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DIY 1947-1954 2ton front disc brake conversion

Discussion in 'The Antiquated' started by Pat Stephens, Aug 17, 2018.

  1. Pat Stephens
    Joined: Jan 26, 2017
    Posts: 8

    Pat Stephens

    So about a year and half ago give or take i started pestering you guys with all sorts of questions about a front axle swap to put disc brakes on my old 1952 Chevy truck know as the AD 6400 series. I just completed this and will have a full parts list to directly swap to discs to make your truck a bit safer/modern and aslo the simplicity of being able to buy off the shelf parts. I also dont take responsibility for anything you do to your vehicle, this worked for me. That being said lets check it out! Its my first DIY so i tried to cover all the bases


    Step 1- find a p30 chassis or a mid 90's chevy C3500HD with 10 lug wheels.
    *I USED THE C3500HD AXLE FOR PARTS TO ADD TO THE ORIGINAL- cost from junkyard $350*
    Step 2- cut the leaf spring u bolts and take the whole front axle from the p30/c3500hd, save everything you can minus the leafs

    Step 3- This is where it gets a little hecktic and time consuming it took me about a year and a half to locate people to do some machine work/heavy welding for me and save up money for this upgrade. So remove everything and be sure to take pictures of everything. You want to remove everything on the old axle and set it in a pile for later.
    *IF YOU USE A C3500HD AXLE* Make sure to save the drag links and steering arms from the spindles you will need to modify them later.
    *P30 AXLE USERS* i did not take this route because i could not find a p30, these are much easier as the drag link and steering has the same geometry as the stock axle and is almost a direct swap minus leaf springs/leaf mounting if i looked correctly but this DIY/Parts list is based of the c3500hd 10lug

    Step 4- I found that Napa auto parts still lists the king pin kits for the 1947-1954 2 ton truck its size is 1.109" its runs around $110 bucks 15345988851803457725643368343103.jpg

    Step 5- Custom king pin bushings, you guys on here helped me with this one i ended up using SAE660 Bronze but i had bought a 1 foot peice just in case my machinest messed up i gave him the kingpin and spindle he made it pretty tight it was just hard enough of a fit to barely press it in with my thumb

    Step 6- Leaf springs and shackles, They actually still make/sell these im not sure what they are put on these days but according to the leafspring shop they are easy to find I used the exact original springs and shackles design just new. They are the same part number for both sides in case you were wondering, Cost $1050. 15345989546717501016745468208197.jpg
    Step 7- Calipers/pads/rotors this stuff can be bought new and is cheap with a core. I fortuately bought a front axle that had a full brake job done so my stuffs in good shape but i still bought calipers for a C3500HD axle because of how cheap they were, This part is pretty self explanatory if you ever put brakes on a car/truck that are disc. Cost $60 for both with the cores returned

    Step 8- U bolts and brake hoses and lines. I had the original u bolts remade these are common and if you cant find them any big truck shop should be able to help they are 9/16 thread also. The Brake hoses off a p30/C3500HD should fit those new calipers as well, if we shoot over to the brake line side of things your going to need a 1/4" to 3/16" brake line adapter to go from the hardline to the hoses. Dorman makes the adapter its cheap. Cost of hoses $30, cost of the adapters $9 15345991724054440831163926503116.jpg

    Step 9- Wheel bearings, mind as well change em boys, they are about $25 a peice, again p30/c3500hd bearings for those new spindles be sure to pack them before install $100

    Step 10- Bolt the New leaf shakles/leafs in, they only go in one way so thats easy.

    Step 11-Front axle, ok so i had a part number stamped in mine that number faced towards the front bumper away from the cab, this is VERY important because the bolt pattern on the axle pad for the leaf springs is tapered and your u bolts wont fit if its in backwards, i beat the heck out of mine and found that out the hard way heres a pic of the springs they should look normal. And heres a pic of those numbers that face towards the bumper. (Disregard the shocks they are the original, and they will work mine just got completly destroyed and i need to fabricate new arms)
    15345994821545861230987026149316.jpg 15345993481043742082001725044435.jpg

    Step 12- spindle load bearings, grease these prior to insert they sit on the bottom of the inside of the spindle/kingpin. They are also labled to witch side is top and bottom

    Step 13- Put the pin,load bearing and spindle on, grease up those new wheel bearings and put those in the hub/rotor and put that all on 15345995553344793814227416802981.jpg

    Step 14- Now some might shun me for this but it was welded by a professional with an X-Ray tig welder and i know its done right some might have a big arc welder that can do this but my 110 welder WILL NOT weld 1" steel but i cut the old spindle arms to fit to the new spindle arms off the p30/c3500hd and marked them to be welded on in such a manner that the steering drag link was setup like the original and mounted under the leaf springs. Theres no science to this but when you do this IT MUST BE WELDED RIGHT! Remember we want to be safe too! if your off a little bit its OK most of it can be made up with tie rod adjustment. We went about it but having everything bolted up in the truck and mocking this up, this peice im pointing at will have to be chopped off. Since i used the C3500HD spindles i had to use the steering arms off it because the original ones off my 1952 chevy woundnt fit the new spindles hence why we cut the important bits off and welded them to the news (these are old mock up pictures, theyve since been painted and professionally gone over to make sure they are safe to use) but you get the idea 15345996312454784295794128558039.jpg

    Step 15- Put the calipers in and add your wheel of choice to it. The easy way find a 19.5 10 lug chevy rim to put on there or bore the center of your original wheel to hub center it.

    Step 16- If you are having problems with youre brake balancing front to rear it might not be a bad idea to cheack the master cylinder out mayne refresh that and add an adjustable proportioning valve, all the big name car parts places sell them that are no more then $50 bucks

    Step 17- Make sure to grease everything when your done, paint those new calipers and anything else that will get rusty, once done enjoy youre vehicle. 15345999989387967074238800692424.jpg

    I will add pictures tomorrow but this is the bulk of it, i bought alot of new stuff the total cost is $2000 it might sound like alot but being able to get off the shelf parts, non widow maker wheels, the added safety overall is worth it, Good refresher for an old truck.
    Last edited: Aug 18, 2018
  2. Casey Riley
    Joined: Jun 27, 2018
    Posts: 541

    Casey Riley
    from Minnesota

    Thanks for the write up. This is what forum's are all about. I'm looking forward to the pictures.
    Pat Stephens likes this.
  3. Pat Stephens
    Joined: Jan 26, 2017
    Posts: 8

    Pat Stephens

    No problem! I know these trucks are everywhere, and no one does much with them. This one ive had kicking around for a bit i do have a rollback bed for it but decided it would be better to put the original stake flat bed on it. Maybe install a 5th wheel?
    Okie Pete likes this.
  4. David Goodwin
    Joined: Jan 10, 2022
    Posts: 1

    David Goodwin

    Pat Stephens, this is a great write up and this is exactly what I'm looking to do with my 1952 4100. But, I have a few questions before I dive in. I understand this is an old post, but I'd like to be cost efficient before I start hacking and cutting. If you don't mind, please respond. Thanks.

  5. So glad this has come up again, I missed it the first go round thanks for posting.

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