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Adjusting Hydraulic Brakes 39 Ford

Discussion in 'The Hokey Ass Message Board' started by LesIsMore, Jun 14, 2012.

  1. LesIsMore
    Joined: Apr 8, 2008
    Posts: 372

    LesIsMore
    Member
    from Ohio

    Ok, so blakes are bled, I have a pedal, but its spongy, seems the brakes need adjusting. The worm/shell gear whatever you want to call it obviously gets tighter/looser as you rotate it, however is there a good rule of thumb for how they "Should" be set? I am starting at completely free rolling, all of the way loose, i always go for the slightest drag of shoes, is this the way to go, or do you guys have some advice?

    Les
     
  2. HellRaiser
    Joined: Jun 14, 2006
    Posts: 1,240

    HellRaiser
    Member
    from Podunk, NE

    If you are using original 39 brakes, I would suggest you take the drum off one and see how they operate. I could explain it here, and I'm sure others after me will chime in and try to tell you, but once you see how they operate, then adjusting them will become a whole lot easier.


    HellRaiser
     
  3. LesIsMore
    Joined: Apr 8, 2008
    Posts: 372

    LesIsMore
    Member
    from Ohio

    I have had them all apart and rebuilt them, I am just wondering how I should adjust them, front shoe and back shoe have own adjuster, should all be loose, moderate, tight, etc. Should the front shoe or back shoe adjustmenst be equal, etc.
     
  4. Saxon
    Joined: Aug 9, 2008
    Posts: 2,011

    Saxon
    Member
    from FL

    I have to pull my drums on my truck this weekend to do what your asking.

    I like to have a slight drag, then back it off one click. You don't want them freewheeling imho.

    Also, on the later with the spoon adjuster. We always did adjustment by lifting car, spinning tire, and adjust till the shoes just started to drag. All wheels.
     
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  5. Saxon
    Joined: Aug 9, 2008
    Posts: 2,011

    Saxon
    Member
    from FL

  6. George/Maine
    Joined: Jan 6, 2011
    Posts: 956

    George/Maine
    Member

    you may want to try this way.
    Remove drum center shoes bottom equal amount,now expand to 1/8 less then drum
    12 -11 7/8 if they hit on top grind off whats in way.
    That should get you good to go close enought.
     
  7. LesIsMore
    Joined: Apr 8, 2008
    Posts: 372

    LesIsMore
    Member
    from Ohio

    Saxon,
    I do the same thing, getting it in the air seems to be best way, ok, than I have it right, have to look at lines and M/C next.
     
  8. JustplainJ
    Joined: Apr 24, 2007
    Posts: 911

    JustplainJ
    Member
    from so.cal.

    don't forget about the top adjuster's.......lots of guy's only do the bottoms.
    start with the back shoes then go to the front with slight drag at all four drums.... if pedal is still spongy you have air in sys.or another problem
    this is how I do mine pedal is very firm......
     
  9. fordor41
    Joined: Jul 2, 2008
    Posts: 635

    fordor41
    Member

    alternate between the top and bottom adjusters with some pressure on the brake pedal.
     
  10. JohnEvans
    Joined: Apr 13, 2008
    Posts: 4,853

    JohnEvans
    Member
    from Phoenix AZ

    Hate to say it ,but do a search. The 39-42 style with the bottom adjustable anchors take a very specific adjusting sequence for proper operation. And if your drums are over .040 OS and the shoes were not arced to the drum even with the correct adjustment you likely will have a spongy pedal until the shoes get seated.
     
  11. Dirty Dug
    Joined: Jan 11, 2003
    Posts: 3,207

    Dirty Dug
    Member

    I don't like bad answers. You're on the right track having them all loose. Adjust the bottoms first till they just start to resist then back off just a hair. Then adjust the tops until they do the same...You're done, further adjustments as brakes wear will be just the tops. What you have are excellent front brakes for a light hot rod. Don't ever let anyone tell you you need to upgrade to discs for better braking...
     
