Fun and games with Bendix-10 ABS on '93 minivan

Discussion in 'General Motoring' started by velobard, Mar 21, 2007.

  1. velobard

    velobard Guest

    I picked up a '93 Plymouth Grand Voyager only to learn I was
    subjecting myself to a mess with a Bendix-10 system that's acting up.
    I've been doing a little reading on it here and elsewhere over the
    past couple of days.

    The system is apparently leaking down somewhere because I can hear the
    pump motor cycle for a few seconds everytime I press on the brake
    pedal and occasionally on its own while I'm driving. The brake light
    is on and the ABS light is apparently burned out or removed. You can
    see tape residue where they used to have tape over the ABS light.

    First off, is there any way for me to determine if the leak is coming
    from the accumulator or the piston? Is there anywhere else the ABS
    system could be losing pressure? I know the pump and piston are
    covered under the lifetime recall warranty, but I'm willing to bet any
    dealer would want to blame the accumulator first since they can make
    some money on that part. Also, as I understand it, a dealer will
    charge the diagnostic fee for checking this out but they have to
    refund it if the only problem is related to the recall. This is a
    concern because the 2 dealers I called so far was $85-110 just to hook
    up their scan tool for codes.

    Also, I notice that the accumulator is virtually the same as the one
    on my '90 Olds. I'm retiring that car and the accumulator was replaced
    it in a few years ago. I'm tempted to try swapping it onto the minivan
    to see if that helps.

    I appreciate any advice anyone can offer. If worse comes to worse I'm
    considering following some info I found elsewhere and converting it to
    non-ABS. My main goal at the moment is to see if there's a way to
    locate the source of the pressure leak on my own, or at least to
    eliminate any specific sources.

    velobard, Mar 21, 2007
  2. velobard

    kmatheson Guest

    There were many posts regarding ABS systems on this site back in the
    early to mid-1990's

    There were one or more recalls on these early ABS systems.

    Hopefully, the previous owner(s) had them done. I would suggest
    entering the last 8 digits of your VIN into the "owners" section on
    Chryser's website, so see if there are any remaining recalls.

    Glenn, it seems like you addressed this topic just a few weeks ago,
    and said that the accumulator was not covered under the recall.

    kmatheson, Mar 21, 2007
  3. velobard

    velobard Guest

    Yes, I spent a fair bit of time reading those older posts.
    This is why I want to see if I can determine whether it's the
    accumulator leaking, the piston, or somewhere else. I do understand
    that the accumulator is not covered. I can't help but feel that
    Chrysler felt like they dodged a bullet by not having that included in
    the recall, since apparently they were fairly prone to failure as
    well. If nothing else, it gave them a scapegoat they could charge for
    when minvans came in for recall warranty repairs. From what I
    understand and have read, even if the recall work was done previously
    there's no guarantee the same problem won't develop again. Some people
    who made posts in the archives made repairs done multiple times.

    velobard, Mar 21, 2007
  4. velobard

    maxpower Guest

    The accumulator is not covered

    maxpower, Mar 21, 2007
  5. velobard

    velobard Guest

    I understand that, I tried to communicate that in both my previous
    posts. That is why I want to know if there's a way for me to determine
    whether it's the accumulator or something else such as the piston
    (which is covered).
    velobard, Mar 21, 2007
  6. velobard

    maxpower Guest

    What you are describing right now is a faulty accumulator. When the pump
    charges up the accumulator, it stores pressure of 2100 psi which should give
    you at least 3 to 4 pumps of the brake pedal before the pressure drops to
    1600 psi and acitvates the pump to recharge. If the accumulator is bad one
    pump of the pedal will drop the below 1600 psi , turnign on the pump and
    possibly the red ABS lite.. If it were the pump that were bad (and it could
    go out next because the accumulator is going to wear the pump out) the red
    lite would never go out because the pressure would not reach the specified
    pressure to turn it out.
    Just from what you are telling me here . going to blame the
    accumulator due to the symptoms you describe
    Take it to an after market shop and have them try to diagnois it and see
    what they sell you. Then when they cant fix it watch how fast they blow you
    off to the dealer. And there is more to it then just hooking up a scan tool
    and getting fault codes. a special pressure gauge has to be connected to
    read the pressures of the pump and piston side of the Hydraulic assembly
    which includes depressurizing the system and remove the pressure side hose.

