|
10-25-2002, 12:19 PM
|
#1 |
|
Lurking Member
Join Date: Feb 2000
Location: Forest Grove, OR USA
Posts: 196
|
Disc proportioning
When I mount my disc brakes on the back of my K2500, do I have to use a proportioning valve? The calipers rotors and pads are all the same as the ones on the front.
__________________
JJ 72 GMC 1500 350 4 Speed, stone stock baby!!!!! 72 GMC K-2500 350TPI 700R4 For those who fought for it, Freedom has a flavor the protected will never know. 
|
|
|
|
10-25-2002, 01:29 PM
|
#2 |
|
Senior Member
 
Join Date: Jul 2000
Location: North Texas
Posts: 3,663
|
I would install w/o the prop valve. If the rears lock-up prematurely, you can add one of those adjustable valves to get it just right.
__________________
Mike 1969 C10 LWB -- owned for 36 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- converted from 250-six to roller cam 350, Vortec heads -- sold 1981 C10 Silverado LWB, 305, TH350C -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then! |
|
|
|
|
10-25-2002, 02:11 PM
|
#3 |
|
Registered User
Join Date: Jun 2002
Location: Camas, Wa
Posts: 58
|
jj
I would definitly use a prop valve.
__________________
71 c-10 6cyl  68 Camaro (wifes) 65 dodge town wagon (wanna buy it?) 97 crew cab f350 psd |
|
|
|
|
10-25-2002, 02:58 PM
|
#4 |
|
Senior Member
Join Date: Jul 2000
Location: North Texas
Posts: 3,663
|
Stock prop valves were for front disc/rear drums and may not work properly for a disc/disc setup. For example, Brother's Trucks sells different valves for disc/drum and disc/disc. However, your best bet is an adjustable valve that lets you tune your braking system so the rears don't lock up before the fronts. Summit Racing sells a couple different models for $39.50 to $75.95.
__________________
Mike 1969 C10 LWB -- owned for 36 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- converted from 250-six to roller cam 350, Vortec heads -- sold 1981 C10 Silverado LWB, 305, TH350C -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then! |
|
|
|
|
10-25-2002, 04:41 PM
|
#5 |
|
Almost Satisfied
 
Join Date: Mar 2002
Location: Springfield, MO
Posts: 2,932
|
From what I have read and with talking to different folks at various vendors they all seem to universily agree that you should not put disc brakes on the rear of our trucks (that is why I choose not to) but if you do go ahead and do it I would definately get a prop valve that is adjustable for disc/disc. CCP sells one, but I don't know how well it works.
__________________
1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far." |
|
|
|
|
10-25-2002, 04:53 PM
|
#6 |
|
Lurking Member
Join Date: Feb 2000
Location: Forest Grove, OR USA
Posts: 196
|
What would be the reason for not using them on the rear axle? They seem to increase braking performance on the front axles. Seems like more and more vehicle manufacturers are using them all the way around now.
__________________
JJ 72 GMC 1500 350 4 Speed, stone stock baby!!!!! 72 GMC K-2500 350TPI 700R4 For those who fought for it, Freedom has a flavor the protected will never know.
|
|
|
|
|
10-25-2002, 05:37 PM
|
#7 |
|
Fabricate till you "puke"
Join Date: Jun 2002
Location: Ill
Posts: 9,402
|
The @ss end is really pretty light,& probably doesnt need disc brakes unless you are hauling a lot of heavy loads(they will lock & slide). If you do opt for disc brakes, i think the adjustable valve would be the way to go. Good luck....crazy AL
|
|
|
|
|
10-25-2002, 10:57 PM
|
#8 |
|
Registered User
Join Date: Oct 2002
Location: Virginia
Posts: 226
|
since we are on the subject of prop valves. would i have to get a new one to add power brakes to my disc/drum manual brake truck? or could i just bolt on a booster and go?
|
|
|
|
|
10-26-2002, 07:24 PM
|
#9 |
|
Senior Member
Join Date: Jul 2000
Location: North Texas
Posts: 3,663
|
I would expect the prop valve is the same for manual and power brakes. It's still working with the same pressure -- you just don't have to push as hard with power brakes to generate the pressure!
__________________
Mike 1969 C10 LWB -- owned for 36 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- converted from 250-six to roller cam 350, Vortec heads -- sold 1981 C10 Silverado LWB, 305, TH350C -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then! |
|
|
|
 |
| Bookmarks |
| Thread Tools | |
| Display Modes | |
|
|
Linear Mode
