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Buick Brake Drum Tech

Discussion in 'The Hokey Ass Message Board' started by gashog, Jul 26, 2006.

  1. gashog
    Joined: Dec 9, 2005
    Posts: 978

    gashog
    Member

    Buick Brake Tech

    There is a ton of good stuff on the HAMB about Buick drum/hydraulic brakes but no single post on the complete conversion. I just finished up the front brakes on my 29 and figured I would do a write-up on the “how to” and parts I used to tie it all together. I apologize for having links to some of the pictures, but their is a 20 picture limit on posts.

    Unless you are prepared for a lot of headaches and stuff that doesn’t fit together, an old Wagner or Bendix brake parts interchange manual is a must have. I started with a set of 45-fin Buick 12” aluminum drums from a 1964 LeSabre, a set of 1953-56 F250 backing plates, early Ford 1943-45 juice hubs that mount on the INSIDE of the drums, and 1935/36 spindles and axle. The 45 fin aluminum drums were used in big Buicks from 1957-64. The F250 backing plates are the Bendix floating/self adjusting design similar to the hard to find Lincoln backing plates, a huge improvement over the 1939-48 Ford-Lockheed brakes. I went with the 1943-45 hubs because I planned to run 16” smoothy rims with a 5 x 5 ½” bolt pattern. There is a little less machining if you use the later 1946-48 hubs instead of the early Ford 1939-42 drums/hubs. I considered using my original Model A hubs but never heard of anyone using them and given the low speed design of these cars, I didn’t want to be the first to try. I picked up 1935/36 spindles/axle as cheap way to lower the front end of the Model A with the stock 2” drop axle.

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    http://www.sunbunnybrown.com/detailshop/HAMB/spindle.jpg

    In addition to the 1964 LeSabre drums I was using for the conversion I also had a 1960 Invicta drum. They are the same thickness, diameter and have the same size hub register hole, but there are subtle differences between the early and late Buick drums. The LeSabre drums had balance weights and the Invicta drum did not. The machined area for the hub on the inside of the drum is about 1/8" smaller in diameter on the early drum and may require machining a little too close to the bolt circle for inside the drum hubs. There are also several differences between the two drums to accommodate the linings used in the two cars. The 1964 LeSabre drum has a 2 ½” wide machined surface to accommodate 2 ¼” wide shoes and the lining contact surface is recessed ½” from the back of the drum. The Invicta drum has a 2 ¾” wide machined surface to accommodate 2 ½” wide shoes and the lining contact surface is recessed ¼” from the back of the drum. Using the early drums will effectively move the drums inboard, a clever way to avoid spacers that may be needed to bring the linings in full contact with the drums for certain combinations of backing plates and spindles.

    I drilled out the rivets on the Buick drums and knocked out the studs on the Ford drums to separate the drums and hubs. Be careful to support the backside of the Ford hubs when you knock out the studs so you don’t bend the mounting flanges!

    A buddy of mine did the machine work to register the Buick drums to the Ford hubs. He had hoped to find a chunk of pipe that was close to the right size to make the job a little easier but ended up using aluminum stock. The drums should be registered to the hubs, NOT the studs, so you don’t need to be concerned about the orientation of the drums and the hubs in the future.

    After cleaning up the snouts on the Ford hubs, he bored a hole in the aluminum stock for a light press fit on the hubs, then turned the ODs for a tight slip fit to the holes in the Buick drums. He trued up the mating surfaces of the Buick drums and the Ford hubs and turned the OD of the hub flanges to fit the recesses on the inside of the Buick drums. The register rings were installed with Loctite Spherical Parts Locker. I am running 16” steelie wheels so I wanted to keep the 5 ½” Ford bolt pattern. Pilot holes were drilled in the Buick drums to match the pattern with the final sizing waiting until the studs were installed so the holes could be machined for a nice slip fit.

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    http://www.sunbunnybrown.com/detailshop/HAMB/hubBack.jpg

    I had used a BFH to knock out the Ford studs and the Buick drums were ~3/16” thicker than the original Ford drums so new longer studs were needed. I have seen suggestions to use NAPA 6411145, 6411138 or Dorman 610-132 studs. At 1 29/64” overall, the NAPA 6411145 may be a little short for good lug engagement, and all of these studs are larger in diameter than the originals and require machining the holes in the hubs. You can get original style studs from Mac’s for about a buck and a half (Mac’s 68-1107). At 1.56” overall (original studs were ~1 3/8” overall), the studs were plenty long to use with the Buick drums (six full threads of engagement with 16” Ford rims). They were a little loose in hub bores so we knurled them and installed them with Loctite Spherical Parts Locker. After the studs were installed, the holes in the drums were machined to their final size.