    good luck with that

    Dave, not a good vehicle to put alot of parts on for the brake system..Parts
    for this system are getting hard to find and Chrysler has made it almost
    impossible to get parts for this system and the ones they do have will cost
    you some ridiculous price. I beleive they want these cars going to the
    salvage yard so the recall will not bite them anymore. that accumulator i
    think is over $300, the dual function pressure switch that controls the
    pump was $53 and now I think is $175.
    maxpower, Mar 21, 2007
  7. velobard

    velobard Guest

    Thank you! I've decided that I'll try going to a pick & pull yard
    tomorrow and take a shot (yes, I understand it's a crap shoot on these
    things) at getting a good accumulator.

    I don't plan on sinking a bunch of money into this van and if I
    determine that it's a money pit it I'll get rid of it. Thank goodness
    I don't have much in it to begin with. My next contract job won't
    start for a few weeks while I wait for a security clearance check, so
    I have some time I can invest. I might as well use some of it to see
    whether I can get this thing road-worthy. Perhaps I should also look
    for another dual function pressure switch while I'm at the yard, since
    it appears that's not covered under the warranty either. The only
    manual I have is Haynes and it doesn't show that switch. Can you give
    me some hints on locating it?

    velobard, Mar 21, 2007
  8. velobard

    kmatheson Guest

    Glenn, what year did Chrysler move off of this Bendix system, and what
    are they using now?

    Just curious.

    kmatheson, Mar 21, 2007
  9. velobard

    velobard Guest

    Well now, that does make things more interesting doesnt' it, LOL. From
    the symptoms I've described, does it sound like this could be a
    culprit in my situation? Regardless, I'm sure I won't have the
    required socket in time for this particular trip to the junkyard. I
    suppose if it looks like I'm going to need it I could yank the whole
    master cylinder because it sounds like I'd get the switch along with
    everything else.

    For tomorrow I'll just go in and pull an accumulator. It should be a
    quick trip.

    I appreciate the help max.

    velobard, Mar 21, 2007
  10. velobard

    velobard Guest

    I know from what I was reading last night that '93 was the last year
    for the Bendix-10 system in the minivans.

    If they didn't use the pump motor to pressurize the brakes, I'd look
    for a way around the ABS. As it is, if I don't fix this then the motor
    is bound to wear out prematurely. I may still use the guidelines I
    found on another forum to convert to non-ABS, or I may just decide to
    sell the whole thing.

    velobard, Mar 21, 2007
  11. velobard

    maxpower Guest

    The dual function pressure switch is located on the very bottom of the
    hydraulic assembly. it has to be removed while the vehicle is in the air
    with a special socket, It has 3 wires going to it
    maxpower, Mar 22, 2007
  12. velobard

    velobard Guest

    velobard, Mar 22, 2007
  13. velobard

    maxpower Guest

    as I said, don't put alot of money in it, im sure the salvage yards aren't
    giving them away. if the unit is already off you can get the switch off

    maxpower, Mar 22, 2007
  14. velobard

    maxpower Guest

    Just curious, what are the guidelines you see
    maxpower, Mar 22, 2007
  15. velobard

    maxpower Guest

    Anytime you use a system that constantly maintains a pressure of 2000 psi
    at ALL time you are asking for problems (such as the Bendix 10 ) Bendix 4
    for something like pressure on demand.

    maxpower, Mar 22, 2007
  16. If you are handy the smartest thing you can do is pull out all that ABS
    crap and make it a standard brake system. You should be able to get
    the parts from a wrecker. The Bendix-10 system is horrible I never
    heard one good word from any Chrysler mechanic about it - and when
    I was shopping for a used van several years ago my brother in law who
    is a certified mechanic for a Dodge dealer warned me not to touch one of
    those. And I myself am handy with tools.

