brake questions for 70 gmc 3/4 ton - The 1947 - Present Chevrolet & GMC Truck Message Board Network

wanted · 06-26-2003, 12:16 AM

I just installed a different front end in my 70 gmc 3/4ton 4x4. I wanted disks. I purchased a new master cylinder for a 72 chevy k20. I still need a proportioning valve. I will look for a used one but what years can I use? only 71 or 72? only 3/4 ton?
Also, I would like to add power to these brakes, so I will need a booster, bracket, and different pedal assembly I assume. What I need to know, is there differences between k10 and k20 as far as pedals and booster. Also are power drum brakes set up the same. I can buy a new booster for a 72 but I'm concerned about pedal assembly and bracket.
Any help would be appreciated, I don't have alot of donor trucks to choose from up here in Minnesota.

Thanks

darksaga · 06-26-2003, 12:57 AM

the prop. valve on mine is off of a '73 I belive any one should work untill gm went to metric fittings or low drag brakes. I would try to match wheelbase.

As for the booster and the braket, the booster can be had rebuilt but the bracket was a pain for me to get, there are 2 booster brackets that I know of long and short and there is two mc pushrods short and long from what I found in fixing the bungled job I had when I got my truck (drum master discb brakes) it had the short bracket/long pushrod (benidix) and I needed long bracket/short pushrod. I ended up bidding on ebay for the bracket plus the booster

**JIMs70GMC** · 06-26-2003, 07:12 PM

wanted-Check your private messages.

Welcome to the board!

da-burb · 06-26-2003, 11:26 PM

pm'ed U

da-burb · 06-26-2003, 11:26 PM

pm'ed U

sakohntr · 06-29-2003, 02:37 AM

1- pm'd ya
2- welcome to the board
3- i am 30 minutes from ya
4- have all the parts ya need.

06-26-2003, 12:16 AM	#1
wanted Registered User Join Date: May 2003 Location: duluth, mn Posts: 63	brake questions for 70 gmc 3/4 ton I just installed a different front end in my 70 gmc 3/4ton 4x4. I wanted disks. I purchased a new master cylinder for a 72 chevy k20. I still need a proportioning valve. I will look for a used one but what years can I use? only 71 or 72? only 3/4 ton? Also, I would like to add power to these brakes, so I will need a booster, bracket, and different pedal assembly I assume. What I need to know, is there differences between k10 and k20 as far as pedals and booster. Also are power drum brakes set up the same. I can buy a new booster for a 72 but I'm concerned about pedal assembly and bracket. Any help would be appreciated, I don't have alot of donor trucks to choose from up here in Minnesota. Thanks

06-26-2003, 12:57 AM	#2
darksaga Registered User Join Date: Nov 2002 Location: santa cruz cali Posts: 118	the prop. valve on mine is off of a '73 I belive any one should work untill gm went to metric fittings or low drag brakes. I would try to match wheelbase. As for the booster and the braket, the booster can be had rebuilt but the bracket was a pain for me to get, there are 2 booster brackets that I know of long and short and there is two mc pushrods short and long from what I found in fixing the bungled job I had when I got my truck (drum master discb brakes) it had the short bracket/long pushrod (benidix) and I needed long bracket/short pushrod. I ended up bidding on ebay for the bracket plus the booster __________________ 1968 gmc 3/4 4x4 longbed. built 469 700r4 (needs a th400 REAL SOON!), 14bolt ff rear 73 3/4 dana 44 1970 chevelle all wheel disc, tubular rear control arms tall spindle swap up front matching #'s 350 work in Progress Last edited by darksaga; 06-26-2003 at 01:03 AM.

06-26-2003, 07:12 PM	#3
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	wanted-Check your private messages. Welcome to the board! __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

06-26-2003, 11:26 PM	#4
da-burb "Ochre Ogre" Join Date: Apr 2000 Location: Springfield, MN Posts: 3,558	pm'ed U __________________ Bowtie Truck Stop Inc. Mid-West GM Truck Restoration Parts Supplier Your Key Parts, Auto Metal Direct, Dynacorn, and Goodmark dealer. like us @ www.facebook.com/BowtieTruckStop 1971 C-10 Suburban (Ochre) 1971 K-10 Suburban (Ochre) 1972 C-10 Suburban (Ochre) 1972 K-20 Suburban (Yellow- that just aint right!) Springfield, Minnesota 56087

06-26-2003, 11:26 PM	#5
da-burb "Ochre Ogre" Join Date: Apr 2000 Location: Springfield, MN Posts: 3,558	pm'ed U __________________ Bowtie Truck Stop Inc. Mid-West GM Truck Restoration Parts Supplier Your Key Parts, Auto Metal Direct, Dynacorn, and Goodmark dealer. like us @ www.facebook.com/BowtieTruckStop 1971 C-10 Suburban (Ochre) 1971 K-10 Suburban (Ochre) 1972 C-10 Suburban (Ochre) 1972 K-20 Suburban (Yellow- that just aint right!) Springfield, Minnesota 56087

06-29-2003, 02:37 AM	#6
sakohntr Registered User Join Date: Mar 2002 Location: Floodwood Minnesota Posts: 1,057	brake parts 1- pm'd ya 2- welcome to the board 3- i am 30 minutes from ya 4- have all the parts ya need. __________________ 1967 K30 Napco 292/SM420 original paint 30k miles 1968 K60 Napco 396/5spd. dbl frame 52" michelins 1969 K10 SWB GMC 454/4spd 6" 35's posi,hooks 1972 C30 longhorn,BB/AT,A/C,Tilt,Toolbox,lokr 1987 K20 Chevrolet Suburban. 6" lift. 5.7L/TH400 1979 K60 GMC Coleman 4x4, 427/Allison.



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