Taurus Car Club of America : Ford Taurus Forum banner
1 - 20 of 22 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter · #1 ·
Please all.... could use a little help , at wits end on this one. my 2002 dohc has got some braking issues. I have completely changed the rear drums, shoes and hardware. put on a reman. master cyl. from napa and bled the brakes 3 times completely. i have traction control and abs on this vehicle. the front disc brakes look to be in pretty good shape along with rotors. ok when i push on the brakes i am still getting a soft mushy pedal (which i can deal with) but at slow speeds coming to a stop 20mph on down to 0, i get a very annoying pulsating/ light thumping sound that seems to be coming from the somewhere in the engine compartment towards the drivers side.... (that i cant deal with) i am really frustrated by not being able to figure this out on my own PLEASE HELP any suggestions are greatly appreciated. by the way no abs light comes on at any time.. Thank you very much!
 

·
Registered
Joined
·
437 Posts
I find the same issues with my 2001. My brakes are in very good condition. I have ABS and Traction control. Like millions of people, ABS braking is not natural to human instincts and many people disable it. People think that they know better than the ABS reaction and think ABS is faulty or dangerous. Absolutely wrong! I find this issue every winter and hate my ABS but that ABS computer is keeping you alive and in contol of your steering by having better knowledge of your car's braking maximums! I hate it too, but I know that The ABS is smarter than the human reaction, so it is a PLUS.
 

·
Registered
Joined
·
2,425 Posts
Sounds like your ABS is engaging too soon. Tha would be because the sensors in the wheel area... But even if I know how the ABS sounds and feel, I am not there to tell for sure.
How fast is that pulsating? Like 10 times per second (ABS) or like 1 every tire rotation (warped rotors)?
 

·
Registered
Joined
·
564 Posts
I'm not sure I understand if it is just a sound or also a feel. If you feel pulsating is it just in the brakes or also in the steering? I would poke around the front suspension components too just to rule out tie rods / ball joints / related bushings.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #7 ·
update

took the car to an abs/ electrical specialist and he cant even figure out the problem, i am at a loss on this one anyone have any issues such as this?
 

·
Premium Member
Joined
·
1,043 Posts
Check the tone rings on the front axels. When these break, they can cause the sensation you are describing. It happened to me. The tone rings are 'pressed' onto the axels and are a gear that drives the ABS wheel sensor.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #9 ·
that was my initial thought also, supposedly he checked those too, and he checked the air gap from the rings to the sensor and everything checked out fine.another reason why i am pulling my hair out ...whats left of it thanks for the help though...
 

·
Registered
Joined
·
15 Posts
Is the ABS light on? If so then there is an ABS problem, the ABS computer does a Self Test of all components at each power up sequence, it will turn on the ABS light if it sees any problems.

If not then there is a problem in the basic breaking system usually.

The ABS can not be Blead like the older cars, you have to use a PRESSURE BLEEDER, and bleed it in a specific sequence at the bleed ports on the different components, sometimes you have to push as much as 2 gallons of break fluid through the system to remove all the air.

If the brake peddle pulsates while stopping, it could be warped brake rotors or rotors that have the Parallelism off. (Both Rotor Inside and Outside Surfaces MUST BE TRUE with each other, otherwise the rotor causes the brake caliper piston to move in and out while the wheel/rotor is turning, this causes the brake peddle to pulsate. You have to Turn of Replace the Rotors to get rid of these type of pulsations)

Usually Parallelism issues will show up as a slow surge while coming to a stop, fast at first and gradually slows as you come to a stop, it may shake the steering wheel and make the car shudder when stopping while going faster, then subsides as you slow down.

Hope this helps

Dusty
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #11 ·
the abs light is not on... i really dont believe that it is a rotor issue, because when coming to a stop as soon as i reach exactly 20 mph on down to a complete stop it does the pulsating and also you can hear what sounds like the abs module cycling under the hood on the drivers side.... thanks alot for your input this really has me baffled.
 