    ABS only works in limited circumstances anyway. If your barreling
    down a road covered with ice or gravel ABS won't do squat. I've
    tested it under controlled conditions with my 95 van which has the
    ABS bendix 4 system. About the only thing it will do for you is help
    in rainy weather - and if you are speeding in the rain you probably
    deserve to smash up anyway.

    Ted Mittelstaedt, Mar 22, 2007
  17. Dave could you post these I do not have an allpar account and since it
    to be some sort of bulletin board forum those instructions probably will not
    very long. If you post it here it will go into the google archives.

    Ted Mittelstaedt, Mar 22, 2007
  18. velobard

    velobard Guest

    No problem. Special thanks go to Fabinator on Allpar. He posted these
    in a couple of the Allpar forums, this one was from 1/30/07.

    I have a '91 Imperial with the Bendix 10 ABS system, this brake setup
    came in many cars and vans from the early to mid '90s. The interesting
    but somewhat short-sighted idea of electric-assist brakes instead of
    vacuum-assist brakes are the main problem. The hydraulic pump tends to
    die, and teh accumulator which stores pressure tends to leak... not to
    mention frequent and costly computer related failures.

    A class-action lawsuit against Chrysler mandated free replacement of
    the pump motor and accumulator for the life of the vehicle, but the
    brakes still suck. I have sucessfully converted my Imperial to vacuum-
    boosted brakes, without the ABS feature (good ridance). Here's how I
    did it, and how much it cost.

    You will need:

    One vacuum booster from an '88-'93 Dynasty or New Yorker

    One master cylinder from same vehicle (you could use any MC that fits
    onto the booster, just get the brake line fittings with it

    One proportioning valve to match the vehicle (for the Imperial, use
    one from a 4-wheel disc car. Vans will need one from a similar van).
    The proportioning valve is NOT optional, the Bendix 10 system is not
    equipped with an external unit.

    The brake pedal from the same car you got the booster from (ABS uses a
    different size pushrod from the pedal arm to the booster/control unit)

    All the fittings from the prop valve to the brake lines, and the two
    small lines from the prop valve to the MC.

    Check your intake manifold to see if it has a free 3/8" fitting with a
    cap on it. If it doesn't you'll need one from the junkyard.

    One quart of brake fluid (I flushed the entire system with less than a

    A double-flare tool, taht can flare 3/16" tubing

    Small tubing cutter

    10" crescent wrench, 11mm wrench, 13mm wrench, 15mm wrench, 17mm
    wrench, 18mm wrench, heavy duty cutters (for cutting brake lines),
    socket wrench, 3" extention, 13mm deep socket, 15mm standard socket,
    3/8" standard socket... this is what is needed if you use the MC from
    an '88-93 Dynasty or New Yorker, using a bigger MC off of a D-150
    truck may require other tools. Due to the fact I may have forgotten
    something, and you (or me) may have an odd car, bring a good variety
    of tools.

    Phase 1: gathering the parts

    the first thing to do is get the pedal off of the donor vehicle, it's
    much easier to remove the booster once the pedal is out of the way. To
    do this, remove the under-dash panel (the black plastic one, not the
    one that matches the interior), use the crescent wrench to grab the
    end of the pivot rod for the pedal arm (it's the one on the driver's
    side, then use the 15mm socket and ratchet to remove the nut on the
    pivot rod. After the nut is removed, the rod will slide out toward the
    driver's side. remove the clip holding the booster pushrod to the
    pedal arm, and the pedal should be free.

