how much should you adjust the shoe out on the back?
Sam

68 Suburban · 03-26-2003, 09:21 PM

Sam, when I did my Praise brakes it took a little bit to break in. Did you open the system at all? May be they need more bleeding. It also could be that you need to adjust the rears out more. You want them so there is a slight drag on the drum.

sam's 72 · 03-26-2003, 09:25 PM

Yes I had the whole system opened, I replaced everything, booster, master cylinder, porportion valve, everyone of the brake lines, calipers, wheel cylinders, and all rubber hoses. I bleed the system really good, I was going to give it a few days of driving and rebleed to see how it looks. I adjusted the back shoes out some, but they don't have any drag on them, you can turn them easy. So this might be it.
Sam

68 Suburban · 03-26-2003, 09:31 PM

Yes, you want a minor drag on them.

sam's 72 · 03-27-2003, 10:45 PM

OK, I adjusted the rear brakes. It still seems like the front brake is doing all the work. The propotionate valve I bought is a rebuild, I could not find a new one. I wonder if I should get one that is adjustable?
Sam

Blue68 · 03-28-2003, 01:35 PM

Sam,
The front brakes will do 70-80% of the work. Now if you go down a dirt road and lock up (as much as you can) your brakes and the backs don't slide out, then you need to re-adjust the rears. It may also be that you tripped your prop valve (most likely not or your brake light would be on). You really don't want your rear brakes doing a lot of work. Having the rear go to the front on a wet surface can be a bit disconcerting.

Capitol68 · 03-28-2003, 06:45 PM

did u adjust the backs by driving in reverse and slamming on the brakes ? do this about 4 or 5 times, should bring them up to equal. ie, this adjusts the drum brakes

sam's 72 · 03-28-2003, 07:20 PM

Thanks for the replies guys! They are doing good now, I pulled the tires back off and readjusted them, then once I got them adjusted, I backed up about 4 time and let them get adjust this way also. They are much much better now! Thanks for the help, thats why I like this board so much
Sam

Capitol68 · 03-28-2003, 09:39 PM

good glad to hear it ! Brakes are good to have

03-26-2003, 09:11 PM	#1
sam's 72 Senior Member Join Date: Nov 2001 Location: Pasadena, Texas, USA Posts: 1,005	What do you think it could be?? ( BRAKES ) I did a complete brake job on the 72, everything new, I got to drive it today and it seems to me that the front brakes are working harder then the back brakes. do you think it could be the proportionate valve, ( it is new ) or do you think I need to do some more adjusting on back brakes? Just how much should you adjust the shoe out on the back? Sam __________________ 72 LWB chevy truck. Pasadena, Texas

03-26-2003, 09:21 PM	#2
68 Suburban Registered User Join Date: Oct 2000 Location: From Chicago, Live in Phoenix, AZ Posts: 6,802	Sam, when I did my Praise brakes it took a little bit to break in. Did you open the system at all? May be they need more bleeding. It also could be that you need to adjust the rears out more. You want them so there is a slight drag on the drum. __________________ Just sitting here contemplating contemplation.

03-26-2003, 09:25 PM	#3
sam's 72 Senior Member Join Date: Nov 2001 Location: Pasadena, Texas, USA Posts: 1,005	Yes I had the whole system opened, I replaced everything, booster, master cylinder, porportion valve, everyone of the brake lines, calipers, wheel cylinders, and all rubber hoses. I bleed the system really good, I was going to give it a few days of driving and rebleed to see how it looks. I adjusted the back shoes out some, but they don't have any drag on them, you can turn them easy. So this might be it. Sam __________________ 72 LWB chevy truck. Pasadena, Texas

03-26-2003, 09:31 PM	#4
68 Suburban Registered User Join Date: Oct 2000 Location: From Chicago, Live in Phoenix, AZ Posts: 6,802	Yes, you want a minor drag on them. __________________ Just sitting here contemplating contemplation.

03-27-2003, 10:45 PM	#5
sam's 72 Senior Member Join Date: Nov 2001 Location: Pasadena, Texas, USA Posts: 1,005	OK, I adjusted the rear brakes. It still seems like the front brake is doing all the work. The propotionate valve I bought is a rebuild, I could not find a new one. I wonder if I should get one that is adjustable? Sam __________________ 72 LWB chevy truck. Pasadena, Texas

03-28-2003, 01:35 PM	#6
Blue68 Registered User Join Date: Apr 2000 Location: Frisco, Tx, USA Posts: 606	Sam, The front brakes will do 70-80% of the work. Now if you go down a dirt road and lock up (as much as you can) your brakes and the backs don't slide out, then you need to re-adjust the rears. It may also be that you tripped your prop valve (most likely not or your brake light would be on). You really don't want your rear brakes doing a lot of work. Having the rear go to the front on a wet surface can be a bit disconcerting. __________________ http://home.comcast.net/~r.landrum/w...tos.html-.html '68 C-10 LWB, '98 Z-71 350 w/accessories (Serpentine), Edelbrock Performer, Edelbrock 1405 (600cfm) carb, GM HEI, CompCam Extreme 4x4 roller cam, Thorley Headers, Carter Electric Fuel Pump, Vintage Air, 700r4, 3.73, disc brakes and power steering upgrades.

03-28-2003, 06:45 PM	#7
Capitol68 Registered User Join Date: Sep 2002 Location: Austin,Tx Posts: 327	did u adjust the backs by driving in reverse and slamming on the brakes ? do this about 4 or 5 times, should bring them up to equal. ie, this adjusts the drum brakes __________________ '68 Fleet LWB orig 307 .030 over GM Hei/w Accel Super coil orig. stock TH 400. _______________________ “What we do for ourselves dies with us. What we do for others and the world remains and is immortal.” Albert Pine English author d.1851

03-28-2003, 07:20 PM	#8
sam's 72 Senior Member Join Date: Nov 2001 Location: Pasadena, Texas, USA Posts: 1,005	Thanks for the replies guys! They are doing good now, I pulled the tires back off and readjusted them, then once I got them adjusted, I backed up about 4 time and let them get adjust this way also. They are much much better now! Thanks for the help, thats why I like this board so much Sam __________________ 72 LWB chevy truck. Pasadena, Texas

03-28-2003, 09:39 PM	#9
Capitol68 Registered User Join Date: Sep 2002 Location: Austin,Tx Posts: 327	good glad to hear it ! Brakes are good to have __________________ '68 Fleet LWB orig 307 .030 over GM Hei/w Accel Super coil orig. stock TH 400. _______________________ “What we do for ourselves dies with us. What we do for others and the world remains and is immortal.” Albert Pine English author d.1851



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