2002 Ford F350 4x4 7.3 srw - Driving down the road and for no reason the brakes start to apply and slows the vehicle by about 10mph. Can press accelerator to compensate but then the truck starts to shake violently. I can hear a pop under the dash about every 30 seconds sounding like some sort of vacum. After about three pops the truck will release and return as normal. Only does it speratically.

I would get your brake pads and disc's checked they my be warped or damaged.As for the turning off problem i would go get and electrical test might be the ignition coil.

FOR ONE THING CHANGE MECHANICS ! HE SHOULD HAVE FIXED THE PROBLEM, YOU MAY HAVE A SERIOUS BRAKE ISSUE ! IF LIGHT IS ON IT WILL NOT PASS INSPECTION ! YOU MAY HAVE AIR IN SYSTEM, NEEDS BLEED ! FLUID COULD BE CONTAMINATED , NEEDS BLEED OUT, REPLACED W/ FRESH FLUID ! ABS REQUIRES THAT THE REAR BRAKE CIRCUIT OPERATES BEFORE THE FRONT BRAKES, THIS PREVENTS SKIDDING, THE PURPOSE OF ABS BRAKES, CORRECT ? MASTER CYLINDER HAS SEALS, CONTAMINATED FLUID AFFECTS SEALS, BRAKE LIGHT WILL STAY ON UNTIL PROBLEM IS RESOLVED !!! REAR BRAKES IF SHOES NEED ADJUSTED, CLOSER TO DRUM ! THIS WILL HELP, BUT BLEEDING OUT ALL BAD FLUID & AIR IN SYSTEM IS PARAMOUNT !!!!!! BRAKE LIGHT SWITCH MAY NEED REPLACED, PROPORTIONING VALVE WHICH SEPARATES FRONT FROM REAR BRAKES , IS OUT OF BALANCE, THE VALVE NEEDS TO BE @ A NEUTRAL OR CENTERED POSITION, COULD BE STUCK TOWARD EITHER BRAKE CIRCUIT, MORE FRONT THAN REAR, UNDERSTAND ? THINK I COVERED YOUR ISSUE, PLEASE RATE MAY ANSWER ! THANKYOU,

Hello, lets test that BMW M5 ABS braking system, OK. First, drive down a street with no traffic. Speed up to 30 to 40 MPH. Then slam on your brakes hard, if the brake petal is pulsating and there a noise like clunk,clunk,clunk,clunk noise. Your BMW ABS is working. If not, then the BMW ABS isn't working.


ABS system and what it does to your BMW. All it amount to is it doesn't lock up the braking system. It just applied the brake and release in micro seconds. This keep the vehicle from sliding side ways on wet roads, snowy roads, icy roads or even on dry roads. In other words, it keeps the front of the BMW in a straight line.



If your BMW ABS isn't do this, you'll need to have the ABS braking system serviced. GB...stewbison

You may have three seperate issues. First, could be a brake caliper sticking. Second, the master cylinder is bad.

Finally, Number three...and most likely, your brake pads are worn out, completely.

Have your brakes inspected by a qualified individual. Hope this helps.

