Converting a 70 Jimmy to disc brakes... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

k5xjfiles · 11-13-2009, 05:08 PM

Can anyone tell me if the flat top knuckles, spindles, hubs, rotors etc from a mid 70s 1/2 blazer will mount right on to a 1970 GMC Jimmy 4x4 that now has drum brakes. A guy I met has drums up front, and Ive got all these disc parts that he will buy if he can bolt em up and go.
thanks in advance....

69TowRig · 11-14-2009, 07:11 PM

See this older thread on the topic. It has been hashed over many times, my opinion (after doing that exact swap) is to just get an entire front axle and swap it in. Much less time and money.

http://www.67-72chevytrucks.com/vboa...highlight=disc

**pound41** · 11-14-2009, 08:26 PM

My 70 had blazer had power drum brakes someone swapped in a newer complete disc front end They left the power drum master/prop valve etc and the brakes were soft. I had to switch those. But the old lines have different size fittings so you have to do some adapting or swith the front lines I don't think the front lines unions are in the same place

swyfor5 · 11-14-2009, 09:54 PM

When I first bought my K5 I swapped out the front axle from a 72 donor K5. Gave me the disc brakes up front. Was a easy swap, now getting ready to swap again. Going 1 Ton axles this time, First swap was in 1981, 1 Ton swap will probably be in 2011. Only 30 years later, hope I live that long!

11-13-2009, 05:08 PM	#1
k5xjfiles Junior Member Join Date: Apr 2005 Location: Stokesdale, NC Posts: 100	Converting a 70 Jimmy to disc brakes... Can anyone tell me if the flat top knuckles, spindles, hubs, rotors etc from a mid 70s 1/2 blazer will mount right on to a 1970 GMC Jimmy 4x4 that now has drum brakes. A guy I met has drums up front, and Ive got all these disc parts that he will buy if he can bolt em up and go. thanks in advance.... __________________ 72 K5/10/20 Hybrid 350, 465/205 44/14 bolt 35s, Detroit locker 89 XJ Pioneer, 4.5" 32s. 98 ZJ DD. Parting..87-01 Cherokees I bore throttle bodies-PM me for details!

11-14-2009, 07:11 PM	#2
69TowRig Senior Member Join Date: Jan 2005 Location: Raleigh, NC Posts: 894	Re: Converting a 70 Jimmy to disc brakes... See this older thread on the topic. It has been hashed over many times, my opinion (after doing that exact swap) is to just get an entire front axle and swap it in. Much less time and money. http://www.67-72chevytrucks.com/vboa...highlight=disc __________________ -Chris Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid. Also building a 1950 Willys CJ-3A and off-roading a 2001 Nissan Frontier on 1-Ton Portals...

11-14-2009, 08:26 PM	#3
pound41 Registered User Join Date: Dec 2002 Location: Northern Virginia Posts: 1,269	Re: Converting a 70 Jimmy to disc brakes... My 70 had blazer had power drum brakes someone swapped in a newer complete disc front end They left the power drum master/prop valve etc and the brakes were soft. I had to switch those. But the old lines have different size fittings so you have to do some adapting or swith the front lines I don't think the front lines unions are in the same place

11-14-2009, 09:54 PM	#4
swyfor5 Registered User Join Date: May 2007 Location: Marion, Mi. Posts: 2,429	Re: Converting a 70 Jimmy to disc brakes... When I first bought my K5 I swapped out the front axle from a 72 donor K5. Gave me the disc brakes up front. Was a easy swap, now getting ready to swap again. Going 1 Ton axles this time, First swap was in 1981, 1 Ton swap will probably be in 2011. Only 30 years later, hope I live that long!



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