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    http://www.sunbunnybrown.com/detailshop/HAMB/assy.jpg

    Speedway and Mac’s sell kits that include backing plate centering rings and spindle shaft spacers for mounting juice backing plates to early mechanical brake spindles (Speedway # 91631928 @$19.95 and Mac's #X-2000 @$17.95). I have been told that you can use Model A piston rings and valve seats but decided to spring for the $20 kit.

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    As it turned out, the spacers were not needed with the 1935/36 spindles I was using, 1937-41, round back or 1942-48 rectangular back spindles. Spacers or shortening the backs of the hubs would be needed with Model A spindles and the nearly identical 1932-34 spindles so the hubs do not bottom out against the backing plates. The rear bearings in the 1943-48 hubs are recessed ~3/8” and the rear bearing surface of Model A and 32-34 spindles is ~5/16” inboard compared to 1936-48 spindles. Careful measurements and the appropriate spacers/machining are needed with these spindles to ensure that the shoes are in full contact with the drums.

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    The F250 backing plate/spindle bolt pattern did not quite line up, a problem if you are using any 1928-36 spindles with 3/8” backing plate bolts (early Ford 1939-48, Lincoln and F250 backing plates all use the later 1937-48 bolt pattern with larger ½” bolts). I slotted the holes in the backing plates and grease shields, and bolted them to the spindles with new 3/8” fine thread bolts and self locking nuts. I used flat washers on the hub side of the backing plate to retain the centering rings. The hubs were installed with new bearings, races and seals (same for all Ford 1928-48) also available from Mac’s.

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    http://www.sunbunnybrown.com/detailshop/HAMB/BPslots.jpg

    http://www.sunbunnybrown.com/detailshop/HAMB/BPbolts.jpg

    The F250 backing plates use single-sided wheel cylinders but are easily converted to dual cylinders by drilling an additional mounting hole. Most folks use F100 cylinders (1 1/16” Wagner #F41718/F41719). I did a little poking around on the Bendix website and found some whopping big 1 3/16” cylinders from a 1992 F250 Supercab that were a direct drop in for the backing plates. The bigger cylinders provide a little extra hydraulic force to the front wheels and the only difference was that they used a smaller 3/8” fitting instead of the typical 7/16.

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    I wanted to take full advantage of the F250’s Bendix brake design and robbed the adjusting hardware from the rear of the 1964 LeSabre 45 fin drum donor. You can also use the rear hardware from a 1971-76 Caprice Wagon with 12” drum brakes that is still available from GM.

    Things started to get tricky when I looked into the brakes shoes. Not taking the steps to ensure correct relationship between the brake linings and the drums has undoubtedly been the cause of many poor performing conversions. Mismatched spindles, spacers, backing plates and hubs could leave you with less than 1” of usable lining width!

    The stock F250 backing plates used 2” wide shoes but the Buick drums can handle up to 2 1/2” linings. I mocked up the 2 ¼” and 2 ½” Buick brakes and the half round cutouts at the top of the shoes were machined differently throwing the shoes way off center (the Buick pivot pins are ~1/4” closer to the edge of the backing plates). I try to avoid modifications to service parts whenever possible and went with the 2” F250 shoes so I wouldn’t have to machine the critical pivot pin radius. I drilled 9/32” diameter holes in the bottoms of the shoes for the Bendix self adjuster springs and tweaked the slots in the shoes to improve the fit of the self adjusters.

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    http://www.sunbunnybrown.com/detailshop/HAMB/brakeAssy.jpg

    If you have your heart set on the larger 2 ¼” and 2 ½” shoes, it might be easier to modify a set of the early Buick 12” backing plates. You can get the spacers you need for the swap from Mecutem on the HAMB and has Pete Smythe psmythe@patrons.com has adapters and machined Buick backing plates for $200 plus shipping. Lots of good info in this thread:
    http://www.jalopyjournal.com/forum/showthread.php?t=4882&&showall=1

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    The outer lips of the F250 backing plates are ~3/8” wider in diameter than the 1939-48 Ford and Lincoln parts, and just fit inside the grooves on the backsides of the Buick drums. Keeping with my philosophy of avoiding modifications to service parts, I used a 4 1/2" electric angle grinder with a grinding wheel and thinned the lip by carefully removing ~1/16” from the inner edges of the outer lips of the backing plates for better clearance in the grooves on the backsides of the drums. I also machined an access hole for the self adjuster of the left hand backing plate. The F250 plates are not left and right and a new hole was needed to line up with the star wheel of the adjuster.

