Trouble adjusting rear brake shoes on 51 pacemaker.

Rob FayetteRob Fayette Posts: 110Expert Adviser
I don't know where to begin really.  I installed everything new for the brake system on this car.  I got it all together and it seemed to be working great.  Lots of solid pedal and it seemed to brake just fine. A few days later I noticed a smell like something hot or burnt when I came home from a 10 mile drive on the freeway. I took it for another drive and had my temp gun ready to lay under the car and measure the drum. The outer surface of the drum read 500 deg F . I took the drum off and the front brake shoe is worn significantly on both ends of the lining. I discovered that where the top of the shoe hugs the anchor pin it was raised up away from the pin maybe 1/8" or so. I decided to try to do a major brake adjustment where you loosen the anchor bolt.  Here is where things went sideways.  I loosened the anchor bolt about a turn to see how far up and down it would move in the slot.  It hardly moved so I loosened it some more and I got it to moving maybe 1/8 " up and down in the slot.  I thought, I will take the bolt off and clean everything up real well so it will slide better during the major brake adjustment.  I started taking the anchor bolt all the way off and it turned very hard. I kept turning and it didn't get any easier. (maybe it isn't supposed to come off?)  Then I realized that I may have damaged something where it goes through the slot in the backing plate.  Now it only moves up and down maybe 1/32 ".  I thought, well I will just change out the backing plate with a different one ,until I realized the backing plate is riveted to the axle housing.  Am I hosed?  Do I need a different rear end now? I guess this is what can happen when an amateur gets in over his head.  Thanks, as always, for any thoughts on this.

Rob

Comments

  • Uncle JoshUncle Josh Posts: 2,641Senior Contributor
    You're on to the problem.  You've got Ford shoes on there and they need the anchor pin to be moved to fit them.  Did the nut screw all the way off and did you remove the lock-washer and special washer, and remove the pin?  You will have to grind the opening to let the pin move enough.  Then you tighten the shoes with the e-brake and tap the pin until it matches the shoes per Walt Mordenti's instructions. 
  • Rob FayetteRob Fayette Posts: 110Expert Adviser
    Thanks a lot Uncle Josh.  If I understand you right the pin will come off so I will try again today.  It was turning so hard I thought I might be ruining it.
  • Ken U-TxKen U-Tx Posts: 3,890Senior Contributor
    The exposed threads on the anchor pin bolt were probably slightly buggered and rusty.....Try spraying with a good penetrating oil and let set for awhile, then first tighten back up, spray a bit more penetrating oil, then loosen the nut and get it off then the anchor pin and nut come out. while they are out, go over them with a thread chaser die and tap to clean the threads up before reusing them.
  • Ken U-TxKen U-Tx Posts: 3,890Senior Contributor
    If I read your original post correctly, you are saying the problem is with the rear shoes only, and there is excess wear on the top and bottom of the linings of the shoes that were in front? Your are aware that in the Bendix Duo-Servo brakes, the front shoe is the secondary shoe with a shorter lining than the rear shoe, which is the primary and this has a longer lining? Perhaps you put the primary shoe in front by mistake? Also, the newly relined shoes should be arc ground to match the drum they are going into.....the fact this shoe is wearing at top and bottom indicates the arc of the shoe is significantly larger than the drum, and it needs to  be arc ground to match the drum.
  • Rob FayetteRob Fayette Posts: 110Expert Adviser
    Yes Uncle Josh, I did get the pin off.  I also found the directions in Walt Mordentis' Hudson Tech Tips Volume 2: 2004-2007 page 15 where he tells how to grind the anchor pin slot .050" at the bottom; so that  today's brake shoes for Hudsons  will work.  (I think the reason the anchor pin nut was so hard to get off was because someone had put lock tight on it).

    Ken, All of the brake shoes I got off Ebay were the same size lining.  They didn't have the short and long lining like they should have. After 250 miles on them, the front shoe was worn so bad it rocked like a rocking horse when held up against the drum. The rear shoe still fit the drum perfectly. I don't know why this happened but it was causing the drum to be 500 hundred degrees when the car was being driven.

    I am going to try a different approach for now.  I found some good looking used shoes in my stash of used parts.  I believe they are the correct shoes.  I am going to try them before I grind the slots to fit modern shoes.

