• Ford F150 1998 4.2L Master Cylinder going?

    From UFO@techforce@nospam.gmx.com to rec.autos.tech on Wed May 27 09:47:20 2026
    From Newsgroup: rec.autos.tech


    Did the rear drums myself a yr ago, recently the wheel cylinders had to be changed,
    and Im told the front pads still are in good shape. One Rotor had to be changed because
    the truck sat for 12 yrs at a dealer and it literally fused to the hu with
    the rust...one of the rear drums
    had the same thing happen, never saw that before.

    Anyhow aside from one rear brake line going out since then, been good
    however noticed
    if I am at a light and there is a slight incline downward like at the bottom of a hill, I can geel the pedal
    slowly going down. I can pump it back up but usually it still falls and you can hear the brakes creeking
    in the front as the pads dont grip as good and the truck starts to creep forward....so Im thinking master
    cyl, as its probably the one in there since 1998. I dont think theres been
    any fluid loss, it seems full of fluid
    and topped off.

    If in neutral seems to not happen as much...today I was at Burger King and just sat there on a level area
    with my foot on the pedal and it was rock solid.

    Other thing noticed dunno if its related is the drivers side rotor (which is new) seems to vibrate when you go down
    a fairly steep hill and ride the brake down to stay in the speed limit
    posted.

    I was told that in 4wd that wheel becomes the front drive wheel, not sure is thats important or not regarding this,
    but also both front wheel bearings were replaced last yr, and that one seems to have a hard time keeping the center cap
    on for a long while. I check to see if any of the hubcaps can be pushed in after long miles of driving and that
    one is usually a little loose and would come off eventually, already lost
    (2) of them, so I was wondering if that
    means the wheel bearing on that side is a little questionable?

    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From AMuzi@am@yellowjersey.org to rec.autos.tech on Wed May 27 11:12:44 2026
    From Newsgroup: rec.autos.tech

    On 5/27/2026 8:47 AM, UFO wrote:

    Did the rear drums myself a yr ago, recently the wheel
    cylinders had to be changed,
    and Im told the front pads still are in good shape. One
    Rotor had to be changed because
    the truck sat for 12 yrs at a dealer and it literally fused
    to the hu with the rust...one of the rear drums
    had the same thing happen, never saw that before.

    Anyhow aside from one rear brake line going out since then,
    been good however noticed
    if I am at a light and there is a slight incline downward
    like at the bottom of a hill, I can geel the pedal
    slowly going down. I can pump it back up but usually it
    still falls and you can hear the brakes creeking
    in the front as the pads dont grip as good and the truck
    starts to creep forward....so Im thinking master
    cyl, as its probably the one in there since 1998. I dont
    think theres been any fluid loss, it seems full of fluid
    and topped off.

    If in neutral seems to not happen as much...today I was at
    Burger King and just sat there on a level area
    with my foot on the pedal and it was rock solid.

    Other thing noticed dunno if its related is the drivers side
    rotor (which is new) seems to vibrate when you go down
    a fairly steep hill and ride the brake down to stay in the
    speed limit posted.

    I was told that in 4wd that wheel becomes the front drive
    wheel, not sure is thats important or not regarding this,
    but also both front wheel bearings were replaced last yr,
    and that one seems to have a hard time keeping the center cap
    on for a long while. I check to see if any of the hubcaps
    can be pushed in after long miles of driving and that
    one is usually a little loose and would come off eventually,
    already lost (2) of them, so I was wondering if that
    means the wheel bearing on that side is a little questionable?

    I would look at each cylinder/piston for brake fluid leaks
    first, then lines and master cylinder. If no obvious leak
    spots are found, purge the brake fluid.

    A soft pedal indicates air in the system, and brake fluid is
    hygroscopic so moisture increases, which will cause various
    sometimes expensive problems. This is worse just sitting, as
    there is no heat to drive out moisture.

    When you do your full bleed, dark or discolored brake fluid
    will confirm that it was overdue for a purge after sitting
    12 years.
    --
    Andrew Muzi
    am@yellowjersey.org
    Open every day since 1 April, 1971
    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From UFO@techforce@nospam.gmx.com to rec.autos.tech on Wed May 27 14:31:33 2026
    From Newsgroup: rec.autos.tech

    Thanks for the comments.

    When the drivers rear wheel cylinder went,
    the brake feedline to it ruptured, and they custom made a new one
    from the "Tee" fitting on the axle, which they said is a relief pressure valve,
    is theres too much pressure thats suppose to activate I guess.