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    http://www.sunbunnybrown.com/detailshop/HAMB/LHadjusterHole.jpg

    The early Ford juice and Lincoln backing plates require machining of the inner lips of the grooves in the Buick drums to accommodate the outer lips on these backing plates. If you are using the later 1946-48 Ford hubs that mount on the OUTSIDE of the drums, the thicker face of the Buick drums will move the drums inboard requiring a bit of machining to the top surfaces of the inner lips of the grooves in the Buick drums. If you plan to use these backing plates or hubs, you will have to mix and match these modifications so the backing plates clear the drums.

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    Careful measurements are required to ensure full contact between the linings and the drums. The offset of the F250 backing plates provides full contact between the 2” linings and the Buick drums, but this is not the case with the 1939-48 Ford backing plates. The shoe anchor pads of the early juice plates are offset ~7/16 “ inboard compared to the F250 backing plates. I have heard that some folks simply machine away a portion of the linings so the back lips of the drums don’t cut the shoes. The linings for these backing plates are only 1 ¾” wide. With a little more effort, you can correct the offset rather than sacrifice lining width.

    Using 1946-48 juice hubs that mount on the OUTSIDE of the drums will move the Buick drums inboard ~3/16”, the difference in thickness between the original Ford and Buick drums. Using the early Buick drums designed for the larger 2 ½” brakes will effectively move the drum inboard ¼” compared to the later drums designed for the 2 ¼” linings. I have not mocked up either of these combinations, but it looks like this may be all that is needed to bring the shoes into full contact with the drums. Spindle/backing plate spacers can be fabricated as needed to move the backing plates outboard. The grooves on the backside of the Buick drums will have to be machined accordingly to accommodate the offset. Measure carefully and do whatever you have to do to ensure full contact between the linings and drums for the parts you have.

    I do not have any Lincoln backing plates and can’t say how the offset of these plates affects lining/drum contact. Can somebody chime in on this?

    Here are a couple shots of how everything went together. About ¾” of the finned drum is visible beyond the inner bead of the 4” wide 16” steelie wheels.

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    http://www.sunbunnybrown.com/detailshop/HAMB/BPrearRim.jpg

    http://www.sunbunnybrown.com/detailshop/HAMB/drumOffset.jpg

    There are many combinations of spindles, hubs and backing plates that can be used for the Buick drum conversion, but just getting the pieces to bolt together doesn’t guarantee that they will function as an effective brake drum assembly. I think I have identified everything you’ll need to watch out for if you try the swap. Now if I can only get the time to slip the new axle under the A…
     
    Last edited: Dec 12, 2011
  2. hillbillyhell
    Joined: Feb 9, 2005
    Posts: 934

    hillbillyhell
    Member

    Good info here...I'm running the same backing plate/drum combo you are, but on F1 hubs 9mounted inside the drum). Glad you went to the trouble of ducumenting what shoes work, etc. Well done!
     
  3. RustyRedRam
    Joined: Jan 24, 2005
    Posts: 1,128

    RustyRedRam
    Member

    Great article! Thanks for the info and documentation.

    RRR
     
  4. thanks for doing that - I am sure I will be back to reference this - in fact I am printing it right now. Great Work.
     

  5. sodas38
    Joined: Sep 17, 2004
    Posts: 2,345

    sodas38
    Member

    The pictures are extrmemely helpful. Great tech piece here. I will definately reference this one down the road.
     
  6. TimW
    Joined: Jun 13, 2004
    Posts: 242

    TimW
    Member
    from Kentucky

    Wow, great post! I've done several conversion's some with the early ford backing plates, some with modified buicks and mine with the original lincolns...but I learned something new today from this post! I never new that there was a shoe difference at the top where they engage the anchor pin! This pic http://members.cox.net/detailshop/HAMB/topCompare.jpg really gave me something to look out for in future swaps. Thanks for taking the time to photograph and write the tech article. I've got a set of hubs and drums ready to go for my sedan, and this will be the first time that I've used the f-250 backing plates. Thanks again, Tim
     
    oldfordtin likes this.
  7. jackandeuces
    Joined: Feb 20, 2006
    Posts: 1,004

    jackandeuces
    Member

    Gashog, great job....
     