    Thanks for the help
    Rob
  • 54coupe54coupe Posts: 331Member
    I set the new shoes against the inside of the drum, and see if they match the radius of the drum. They may need to be re-arced to match the drum. This is a key step to having proper functioning brakes. 
  • GlowplugGlowplug Posts: 1,962Expert Adviser
    Glad to know you are headed for the home stretch Rob... keep moving a bit at a time and it will all be correct soon... Ken Cates 

  • Ken U-TxKen U-Tx Posts: 3,890Senior Contributor
    I know you said you replaced everything in the brake system, but just to confirm, you did replace the wheel-cylinder at the rear drum where you had the problem with the forward shoe wearing badly? Wheel cylinders are know to get  stuck pistons, sometimes one piston moves more than the other, thus only one shoe is doing the grunt work....... Another thing is the actuating pins, if one gets cocked at an angle, that will cause uneven shoe actuation.
  • Ken U-TxKen U-Tx Posts: 3,890Senior Contributor
    If you did replace the wheel cylinders, another question: were they newly manufactured, or NOS in a dusty box from like 30+ years ago?
  • Ken U-TxKen U-Tx Posts: 3,890Senior Contributor
    How thick is the lining on these relined shoes? should not be more than 3/16". 
  • Ken U-TxKen U-Tx Posts: 3,890Senior Contributor
    BE aware that the 11-1/16" x 1-3/4" shoes used on 1937-40 Hudson Eights look very much like the rear shoes used on Stepdowns, but use a thicker 7/32" lining to fit the 11-1/16" inner diameter of the pressed steel drums used. These may fit inside the Stepdown drums, but will obviously make contact with the drum at the very top and bottom of the shoe linings as it is bigger in it's arc than the drum ID.
  • Rob FayetteRob Fayette Posts: 110Expert Adviser
    Ken, The Master Cylinder, Wheels Cylinders, and brake lines are all recently purchased new parts. I just measured the linings and they are 3/16" thick. I'm thinking more and more that the shoes just don't fit the anchor pin correctly like it shows in Walt Mordentis' tech tip ,and what Uncle Josh also pointed out. I will post here , how the used shoes turn out.  
    Thanks for all of the input.

    Rob
  • Ken U-TxKen U-Tx Posts: 3,890Senior Contributor
    The Ford shoes in question are 2-1/4" wide X 11, that can only be used on the front drums of the long wheelbase Stepdowns, and the 52 Wasp, 53-54 Super Wasps. I suppose it is possible that there are some 1-3/4" X 11 shoes with the low anchor pin notch that will make the shoes sit higher in relation to the drum.  For comparison ;



    A
  • Rob FayetteRob Fayette Posts: 110Expert Adviser
    Thanks for that Ken.  That clarifies even more the difference between the Ford shoes and the Hudson Shoes.
    Rob
  • Rob FayetteRob Fayette Posts: 110Expert Adviser
    I got the used brake shoes installed and so far they seem to be fine.  I took them for a 20 mile run on the freeway and when I got home the drums were cool to the touch as opposed to 500 deg F with the other shoes I had bought from ebay. I have plenty of solid pedal and the car stops fine.
    I did what they call a Major brake adjustment on all four wheels where you adjust the anchor pin.  The anchor pin adjustment wasn't very easy.  On a couple of the wheels it was unclear to me if I had done it right. I think they assume you have everything perfect like drums that run perfectly true. 
     I found a way to mount the rear drum on an old axle and chuck it up in the lathe . (This is the 51 hudson rear end with the tapered axle, as opposed to the Dana/Spicer). out of the 4 rear drums I checked on the lathe, the best run out I found was .0025" on one and .005" on another. One of the drums had .020" of run out. I didn't check the front drums in the lathe. I don't see how you can get .010" of clearance at each end of the shoe when you have a run out of .005".  My hunch is that it probably isn't that important as long as you have good pedal and the car stops good?
    Thanks again for everyone's input.
    Rob
  • Ken U-TxKen U-Tx Posts: 3,890Senior Contributor
    Rob, the Dana 44 rear end used by Hudson 1952-54 does still have the tapered and keyed axle shafts and use the same drums and hubs as the 1948-51 Hudsons. Run out of 0.002" is not bad, and 0.005" can be lived with, but 0.020" is not good. Most shops with a brake lathe do not have the correct arbor and taper cones to do the Stepdown and other makes with the tapered and keyed hubs. I bought the correct AAMCO arbor and cones just for this purpose to take to a local shop should I need a tapered and keyed hub turned. I do not recommend turning a 11" Stepdown drum any more than 1/16" oversize, even though others here on the forum will tell you you can get away with 0.090" over. Maybe on a drive to church on Sunday/ parade car, but not on one you will be driving on the interstates at 70 mph. The thinner the metal, the less ability the drum has to absorb and dissipate the heat energy without going out of round.
  • Rob FayetteRob Fayette Posts: 110Expert Adviser
    Thanks for the good input Ken.  As you can see I have a lot to learn! If I remember right the guy  that did my drums said he took them to the limit.  I think he said .060" as you said.  He didn't have the correct cones for the Hudson drum.  I remember thinking at the time that it looked pretty marginal.  The one tapered cone just barely entered the small hole of the drum. It seemed like it might have been touching the edge of the hole where it wasn't really a machined surface.
    Rob
  • Ken U-TxKen U-Tx Posts: 3,890Senior Contributor
    I have this abor and cones from AAMCO 
  • Rob FayetteRob Fayette Posts: 110Expert Adviser
    Very cool Ken,  I bet there aren't very many of those around.

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