    So when I was driving with the ruptured line, lost of fluid escaped, had
    to fill the master with fluid 2 times, so its more or less had
    a fluid flush n fill.

    At some point he said there was still some air trapped in the system
    and if I drove and hit a sharp bump that could force the bubble back up into the
    master cylinder and act like a bleeding.

    When the wheel cylinders were changed the shoes on that side had some fluid
    on them
    and they said good idea to change them or they can shoot them with brake
    clean and hope for the
    best so I had them do that rather than a new set of shoes.

    One day there was smoke coming out of that wheel, it was some fluid burning off
    the shoes so took it back for a check to the same shop, he said the shoes
    were stuck
    to the drum on that side. His boss would not let him put it on the lift and open
    that side unless I paid a fee upfront, so he looked at it in the parking
    lot.

    He took a hammer and screwdriver and went under that side and banged it a
    few times
    and had me try the pedal again and it came back up and has been fixed since.

    He also may have knocked an air bubble out of that side, as a different mechanic did the
    cylinder job out of state.


    A soft pedal indicates air in the system, and brake fluid is hygroscopic
    so moisture increases, which will cause various sometimes expensive problems. This is worse just sitting, as there is no heat to drive out moisture.

    When you do your full bleed, dark or discolored brake fluid will confirm that it was overdue for a purge after sitting 12 years.

    --
    Andrew Muzi
    am@yellowjersey.org
    Open every day since 1 April, 1971

    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From AMuzi@am@yellowjersey.org to rec.autos.tech on Wed May 27 13:42:23 2026
    From Newsgroup: rec.autos.tech

    On 5/27/2026 1:31 PM, UFO wrote:
    Thanks for the comments.

    When the drivers rear wheel cylinder went,
    the brake feedline to it ruptured, and they custom made a
    new one
    from the "Tee" fitting on the axle, which they said is a
    relief pressure valve,
    is theres too much pressure thats suppose to activate I guess.

    So when I was driving with the ruptured line, lost of fluid
    escaped, had
    to fill the master with fluid 2 times, so its more or less had
    a fluid flush n fill.

    At some point he said there was still some air trapped in
    the system
    and if I drove and hit a sharp bump that could force the
    bubble back up into the
    master cylinder and act like a bleeding.

    When the wheel cylinders were changed the shoes on that side
    had some fluid on them
    and they said good idea to change them or they can shoot
    them with brake clean and hope for the
    best so I had them do that rather than a new set of shoes.

    One day there was smoke coming out of that wheel, it was
    some fluid burning off
    the shoes so took it back for a check to the same shop, he
    said the shoes were stuck
    to the drum on that side. His boss would not let him put it
    on the lift and open
    that side unless I paid a fee upfront, so he looked at it in
    the parking lot.

    He took a hammer and screwdriver and went under that side
    and banged it a few times
    and had me try the pedal again and it came back up and has
    been fixed since.

    He also may have knocked an air bubble out of that side, as
    a different mechanic did the
    cylinder job out of state.


    A soft pedal indicates air in the system, and brake fluid
    is hygroscopic so moisture increases, which will cause
    various sometimes expensive problems. This is worse just
    sitting, as there is no heat to drive out moisture.

    When you do your full bleed, dark or discolored brake
    fluid will confirm that it was overdue for a purge after
    sitting 12 years.

    --
    Andrew Muzi
    am@yellowjersey.org
    Open every day since 1 April, 1971


    I would still do a full brake fluid purge on any vehicle
    which was parked for that long an interval.
    --
    Andrew Muzi
    am@yellowjersey.org
    Open every day since 1 April, 1971
    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Paul in Houston TX@Paul@Houston.Texas to rec.autos.tech on Wed May 27 18:56:04 2026
    From Newsgroup: rec.autos.tech

    UFO wrote:

    Did the rear drums myself a yr ago, recently the wheel cylinders had to
    be changed,
    and Im told the front pads still are in good shape. One Rotor had to be changed because
    the truck sat for 12 yrs at a dealer and it literally fused to the hu
    with the rust...one of the rear drums
    had the same thing happen, never saw that before.

    Anyhow aside from one rear brake line going out since then, been good however noticed
    if I am at a light and there is a slight incline downward like at the
    bottom of a hill, I can geel the pedal
    slowly going down. I can pump it back up but usually it still falls and
    you can hear the brakes creeking
    in the front as the pads dont grip as good and the truck starts to creep forward....so Im thinking master
    cyl, as its probably the one in there since 1998. I dont think theres
    been any fluid loss, it seems full of fluid
    and topped off.

