After Replacing Right Front Abs Speed Sensor

[RX300ES300]

Need some advice:

My 1995 ES300's ABS light was on, I figured out that FR ABS speed sensor was the problem, I bought and installed a replacement (Dorman brand) from Ebay, $80 shipping included. The sensor is bit bigger than the original, I trimmed it down with a file. After the installation, the ABS light went away, I was really happy with it at begining. The problem is now every time I brake the car, it gives me a ABS pulsation near the end of stop, even during a light brake. I know the pulsation should only happen when you brake it hard during emergency.

I did disconnect the battery trying to clear any memory in the ABS processor, the pulsation still there each time I brake the car.

Any inside view about this issue? Appreciated..

[George_Jetson]

Trimmed it down??? That's a little scarry,, (though I have done mods myself). Was the connector the same? Did you compare resistance readings with the other front sensor? What excactly needed filing? Are you sure the airgap is the same as the other wheel? Also check the wheel bearings.

So have you had the car for awhile? Or did you recently purchase it? If this is a recent purchase, has the abs ever worked since you owned the car? The reason I ask is with a open wheel sensor, the abs will not operate at all, it is possible that the new MODIFIED sensor is working correctly, and now a previous problem has re-appeared.

Also, do you have stock wheels.

[RX300ES300]

Hi George, thanks for the reply, just throw in some answer for the discussion:

I trimmed down the diameter about 1 mm, because the original hole is bit small. The trim down is the plastic casing which wraps the coil, that should not be the problem, i guess. Yes , the connector is the same. The resistance reading of the old sensor is no reading (infinite or you can call it short circuit, that's the double garrantees for a bad sensor, the other one is codes 31 and 36), the new sensor is about 1K ohm which meets the spec (0.6-1.8K), I did not measure the other front sensor, just lazy, I figure it should be fine, cause the ABS light is off. I do not know the difference of air gap of the other wheel, I do not want to take the other sensor off, cause when I took the old one off, it was fragile and stocked in the position, i have to break the old one, and clean out the part left in the hole (a lot of copper wires, copper coil) with some efforts. The wheel bearing is fine, never have any problem. the wheels are the stock, no modification.

I own this car for more than 10 years, did all the mechanic works by myself, brake/rotor, timing belt, volve cover gasket, rear bearing replacement, oxygen sensor...etc. I am just puzzled by this funny pulsation at the end low speed brake. maybe I should replace the other side, with the same brand, just to make the abs processor happy, but i am just wondering, theoretically, why? should the computer chip adjust it accordingly? even the sensors are slightly different?

Some thing happened this afternoon, I drove slowly on the local road with the ac one, just after i braked and before I parked the car, the ABS light flickers (of cause the pulsation was there), then went away, then it did not happen again. It is tricky, isnt it??

[RX300ES300]

The problem resolved. Just to share the information with all members:

Discussed the issue with the parts maufacturer, the tech people is really nice, he indicated that the gap distance between the sensor and the trigger wheel is very important, even a very small difference (in millimeter) will cause the problem.

I cleaned the area where the sensor is located thoroughly, some debris were noticed and removed. Unfortunately, when I tried to put everything back, I broke the screw which ties the sensor down. Took me extra two hours to extract the broken screw. Anyway, I test drive the car after putting everything back, The ABS behaves flawless just like new.

Hope this helps .