Hi and Welcome to Just Answer! My name is XXXXX XXXXX X will do my best to help. do you have disc or drum brakes at the rear axle?
if drum brakes at rear, first thing to do is to make sure brake shoes are properly adjusted
Disc all the way around
let me run out to garage and check.. but I believe disc
ABS unit can develop internal leak, as it has dump valve built inside.
yes.. disc in rear
that's what i've read
strong pedal at first to brake.. then it won't hold.. slowly goes down to floor
plus with engine off.. the brake is firm and doesn't fade.. so m/c is ok I think
2001 w/ 130K miles..
any other ideas.. ABS was my next thought.. can i test it ?
no light on the dash.. but w/ key on.. abs lights up.. so circuit is working
ABS unit on F150 is known for problems and leaks.
I have replaced many of them
so this is most likely better way to go, new from dealer is around 700 dollars
light would be on all the time huh..
you can create plugs and plug lines coming out of the unit
only leave the onnes going in
4 wheel abs or just 2 w/ this year?
but there is nothing else that can cause this
leave lines going in but plus those coming out.. brakes will still work
no, do this only for testing
oh I see.. if it holds pressure or not.. similar to plugging the m/c to test it...
if you want to by pass you will have to buy and incorporate proportioning valve
as truck has a lot more weight at the front
and this will change when loaded
ok.. i've heard alot about that too.. it's built into ABS unit?
the fastest thing to do is just to replace the ABS unit and you are back on the road
ok.. I will plug and test first. to make sure it's the abs unit.. so this is a common thing on f150's..
yes, this is correct.
also make sure that push rod between brake booster and muster cylinder is properly adjusted
your pedal will go soft when engine is started
but it must stop 1/2 of it's travel
when you apply normal force pressing on the pedal
you do not have to press extreemly hard when testing it
that's about right.. there's some play before brakes engage.. but there's still alot of travel left after that
some vehicles may have a bit softer feeling pedal
do drive test
if your vehicle stops normally then there is nothing wrong with the truck
brakes seem to engage quickly with reasonable pedal travel.. then pedal fades.. won't hold pressure etc..
oh.. measured push rod too before installing new m/c.. seemed right based on length to inside of m/c.
so this rod is ok to adjust then.. I turned it out a little bit.. not much
rod must touch master cylinder as muster touches booster body, it is like almost 0 clearence
ok.. that seems how it is..
if you apply brake (without fording the pedal and keep it this way, doe struck moves forward?
sorry I mean without forcing the pedal
it stops.. but then pedal fades and truck creeps..
when bleeding the brakes, do you have good pressure at each wheel?
a shop bled them for me.. he said he bled them a couple times.. no air.. but no improvement in the fading brake pedal.. so he suggested new m/c .. did that.. no change
i suggest one more bleeding.
start with right rear
do not stop to bleed until good pressure
have engine running as you bleed the system
then left rear
right front and left front
with engine running you will have help from booster
and this will give better pressure
on the way to shop brake hard few times to activate ABS pump
or you can bleed it your self
yah.. I pretty sure I can do the bleeding.. with help from a friend .. I will try this first.. the low cost approach.. brake hard first to activate the abs pump.. then bleed
thanks for all your advice.. Pavlin..
You are welcome!
thank you for using just answer and have a Happy Holidays!
I will accept of course.. then save our chat for reference.. you too Merry Christmas!