Abs alarm will not stop

Leak in your line

Something is wrong with your statement
it is a 99 caravan 3.3 no abs , then you are on about abs light pump etc
the abs pump only works when the master cylinder is under pressure and that pressure is suddenly reduced by the sensor reading a locked wheel and a valve is opened to release line pressure to that wheel As soon as that wheel starts to turn, the valve closes
while the wheel is stopped and that valve is open , the abs pump kicks in to maintain line pressure otherwise the brake pedal would go to the floor
master cylinders work through a. abs unit and not because of it so if the master cylinder becomes faulty, the abs pump will not operate until a wheel stops turning as there is no line pressure to stop a wheel turning
the abs light may not be on because there is nothing to operate the system to put it on

1: inspect all brake linings first.
no pulling left or right braking?
the car has 100% full manual brakes. if the brake booster fails.
(its only and assist !!! for 50lb small folks)
so does it? it takes more pedal pressure but has 100% full braking.
this is no accident its by design.
make sure none of the brake shoes/pads are soaked in DoT3/4 fluid
or grease or gear oil.
and no brake fluid leaks end to end, this is really #1 on all cars.
look, then look again. even behind and in front of the master cylinder.
look at tires (inside for fluid leaks>)
2: do the booster test. did the vacuum hose to it fall off?
or got pinched, or ?

google brake booster test
if ABS system. get it all checked,
if ABS get the ABS scanned.

if you cant stop correctly,,,,???? , dont drive.
get it fixed.

Needs to have code reset for abs by a obd2 code reader with abs or find a parts house or shop that will reset it. Brake light coming on did you bleed the master cylinder out by connecting rubber lines to ths plastic insert ******* then acuating the master cylinder til all air is pumped out of master cylinder if that was not done then you will need to bleed all brakes until air is out of system that should turn brake light off

are you loosing brake fluid? do you notice any leaks? it could be a bad master cylinder or a bad proportioning valve, master cylinder is more common failure.

Sounds like the abs master cylinder area is in need of replacement if the abs fuse is removed and stops better.

Chattering can occur in an abs system when the system senses wheel lockup on that wheel and attempts to anti lock that wheel.

Could also be a wheel speed sensor not working, properly.

Hope this helps.

with some abs systems you have to do an intesive bleed but you need the mercedes star diagnostics machine because its a set programme.

I would replace the MASTER CYLINDER. BLEED AIR from master cylinder BEFORE INSTALLATION. Hope this helps

honestly sound more like the abs unit, it is the alloy box that the brake lines go into from your master cylinder, this will cause directional braking and awkward braking and DANGEROUS braking, it is more than likely the abs junction box and no the computer will not need program, just disconnect battery for 15 mins while doing the work. hope this has been helpfull

Sounds like need new Calipers for front too. Maybe a new master cylinder may be need too. Sound like to Calipers or master cylinder are now letting to brake fluid go back to the master cylinder.