Anti-Lock Braking System (ABS)
Purpose Anti-lock brake systems (ABS) - generally also referred to as anti-lock
systems (ALS) - are designed to prevent the vehicle wheels from locking
as a result of the service brake being applied with too much force, especially
on slippery road surfaces.
The idea is to maintain cornering forces on braked wheels to ensure that
the vehicle or vehicle combination retains its driving stability and manoeuvrability
as far as physically possible. The available power transmission
or grip between tyres and carriageway should also be utilised as
far as possible to minimise the braking distance and maximise vehicle
deceleration.
Why ABS? Although today commercial vehicle brakes are designed to a very high
technical standard, braking on slippery roads often results in potentially
dangerous situations. During full or even partial braking on a slippery
road it may no longer be possible to fully transfer the braking force onto
the road due to the low coefficient of friction (friction coefficient (k)) between
the tyres and the carriageway. The braking force is excessive and
the wheels lock up. Locked wheels no longer provide any grip on the
road and are almost incapable of transferring any cornering forces
(steering and tracking forces). This often has dangerous consequences:
- The vehicle becomes unsteerable
- The vehicle breaks away in spite of countersteering, and starts to
swerve.
- The braking distance is significantly increased
- Tractor-trailer combinations or semitrailer trains may break away or
jackknife.
Load sensing valve influence On dry roads today's load sensing valves (ALB) alone are often capable
of preventing the wheels from locking if the vehicle is unladen; they also
help the driver to effectively grade the braking process on wet road surfaces,
but they are unable to prevent locking as such (no slip monitoring).
In addition, they are unable to counteract any overreactions on the
part of the driver, or any variances in frictional or adhesion coefficients
which may apply to different sides of the vehicle, or indeed to its different
axles (?-split road surfaces).
Benefits of ABS: Only the Anti-Lock Brake System (ABS)
- guarantees stable braking characteristics on all road surfaces.
- maintains steerability and generally reduces the braking distance
- prevents vehicle combinations from jackknifing
- reduces tyre wear.
Limits of ABS Although ABS is an effective safety device, it can not suspend the limits
defined by driving physics. Even a vehicle fitted with ABS will become
uncontrollable if driven too fast around a corner.
So ABS is not a licence for a maladjusted style of driving or failure to observe
the correct safety distance.
4
ABS Training Anti-Slip Regulation (ASR)
Anti-Slip Regulation (ASR)
Why ASR? Increasing the engine output (accelerating) on a slippery road surface
can easily lead to the maximum adhesion on one or all powered wheels
being exceeded causing them to spin, especially if the vehicle is unladen
or partially laden.
Spinning wheels when driving off or accelerating represent a safety risk
just like locked wheel do when braking.
Reasons - Wheels that spin transfer just as little cornering force as locked
wheels.
- They also no longer transfer any tractive power onto the road.
Consequences - Vehicles that do not move or get stuck.
- Vehicles that can no longer be steered, jackknife on uphill uphill
gradients, or swerve in corners.
Benefits of ASR ASR prevents the powered wheel from spinning and provides the following
benefits:
- Tractive power and cornering forces are maintained.
- Stable driving behaviour is ensured when moving off, accelerating
and negotiating corners on slippery roads.
- The indicator lamp (if installed) is used to warn the driver of slippery
road conditions.
- Tyre wear is reduced to a minimum, and the motor vehicle's drive
train protected
- The risk of accidents is further reduced.
ASR and ABS: ASR represents a worthwhile addition to an ABS-controlled braking system.
All that is required to turn ABS control into full ABS/ASR control is
an ECU with the additional ASR function and a few additional components
for controlling the differential brake and the engine. This why ASR
is only available in combination with ABS.
Even a differential lock for off-road use and ASR do not exclude but complement
each other.
Limits of ASR The traction capacity of an all-wheel driven commercial vehicle can not
be achieved by a motor vehicle with only one driving axle - not even with
optimal ASR.

Copy and paste this into your search window: 2002 ford ranger rear brake diagram

You should see four pictures pop up, select the brake parts diagram or the brake picture.

NEED NEW ROTORS

It sounds like the rear calipers are bad. Raise the rear wheels and see if you can turn the tires. If you can't, open the bleeder. If you still can't replace the caliper. If you can turn the wheel after you open the bleeder, replace the brake hose to that wheel.

i would check front and rear brakes if rears are drum brakes i would inspect springs and hardware making sure everthing is conected and in place also make sure they are adjusted properly in the front and if rear disc i would make sure to grease caliper slides these allow caliper to move and its important that all moving brake parts are free push caliper pistons in alittle to see if they are sized or not booster is ok and most of the time when master goes it will leak where it meets booster and you will have a low brake pedal or no brakes

there are too many reasons...

it could be fuel pump,, it could be ignition coil overheating, it could be the computer itself...

you need two things for the engine to run,

1 is gas
2nd is ignition,,

with these two misfiring or your loosing one of them, it will stall...

i hope i was able to give you some thoughts....

drcool