  12. striper
    Joined: Mar 22, 2005
    Posts: 4,430

    striper
    ALLIANCE MEMBER

    ********************** BRAKES **********************
    ‘39 THROUGH ’48 FORDS AND MERCS: These brakes were designed by
    Lockheed. Hydraulic pressure expands the wheel cylinder cups which
    push the shoes against the drum. The shoes are NOT self-energizing.
    The Lockheed system is a front/rear shoe design with the bottom pivot
    for each shoe firmly anchored to the backing plate. These require
    considerably more pedal pressure to stop than self energizing brakes
    because they rely solely on hydraulic pressure. The front shoes do
    most of the stopping and use the longer friction band. The rear shoes
    have the shorter friction band.
    ‘39-’48 LINCOLNS (and ‘49 and up Ford/Merc): These are
    manufactured by Bendix. They are self energizing (often referred to
    as duo servo) brakes. The shoes are linked to each other at the
    bottom, but are not attached to the backing plate like the Lockheed
    design. The system is a primary/secondary shoe (not forward/rear)
    design. The primary is the front shoe in all wheels. The top of the
    primary shoe is moved outward by hydraulic pressure to contact the
    drum. The rotation of the drum “wedges” against the primary shoe and
    moves it downward. Since the bottom of the shoes are not attached to
    the backing plate, this movement is transmitted through the bottom of
    the secondary shoe. This force moves the bottom of the secondary shoe
    outward where it now “wedges” into the drum. This increases braking
    and decreases brake pedal effort. This results in considerably more
    braking force than the sheer hydraulic pressure design used in the
    earlier Lockheed brakes. Since the Bendix uses self energizing
    action, the primary (front) shoe has the shorter friction band and the
    secondary (rear) shoe has the longer friction band.
    F-100 BRAKES FOR EARLY FORDS: These are Bendix brakes.
    Conversions require drums, backing plates, and hubs from a ‘53-’56
    Ford F-100. These drums use the same large bolt wheel pattern as the
    ‘40 through ‘48 Fords do. One pair of Timken 14116 inner bearings,
    one pair of CR Services 15214 oil seals, and both ‘37-’48 Ford
    spindles are needed. The ‘39 through ‘41 spindles have a round flange
    and require modifying because the wheel cylinder won’t clear the
    spindle flange. Grind off the top of the flange that interferes with
    the wheel cylinder. The ‘42-’48 spindles have a somewhat square
    flange which clears the wheel cylinder and grinding is not required.
    On both round and square flanges, the new inner bearing has a square
    shoulder which conflicts with the rounded race on the spindle. Grind
    the inside of the bearing race to round it slightly so the bearing
    will fit snugly against the spindle’s mounting face. Every thing else
    is a bolt up.
    EARLY WIRE WHEELS ON ‘40 THROUGH ’48 DRUMS: When using early
    spoke wheels, spacers are needed between the drum and the wheel
    because the early drums have a taper where the wheel meets the drum.
    The ‘40-’48 disc wheels did not have this taper. If the drums are
    bolted up without the adapter, the drum won’t be seated tight against
    2
    the drum and all force is transmitted directly to the wheel lugs...
    not a good thing.
    SQUEAKING BRAKES: Squeaking can be caused by oil or brake fluid on
    the brake linings. But squeaking can also be inadequate lubrication
    in some locations. Put a small film of grease, or a single drop of
    oil, wherever the metal part of the shoe contacts anything metallic.
    This includes; the shoe to backing plate rub points, where the
    emergency brake cable connects to the actuating arm, the emergency
    brake actuating arm pivot pin and wave washer, where the emergency
    brake cable exits the cable’s housing, the brake shoe holding pins and
    washers, and wherever the springs etc. come into contact with the shoe
    or backing plate.
    An old trick we used to use was to stretch a screen door spring
    around the brake drum to dampen drum vibrations. This worked.....
    sometimes.
    If your brakes have been in use for some time and they begin
    squeaking, try going over the linings with 80 grit sand paper to
    remove any glaze. Just scuff them enough to break the glaze.
    ************************* ADJUSTING BRAKES *********************
    ADJUSTING ANCHOR PINS ON ‘39 THROUGH ’48 FORD/MERC BRAKES: These
    are Ford Lockheed (not Bendix) brakes and use special brass washers in
    conjunction with eccentric anchor bolts to position the shoe. The top
    of the shoes are controlled by eccentric cams. The anchor bolts at
    the bottom of the backing plate control the shoe position by rotating
    eccentric washers at the bottom of the shoes. Make sure the anchor
    bolts turn freely.
    ‘39-’41: These anchor bolts have locating marks indented on the
    elongated head adjusting bolt. These anchor bolts extend through the
    backing plates and are adjusted externally after loosening their large
    external lock nuts. The elongated ¼" head has either a punched dot or
    a stamped arrow for reference when making anchor adjustments. After