    Step 2: Remove the master cylinder. Undo the two brake lines from the
    driver's side of the car with the 11mm wrench, then unbolt the MC from
    the booster using the 13mm socket, or 13mm wrench. It should now be

    Step 3: remove the booster. You will need to remove all vacuum lines
    from the booster, but you may want to save the booster-to-manifold
    line. I used new 3/8" oil cooler line. If you need the vacuum fitting
    for the intake manifold, grab it. Once the MC and brake pedal are
    removed, it's held to the car with four 13mm nuts from inside. Remeve
    them starting with the one at the upper passenger-side corner, it's
    the hardest one, get it with the 13mm wrench. All the other nust are
    easily accessible, the lower passenger-side nut is easiest to get with
    the wrench. The lower driver's-side nut is easiest with the 13mm
    socket and 3" extension, the upper driver's-side nut is easiest with
    the 13mm socket w/o extension. The booster should now be free, pull it
    out from the front.

    Step 4: remove the proportioning valve. Before you dig in, note where
    the brake lines go... the driver
    s side front goes to the front front fitting, front passenger side
    gors to the rear fitting, and the rear lines go to the bottom... not
    sure which way, but also not sure if it matters too much (I matched
    the orientation to my Dynasty). Unbolt the prop valve from the
    bracket, and cut the lines to the calipers a couple inches from the
    prop valve. Leave the lines to the MC intact. Remove the prop valve

    You're done here, go back home.

    Phase 2: Gutting your vehicle

    Everything comes out. Remove the brake pedal, master control module
    (Bendix 10 equivalent to master cylinder), and the pump assembly. The
    MCM is attatched to the firewall in the same way, but it has four
    lines coming off of it, instead of two... this is why you needed the
    prop valve. The lines are in different areas, some hard to reach. You
    will also need to disconnect a whole lot of electrical connectors.
    Once you have it out, do what you want with it. You may need to save
    the caps... the MC I got had none.

    the pump motor is attatched to the car at three points: two bolts into
    the top of the diff cover, one bigger bolt goes to the bell housing.
    Remove the heat shield with the 3/8" socket first.

    Phase 3: fitting and installing parts

    The first thing do do would be to trim the brake lines, install the
    proper fittings, and re-flare the ends. Once you have this done,
    install the prop valve bracket. Attatch the lines to the prop valve,
    and bolt the prop valve to the bracket. That part is done.

    The booster is different from the ABS MCM, so you'll need to cut the
    rubber thing in the firewall out of the way. Install the booster, and
    hool up the vacuum line. My car had the heater control line on the
    manifold, leave it there. If your car needs the extra fitting install
    it now.

    Install the non-ABS brake pedal, and transfer the pad if you want. My
    Imperial had stainless trim on the pedal pads, and the donor car did
    not... that's why I transferred the pad.

    Install the MC and begin to thread the brake line fittings... you need
    to bleed the MC a little before you tighten them all the way. Fill the
    MC, and slowly pump the pedal once. If you can see brake fluid
    dripping from the fittings, tighten them up... if not, either the
    fittings were too tight, or you need to pump the pedal again.

    Bleed the lines. Start with the left-rear wheel, go to the right-rear,
    then the left-front, and finally the right-front. Keep the MC res
    topped off, you don't want to start pushing air int the lines.

    I think you're done, leave some nice tire marks.

    This took me four hours at my house, and 1.5 hours at the junkyard.
    The booster cost $15, the MC cost $5, the prop valve cost $10, the
    pedal cost $6, and the brake fluid cost $7. the brake lines were so
    short, they didn't charge for them.

    An easy day's work, and less than fifty bucks may just save your life
    later. Sounds like a good deal to me. I don't know how to post this in
    a "more permanent" reference or archive section. If a mod could put
    this post somewhere more useful, please do... also feel free to modify
    anything, or add to it. If anybody wants more detailed information,
    let me know what, and I'll post it. I'll be posting pictures on my
    cardomain site soon, I'll post here when they're up.
    velobard, Mar 22, 2007
  19. velobard

    Bill Putney Guest

    Hah hah! That's stickin' it to the man! I love solutions like that.

    Bill Putney
    (To reply by e-mail, replace the last letter of the alphabet in my
    address with the letter 'x')
    Bill Putney, Mar 22, 2007
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