K3500 and every year the ABS wheel speed sensor goes out ( and costs me
a bundel). Then I'm left with near zero braking power in wet and
definitely snowy roads. Any thoughts on fixing this more permanently or
even disabling the sensor or ABS unit? ( I would like to maintain the
rear brakes with ABS if possible just not the front ).
Which wheel speed sensor? A bad wheel speed sensor will not cause you to
lose braking power, it will simply render the ABS inoperable.
These sensors are somewhat notorious for getting dirty and going bad.
Are you sure they are replacing it or just cleaning it. Usually they
just need to be cleaned (some overzealous mechanics like to slop grease
all over then while servicing other parts around it..)...I had to
replace mine because it was cracked...your '97 ABS is a 3 channel unit I
believe (front LT, front RT, and rear), so in theory losing a front
wheel speed sensor shouldn't cause you to lose ABS in the rear. I
thought the same thing on my '97, but that's not the case when my front
left sensor craked due to low temperature, I lost all ABS. I don't know
why the rear ABS didn't continue to function, and I don't think there is
a cheap easy way of fooling it. The sensors on these systems have a
pulse type signature that increases with vehicle speed, you would
essentially need to replicate that..you'd need to hook up an
oscilloscope and check the pulse as your driving, then build something
to replicate it..
I think the 3 channel thing just means you'll maintain braking if one of
the three channels fail with a pressure drop (leak)...
I believe there was a TSB on some of these? not sure but vaugely remember.
Anyway, some other things to ponder:
Sensor magnetic ring.
Bad wheel bearing if its allways the same sensor. Heat can destroy the
Bad connector, Check these Metripak connectors, they loose contact 'spring' over
Thanks for the insight. The dealer seems to replace the front driver
side each time. What happens is the ABS becomes over sensitive and
pulses the brakes to the point that I have like no braking power when
it's wet or I hit a slight bump on the road ( like a pot hole or RR
tracks ). I was hoping to just eliminate the sensor in the front. They
state there are no sensors in the back or passenger side.
Same thing happened to my 99 1500. If your truck has the same ABS system as
mine, then this should work. On the front hub where the plastic abs sensor
plugs in to, will rust. The rust builds up between the housing and the
sensor. This will push the sensor further away from the rotating grooved
axel shaft. If it is pushed to far away, the sensor will not register
movement. Now the system thinks it is in a full skid and will try to
compensate. It is easy to pull the sensor and scrape the rust from the axel
housing and you should not need a new sensor. This will require removing the
caliper and rotor. You might try greasing the area on the housing where the
sensor seats. This may slow the rusting process for next time. I do not
think there are any long term fixes. Very poor design by GM. I almost killed
a guy from this problem. Great safety feature!
The system will not operate the rear antilock separately
from the front unless everything is working properly.
If you lose any of the sensors, or anything in the system
is wrong so that you have the ABS light come on...the
entire system is disabled.
3 channel just means that the 2 front wheels are modulated
individually, but the rear wheels are modulated together.
A 4 channel system would modulate all four wheels
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