    adjusting the shoes, the adjustor lock nuts are tightened without
    permitting rotation of the anchor pin adjusters.
    ‘42-’48: The anchor pins are essentially the same as the ‘39-’41
    brakes but do not have any reference marks. But, unlike the ‘39-’41
    brakes, the lock nuts are located internally on the inside of the
    backing plate. The large round bolt heads on the outside of the
    backing plate have no dots or stamped arrows, but have a plain round
    head (similar to a carriage bolt). The drum must be removed to
    loosen/tighten the anchor adjustor’s lock nut and to adjust the anchor
    pins. Removing the drums to adjust the anchors is next to impossible
    during brake shoe adjusting (the top adjusters have to be adjusted so
    the wheel cannot be turned). It’s a lot easier if a groove is ground
    across the rounded head for a bladed screwdriver. Then a screwdriver
    can be used on the outside as a substitute for the 1/4" elongated bolt
    used on “39 through ‘41 models. After adjusting, The drum has to be
    removed to tighten the anchor pins lock nuts.
    Always rotate the wheel in the same direction the wheel turns as the
    car moves forward.
    3
    (1) Slightly loosen both anchor bolt lock nuts on one wheel. On ‘39-
    ’41, turn the 1/4" adjuster so the locator marks on the two shoes face
    each other. On ‘42-’48, remove the drums and turn the anchor pins so
    the wide part of their brass washers face each other and re-install
    the brake drum.
    All further adjustments are made by turning the anchor bolt
    adjusters in a specific direction.....
    (a) The front anchor bolt adjusters on both wheels on the
    drivers side are turned counter-clockwise (looking at the back side of
    the backing plate)...... the rear anchor bolt adjusters are turned
    clockwise.
    (b) The front anchor bolt adjusters on both wheels on the
    passenger side are turned clockwise (looking at the back side of the
    backing plate)......... the rear anchor bolt adjusters are turned
    counter-clockwise.
    (2) Back off the upper 11/16" cams on both shoes until the drum turns
    freely.
    (3) Turn one of the upper adjusting 11/16" cams until the wheel
    cannot be turned. Then adjust its 1/4" anchor bolt in the correct
    direction until the wheel turns (this lowers the shoe and moves the
    toe of the shoe away from the drum which will result in fuller shoe
    contact).
    (4) Now repeat previous step (3) over and over on the same shoe until
    turning the anchor bolt will not free-up the wheel.
    (5) Back off the anchor pin very slightly until the wheel will just
    barely turn. Tighten the anchor pin lock nut and proceed to the
    backing plate’s other shoe before going on to the next wheel.
    TIP: If you’re installing new shoes which have been arc-ground
    to fit a newly turned drum, you normally won’t have to go through the
    preceding exercise. Turn the dots/arrows on ‘39-’41 models (or the
    wide part of the brass washers on ‘42-’48 models) until they’re facing
    towards each other. This correctly positions the brake shoes and you
    don’t have to go thru the anchor pin adjusting..... just adjust the
    upper 11/16" cam adjusters.
    ***************** WHEEL & MASTER CYLINDERS *****************
    WHEEL CYLINDERS ON FORD LOCKHEED BRAKES: Because these brake
    systems rely solely on hydraulic pressure to push the shoe against the
    drum, the shoes which have the longer frictional bands need more
    pressure than the shoes with the shorter amounts of frictional
    material. Most Lockheed wheel cylinders use two different sizes of
    cups. The larger size cup is for the forwardmost shoe (longest
    friction band).
    HONING: Honing wheel and/or master cylinders during rebuilding is
    critical. Use of cutting oil in place of kerosene or solvent when
    honing hydraulic cylinders will produce a superior surface in
    considerably less time. The hone scores made using cutting oil
    provide a much better sealing surface than when using solvent or
    kerosene. Be sure to thoroughly clean the cylinder after honing.
    4
    BLEEDING A REPLACEMENT MASTER CYLINDER. This is used only when
    replacing a master cylinder. Because all of the air is usually
    located at the master cylinder’s fitting connections, it will often
    bleed back into the master cylinder with a little coaxing.
    Top off the master cylinder and install the cap. Pump the brake
    pedal about 10 pumps quickly (it’ll be close to the floor). Then
    allow air to dissipate for a minute or so. Repeat another 10 pumps
    and wait. Top off the brake fluid. Repeat it once more. After the
    third time, the air should have bled off and you should have a firm
    pedal. If you don’t have a firm pedal, try it a couple more times.
    If you don’t have a firm pedal, there is air elsewhere in the system
    and you’ll have to bleed the whole car. Beats jacking up the car and
    bleeding each wheel. If you’re going to flush the system you get to
    bleed all four wheels.
    SILICONE BRAKE FLUID: Neat stuff and it doesn’t eat paint. I
    don’t use it except in something that’s primarily a show car.
    Reasoning? I find the brake pedal feels softer than when using