·
Registered
Joined
·
15 Posts
Hello

Get out your Owners manual, find the ABS fuse in the Fuse Panel

Road test somewhere that is COMPLETELY SAFE AND WILL NOT PRESENT A SAFETY HAZZARD TO YOU OR ANYONE ELSE, pull the ABS fuse and road test to see if the problem is still there.

TRY TO DUPLICATE THE TYPE OF BREAKING THAT CAUSES THE PROBLEM

If the problem is still there then it is the Basic Brake System, if it goes away then it is possibly in the ABS System.

If it is in the ABS, then take the car to a shop that has a Scanner that can get into the ABS Computer and components for diagnosing the problem.

I think it is the basic brake system, the ABS system would iluminate the ABS lite if it saw a problem, Puters are pretty smart these days.

DON'T FORGET TO REINSTALL THE ABS FUSE BEFORE RETURNING FROM THE ROAD TEST AREA.

Hope this Helps, DRIVE SAFE WHILE TESTING

Dusty

P.S.

Just thought of this, not sure what type of ABS you have, but some systems have a motorized pump on the ABS System where the Master Cylinder/ABS unit is located. It's function is to build braking pressure should the ABS need it in the performance of its duties.

If the ABS system sees a wheel starting to stop, it bleeds pressure on that wheel brake to get the wheel turning again, if it bleeds so much pressure that the brakes can not function properly/safely then the morotized pump starts up and builds up braking pressure again to maintain a safe braking system.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #13 ·
Thanks alot Dusty will check out a few things and see what i can come up with,will advise.....that motor that your describing sounds interesting. i will check it out again thanks a ton Dave
 

·
Registered
Joined
·
8 Posts
I just bought a Taurus and had it inspected by CAA before I did the deal. The mechanic picked up a pulstation in the brakes on his test drive (to be honest I haven't really noticed it yet) and he says it's because the brake rotors are slightly out of round and need pputting on a brake laith.

Could that be the problem or have you had the rotors changed?
 

·
Registered
Joined
·
10,953 Posts
ABS active at 20

the abs light is not on... i really dont believe that it is a rotor issue, because when coming to a stop as soon as i reach exactly 20 mph on down to a complete stop it does the pulsating and also you can hear what sounds like the abs module cycling under the hood on the drivers side.... thanks alot for your input this really has me baffled.
Long shot but easy to check.

I had this on a '02 Lincoln Cont and they fixed under warrenty.

The speed sprocket on the half shaft was loose on the cv hub. Does not seem like a likely issue but it has happened. When you slow down to a stop, the ring continues to spin enough to make the ABS think you are slipping or spinning and activate. They replaced the half shaft. I would have used 2 part epoxy. The sprocket, (speed wheel) cannot get off as it is between the boot and the bearing. The dealer told me loose sprocket has happened to other fords.

-chart-
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #16 ·
still havent figured it out

i pulled the fuse to the abs in the engine compartment, abs light and traction control light then came on, but the brakes no longer pulsate.....who knows
 

·
Registered
Joined
·
10,953 Posts
i pulled the fuse to the abs in the engine compartment, abs light and traction control light then came on, but the brakes no longer pulsate.....who knows
May be relivant, maybe not. Worth a check.

I was listening to a radio auto show this am. Well, I was doing something and it was on and I heard part of a discussion. Issue was ABS problems at low speed with no error codes. Possible it was a tone ring with a missing or damaged tooth. Most tone rings are about 50 teeth so if one is gone that is only 2% and falls inside the tolerance. BUT the gap upsets the system at low speeds. Then the discussion got to pickups were they use one tone ring for the rears and inside the dif case. Problem is the magnet picks up metal dust and sometimes chunks.

Taurus uses open tone ring. In the front it is possible to get a rock lodged and break a tooth.

Just a thought.

-chart-
 
1 - 20 of 22 Posts
Top