NBS Front Brake Swap for OBS Trucks

Discussion in 'Axles + Brakes' started by Mike, Apr 4, 2013.

  1. Mike

    Mike Administrator Deluxe

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    Credit goes to Rocky Thornton:

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    If you do this brake swap on your OBS truck you will be amazed at the difference. Your best bet would be to go to the auto salvage yard and buy a pair of steering knuckles complete with hubs, brake rotors, calipers, ABS sensors, etc. I got mine off a 2000 Z-71 which had 12-inch rotors for use with 16-inch wheels. Since I have 17-inch wheels, I bought 13-inch rotors and calipers for a 2006 Z-71 and bolted them on the 2000 knuckles. If you do that, be sure that you get the calipers WITH the mounting brackets and they will fit perfect, Stay with the 2000-style hubs, because the 2006 hubs are different and the ABS leads will not plug into your OBS connectors. The 2000-style brake hoses are much longer than the OBS hoses and will need to be routed differently. The NBS hoses will clip directly onto your frame-mounted brackets, but you will need a brass fitting to adapt your 3/16 steel lines to the hoses that are designed for 1/4 steel lines. The NBS brake hoses have 2 metal brackets crimped onto them for mounting the hoses along the way to the frame. I pried-off the bigger bracket and discarded it. I pried-off the smaller bracket and modified it for reuse. You will see what I am talking about when you see the pictures.

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    I ordered a tapered reamer off Ebay for a 2-inch per foot taper and reamed the NBS knuckles with a ratchet & socket until the larger OBS ball joint studs fit perfectly. The tierod stud hole was the same on both, just had to turn the tierod 180-degrees. The hubs were different but the OBS axles fit the NBS hubs perfectly. The ABS wires plugged right in,too. Even the NBS brake hoses fit the OBS brake lines perfect. I went to the NAPA parts store for fresh calipers and rotors and made another huge discovery. The '06-up trucks went to a 13-inch rotor and bigger dual piston calipers that fit right on the '05-back NBS knuckles. The 13-inch setup requires at least 17-inch wheels, as mine barely clear the calipers. The 2010
    trucks went to 14-inch rotors that would require 18-inch wheels, but the new 13-inch setup I have now is all the brakes I need. They have already saved my ass a couple of times while towing a trailer behind idiot drivers. I am so happy to have factory engineered readily available big brakes on the front of my Yukon 4x4.

    You can buy the reamer off Ebay for $110 total, item no. 200633129977, and do it yourself with a ratchet & socket. Have an OBS upper and lower ball joint handy to check your progress as you ream. When I was reaming the hole for the lower ball joint, I had an old axle shaft handy, too. When I had reamed the lower hole enough for the lower ball joint stud to go thru, I put the lower ball joint in the knuckle and put the axle into the hub to check for clearance between the top of the lower ball joint and the CV joint of the axle shaft. I think I had to ream the hole a little more for clearance, and I may have had to use a flat washer under the ball joint nut so the cotter pin hole would align with the castle nut properly. If your truck is not 4x4, that won't be a problem.

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    If your truck is 4x4, a minor modification must be done to the CV joint of the axle shaft. There is a small deflector shield on the CV joint that will contact the back side of the knuckle when the axle shaft is pushed all the way into the hub. That little deflector shield can be tapped-down all the way around so it does not rub on the back of the knuckle. The picture will show what I am describing. With those modifications done to the NBS knuckles and the OBS axle CV joints, you simply remove your OBS steering knuckles & brakes and install the NBS knuckles & brakes. You will have to turn your outer tierod ends 180-degrees to connect to the NBS knuckles. You will have to route the NBS brake hose right by the nut of the upper ball joint and up thru the middle of the upper control arm to the mounting bracket on the frame. You will have to make a small bracket out of flat metal to hold the brake hose where it comes up behind the upper ball joint. Use one of the 4 bolts of the upper ball joint to hold the bracket and form a loop on the other end of the flat metal to wrap around the brake hose. When you have adjusted the position of the hose in the loop, crimp it onto the hose just enough to hold the hose in place. You should make another small bracket out of flat metal to go under the nut of the upper ball joint to hold the brake hose at that location, too. Look at the pictures and you will see how the hose is routed.

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    The brake hoses are different for right and left sides and they index to the frame brackets differently, so check to make sure that the hose fits the frame bracket notches for the side you are working on before you get too far along with the hose installations. I mentioned earlier that I pried-off and modified the smaller bracket from the NBS brake hose for reuse...I flattened the bracket and drilled a big hole in it to go under the nut of the upper ball joint to hold the brake hose there. You will see it in the picture. All that is left is to route the ABS wire along the upper control arm to the frame and plug it in, bleed the brakes, install the tires and make sure the brake hoses do not rub on the back side of the tires or wheels when turning both ways, and you're done. Your truck will be updated with bigger, better, factory designed brakes and can be serviced with readily-available parts anytime, anywhere. You will wonder why the factory did not build it that way in the first place. Your truck will now decelerate as good as it accelerates.

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    Thanks again Rocky! -Mike
     
    Erick2door and TheRabbitChaser like this.
  2. TylerZ281500

    TylerZ281500 Yukon Ridin High

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    thats awesome!
     
  3. JollyGreen

    JollyGreen Metalworking Madman

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    So will this work for the 3/4 ton trucks as well? I would assume so.

    Sent from my GANG GREEN DROiD
     
  4. great white

    great white Retirement countdown!

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    Off the top of my head I'm going to say no as the cv shafts are bigger on 2500/3500's.

    Im thinking you might get away with swapping out the unit bearing to the 2500 one to make it work.

    The ball joints are the same so that part should work.

    Thats from memory, so i might be off the beam a bit....
     
  5. FastOrange

    FastOrange OBSless

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    to bad this wont work on 2wd :(
     
  6. 2000CCSB

    2000CCSB CrewCab Stalker

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    It could work on 2wd right lug swap:D may still not work IDK for sure. where theres a wheel theres a way.

    CrewCab Steve
     
  7. 88GMCtruck

    88GMCtruck I'm all 8-Luggy!

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    Nice info! If I get another IFS K1500 this will be on the to-do list.
     
  8. Mike

    Mike Administrator Deluxe

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    If you have a 2wd just use NBS 2wd spindles, might be different size BJs though.

    If you have a 2500/3500 just use NBS 2500/3500 spindles and tell us if the CVs fit. =)
     
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  9. great white

    great white Retirement countdown!

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    That I do believe would work.

    I seem to recall on another board some guys swapping the 2500/3500 shafts and knuckles to get the larger shafts into a 1500.

    someone would have to go "Google commando" to find it though.....
     
  10. oohunter04oo

    oohunter04oo Like a Rock

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    This is awesome Info! could be another way to convert a 2wd 5 lug to 6 lug. but the main think you would have to worry about is how far in or out it puts the front wheels.

    Did it change the track width any on the 4wd?
     

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