    regular DOT 3 brake fluid. Also, the Rocky Mountains where I live,
    have some fairly high mountain roads and passes. And for some reason
    I don’t know, frequent and/or abrupt altitude changes will often cause
    the silicone brake fluid to become somewhat cloudy because it’s
    absorbed a very minute quantity of air. This makes for a soft brake
    pedal that may go clear to the floor. After the car sits for a few
    hours, the air dissipates from the silicone and the pedal returns to
    its former status and feel. If I’m hauling it at speed into a neat
    corner (we all play don’t we?) I sure get nervous if the brake pedal
    feels spongy or like it’s going away..... my heart can’t stand too
    much excitement anymore! However, many use silicone with absolutely
    no problems. As with all this garbage, this is just my opinion.
    (From rodnut on 1/30/03: Another problem is it will damage the
    diaphragm in hydraulic brake light switches. Use a mechanical type
    brake light switch.)
    BLEEDING A DRUM/DISC BRAKE SYSTEM: If you’re running a
    combination brake system (disc front and drum rear) you’re probably
    using a proportional valve to limit hydraulic pressure to the rear
    brakes. Bleeding this type of system is different than bleeding an
    all-drum system. The proportional valve for the drums shuts down when
    it senses any pressure in excess of the proportional valve’s pressure
    setting. Consequently we can’t just have a buddy stomp on the brake
    pedal and bleed the system. Pressure brake bleeders are mostly
    limited to 15 psi to keep from activating a proportional valve or
    metering valve. If you don’t have a pressure bleeder, have your buddy
    push the brake pedal gently (like with only his big toe) so the pedal
    applies very little pressure while you bleed the system.
    SOFT BRAKE PEDAL ON A DISC/DRUM BRAKE SYSTEM: Sometimes after
    you’ve worked on either the disc or drum brakes the pedal is soft and
    feels like “it’s going away” when stopping. Scary isn’t it? The
    cause is often the rear drum brakes are out of adjustment. Especially
    5
    if you’re just converting to front disc brakes. Adjust these puppies
    fairly snug and see if it doesn’t help the pedal.
    A disc brake rubber flex hose expands considerably due to high
    hydraulic pressure unless it’s new or in top shape. Some come with
    multi-bands of steel wrapped around them to strengthen them. Have a
    buddy stomp on your brake pedal hard when your hand is wrapped around
    your rubber flex hose. Does it expand? One cure I use (instead of
    replacing it with another new rubber hose) is to use a steel braided
    flex hose. These are usually cheaper than a stock Ford rubber flex
    hose and help firm the brake pedal.
    ************************** BRAKE DRUMS *************************
    PULLING A BRAKE DRUM WHEN A PULLER IS NOT AVAILABLE. These can
    try the patience of any man. The following is certainly not intended
    to replace a correct puller, but it’s saved me several times when the
    correct tools weren’t available.
    I use a bumper jack and the weight of the car to help break the drum
    loose. Let’s say you want to pull the right brake drum. Get the car
    on a reasonably level surface and block both ends of both front wheels
    to prevent forward or backward motion. Release the emergency brake
    and take it out of gear. Leave the right side wheel bolted to the
    drum and remove the right axle nut and washer. Invert the nut and put
    it back on the axle sans washer (don’t want to pound on the
    castellated part) until it’s flush with the axle end. Jack up the
    left rear side of the car with a bumper jack. Get it high enough so
    the left rear wheel is off the ground a few inches. Grab a hand
    sledge hammer (to persuade the drum to loosen). Go back to the right
    rear wheel. Plant your butt against the fender or body and lean
    against the car. Lean hard enough so it feels like it’s about to rock
    off the bumper jack. Then hit the axle nut a few times while you’re
    leaning hard against the car. The tipping weight of the car pulls
    against the right wheel that is still on the ground. The drum will
    usually come loose after only a few healthy swings. And if the
    flathead gods are smiling down on you, you didn’t damage the axle
    threads so bad that a couple of swipes with a file won’t cure.
    INSTALLING AN EARLY REAR BRAKE DRUM: When installing a rear brake
    drum on a ‘48 and older car, wipe a light coat of anti-seize compound
    on both the axle taper and the key. This makes future drum removals a
    lot easier. Tightening the axle nut is covered in the GEAR SECTION of
    this garbage pile
     
  13. striper
    Joined: Mar 22, 2005
    Posts: 4,430

    striper
    ALLIANCE MEMBER

    The above, as far as I know, is courtesy of Bruce Lancaster.

    Pete
     
  14. nailhead29A
    Joined: Sep 11, 2010
    Posts: 906

    nailhead29A
    Member

    Holy shit Striper thats a 101 on Ford brakes, just putting a set in my car at the moment so that info couldn't have come at a better time.
    Thanks for posting:)
     

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