  8. Vergil
    Joined: Dec 10, 2005
    Posts: 785

    Vergil
    Member

    Great post, lots of good info, thanks for sharing.
     
  9. VonDad
    Joined: Apr 17, 2001
    Posts: 228

    VonDad
    Member

    Fraz here, stealing his dad's account for a minute.

    First, it's Invicta. LeSabre, Invicta, Electra.

    Also, I do know that 59-60 hubs were physically larger in diameter, and the drums from those years have a larger center hole than those found on later models. If memory serves, they switched to the roller bearings used on the front of most rear-drive GM vehicles for oh, 38 or 39 years, in 1961. I swapped 64 Riviera hubs onto my 60 LeSabre to gain access to those cheaper and better roller bearings instead of the very expensive and hard to find ball bearings. I used the original drums with the new hubs. There's a good 1/4" difference between the edge of the hub and the inside of the hole in the drum.

    Probably useless info, but info nonetheless.
     
  10. Thorkle Rod
    Joined: May 24, 2006
    Posts: 1,392

    Thorkle Rod
    Member

    Lotta good stuff here. I appreciate you taking the time and putting all down in one place. Great Job.
     
  11. gashog
    Joined: Dec 9, 2005
    Posts: 978

    gashog
    Member

    Glad to help!
    It turned out to be a whole lot trickier than I was expecting to ensure that you have full contact between the linings and the drums when you get into all the combinations of spindles, backing plates and hubs- And I never even got into the aftermarket stuff!


    Thanks for the spell-check on LeSabre and Invicta. I have noted the corrections in my original post. Now that you mention it, I remember those ball bearings when I pulled the Invicta drum. I also remember the left hand spindle nut being REVERSE thread. I beat on that sucker for ten minutes before I thought to turn the wrench the other way!

    I compared my early and late drums and as near as I can tell, the castings are identical with the exception of the early drum having a wider machined surface/shallower recess to accommodate the 2 1/2" linings. Otherwise, they are the exact same thickness, diameter and have the same size hub register hole. The machined area for the hub on the inside of the drum is about 1/8" smaller in diameter on the early drum and may require machining a little too close to the bolt circle for inside the drum hubs.
     
  12. Johnny1290
    Joined: Apr 20, 2006
    Posts: 2,834

    Johnny1290
    Member

    This article makes my head swim from all the information you have posted here! No wonder it took you 6 months, with all the pictures and whatnot. Very complete, very cool of you to take the time to do! Thanks!
     
  13. ago
    Joined: Oct 12, 2005
    Posts: 2,199

    ago
    Member
    from pgh. pa.

    Good tech, I am using 66 Buick drums and backing plates with 1 3/16 cylinders. I welded an 1/8 plate to the late backing plates. and drill holes to fit 41-48 square spindles and 46-48 Ford hubs.
     

    Attached Files:

  14. lakester47
    Joined: Feb 24, 2008
    Posts: 117

    lakester47
    Member

    Excellent post, thanks for detailing this conversion so well.
     
  15. blackout
    Joined: Jul 29, 2007
    Posts: 1,269

    blackout
    Member

    Excellent post, thanks for the effort.
     
  16. yanktankdriver
    Joined: Mar 2, 2008
    Posts: 7

    yanktankdriver
    Member
    from kansas

    Hello,
    I am saving back a set of 64 LeSabre drums. The issue is, the car has got to go and I need the hubs back to roll it on and off a buddy's trailer. So I am trying to separate them but ran into some difficulty. I have ground the rivet heads off, but the drum is still stuck tight to the hub. I haven't drilled the rivets through, but there is no portoin of the heads left so I don't think they are the problem. Any ideas on removal? I have access to a shop press, but don't want to warp the drums. Thanks for any help...
     
  17. aplayer
    Joined: Dec 2, 2006
    Posts: 148

    aplayer
    Member

    Support the drum behind the rivets, with a big impact socket or something, and press out the rivets you've ground off. Then support the entire drum from the inside and press out the hub. You may want to soak the hubs overnight before pressing them out. I used an old brake rotor to support the drum as you press out the hub. It fit perfectly inside the aluminum drum.
     