    If in neutral seems to not happen as much...today I was at Burger King
    and just sat there on a level area
    with my foot on the pedal and it was rock solid.

    Other thing noticed dunno if its related is the drivers side rotor
    (which is new) seems to vibrate when you go down
    a fairly steep hill and ride the brake down to stay in the speed limit posted.

    I was told that in 4wd that wheel becomes the front drive wheel, not
    sure is thats important or not regarding this,
    but also both front wheel bearings were replaced last yr, and that one
    seems to have a hard time keeping the center cap
    on for a long while. I check to see if any of the hubcaps can be pushed
    in after long miles of driving and that
    one is usually a little loose and would come off eventually, already
    lost (2) of them, so I was wondering if that
    means the wheel bearing on that side is a little questionable?

    Good advice from Amuzi.
    To add to that, if you plan on keeping the truck then replace all the
    steel lines, either rebuild all wheel cylinders/calipers or get rebuilt
    ones, the master cyl seals are likely leaking. Possibly leaking into
    the vacuum booster and rotting that out, too. I've seen the brake pedal slowly going down if the brake booster is leaking vacuum internally.
    Check the one way vac valve, too. I bet you will find the mstr cyl and
    all wheel cyls full of rust if you take them apart. Replace them along
    with the steel lines.
    Rock Auto has everything you need including new steel lines. https://www.rockauto.com/en/catalog/ford,1998,f-150,4.2l+v6,1315003,brake+&+wheel+hub,brake+line,1820

    Also,
    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From UFO@techforce@nospam.gmx.com to rec.autos.tech on Thu May 28 10:23:52 2026
    From Newsgroup: rec.autos.tech

    Update

    Last night the ABS and Brake light came on.
    Checked the fluid
    and was very low, topped it off , lights are gone
    but I can see the brake line from the master to that side caliper is leaking fluid and its dripped onto the frame.

    Hopefully just a brake line....might have all the front ones done to get it over with.


    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From AMuzi@am@yellowjersey.org to rec.autos.tech on Thu May 28 09:27:55 2026
    From Newsgroup: rec.autos.tech

    On 5/28/2026 9:23 AM, UFO wrote:
    Update

    Last night the ABS and Brake light came on.
    Checked the fluid
    and was very low, topped it off , lights are gone
    but I can see the brake line from the master to that side
    caliper is leaking
    fluid and its dripped onto the frame.

    Hopefully just a brake line....might have all the front ones
    done-a to get it over with.



    The advice from Paul in Houston was correct.

    Any vehicle sitting 12 years has absorbed moisture into the
    brake fluid; new lines rebuild or replace cylinders is the
    right path.

    And not all that expensive compared to cruising through a
    red light...
    --
    Andrew Muzi
    am@yellowjersey.org
    Open every day since 1 April, 1971
    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From kludge@kludge@panix.com (Scott Dorsey) to rec.autos.tech on Fri May 29 16:05:16 2026
    From Newsgroup: rec.autos.tech

    In article <10v9jd9$27guo$2@dont-email.me>, AMuzi <am@yellowjersey.org> wrote: >On 5/28/2026 9:23 AM, UFO wrote:
    Last night the ABS and Brake light came on.
    Checked the fluid
    and was very low, topped it off , lights are gone
    but I can see the brake line from the master to that side
    caliper is leaking
    fluid and its dripped onto the frame.

    Hopefully just a brake line....might have all the front ones
    done-a to get it over with.

    The advice from Paul in Houston was correct.

    Any vehicle sitting 12 years has absorbed moisture into the
    brake fluid; new lines rebuild or replace cylinders is the
    right path.

    Flushing the fluid completely from all lines is the first step, and
    that includes the clutch lines if you have a hydraulic clutch. This
    prevents further damage from being done.

    THEN it's time to start seeeing what is failing and I would be very
    surprised if you don't have bad brake lines at all of the lowest
    points in the system and if your master cylinder doesn't have bad
    seals.

    You can rebuild the master cylinder yourself with a seal kit but it
    isn't that much cheaper than getting a quality rebuild.
    --scott
    --
    "C'est un Nagra. C'est suisse, et tres, tres precis."
    --- Synchronet 3.22a-Linux NewsLink 1.2