  18. gashog
    Joined: Dec 9, 2005
    Posts: 978

    gashog
    Member

    Thanks for the kudos on ther post!

    Remember, Buick hubs won't work if you want to run the early Ford bolt pattern...
     
  19. Unless you re-drill them for whatever bolt pattern you want...
     
  20. 55olds88
    Joined: Jul 23, 2001
    Posts: 2,384

    55olds88
    Member

    cool, very usefull stuff have my F100 brakes and buick drums in the shed now so might need this one day, also might have to look for the Buick brake set up and go all Buick with the adaptor (good luck here in N.Z.).
     
  21. gashog
    Joined: Dec 9, 2005
    Posts: 978

    gashog
    Member

    Yup, that'll work too. All a matter of how you want to do it :)
     
  22. six pack to go
    Joined: Aug 2, 2008
    Posts: 1,938

    six pack to go
    Member
    from new jersey

    Thanx....this is why the HAMB is awesome!!! Very KQQL!! ~Eric
     
  23. gashog
    Joined: Dec 9, 2005
    Posts: 978

    gashog
    Member

    I just learned that the spindles I showed in my original post as 35/36 are actually 36 only. The two are nearly identical with rectangular backs, large backing plate centering hole and 3/8” bolt patterns. The 35's have a long shaft like the ones used on the Model A’s and 32-34s, but the 36’s have the short shaft common to the later spindles. You would need the centering ring and spacer with the 35 spindle, but only need the centering ring with the 36. I don’t have pictures of a 35 spindle but here's a photoshop to see the difference:
     

    Attached Files:

    Last edited: Jan 21, 2009
  24. pan-dragger
    Joined: Sep 13, 2006
    Posts: 3,187

    pan-dragger
    Member

    good stuff, thanks.
     
  25. Shaggy
    Joined: Mar 6, 2003
    Posts: 5,207

    Shaggy
    Member
    from Sultan, WA

    Good stuff!!
     
  26. texas rattler
    Joined: Nov 10, 2009
    Posts: 66

    texas rattler
    Member
    from texas

    hope yall can help edjamacate me .im in the middle of a swap to buick 45 fin drums to 48 ford hubs and 48 backing plates. my question is is there any reason i cant cut the center hole larger in the drum to fit the 48 hub whith out cuting the hub? this seems like it would be easy to do as i have a 16" swing on my lathe and mounting the drum would be no problem. thaks
     
  27. Gareth
    Joined: Jun 18, 2008
    Posts: 86

    Gareth
    Member
    from San Diego

    Bringing back an old and often discussed thread here, but I can't seem to find a complete answer anywhere else.
    When setting up Buick drums with 48 hubs, round back spindles and F250 backing plates, how much usually needs to be cut away from the outer dust lips on the drum? My mock up measurements are suggesting I need to remove almost 0.25" off both lip surfaces. Does this sound right?
    Other options are to remove the interfering material from the return edge on the backing plate and/or add a spacer in behind the large bearing race inside the hub. This would move the hub and drum outboard but leave the large bearing in its original position.
    Anyone used either of these methods?
     
    Last edited: Dec 12, 2012
  28. With the F-250 backing plates, if you use the '40 style hubs where the drum mounts on the outside of the hub, you should not have to trim any of the lip of the drum as shown in the attached pictures of a Buick drum on a '40 style hub.

    If you mount the drum on the inside of the '48 style hub as normally done when using the Lockheed brakes you will have trim both the aluminum and the iron drum liner and with the rough measurements I made in the past, it seemed like there was not enough metal "above" the groove to allow the depth of cut needed.

    If you compare the difference between the pieces of steel clamped to the hubs, in the the one picture, it should give you an idea of the difference in drum spacing between the the two style of hubs.
     

    Attached Files:

  29. Gareth
    Joined: Jun 18, 2008
    Posts: 86

    Gareth
    Member
    from San Diego

    Those pics are great RICH B. I agree there doesn't seem to be enough material 'above' the groove to allow a 0.25" cut which is why I was looking at other options to reduce the interference. I don't really like either of the alternates I mentioned though. I didn't have a 40 hub here to compare to a 48 so thanks for the pic.
    I'm going to track down some 40 hubs and do the swap that way.
     

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